Anesthesia Oral Boards Flashcards
Side effects of glucagon
Increased heart rate and transient hyperglycemia
Rx for SIADH
Fluid restriction and demeclocycline: inhibits renal action of ADH, induces diabetes insipidus, alternative to demeclocycline is tolvaptan, a vasopressin receptor antagonist
Hyponatremia, euvolemia
SIADH, postop pain/stress, diuretics, hypothyroidism
Hyponatremia, hypovolemia, urine Na less than 10 mEq/L
Non renal solute loss: GI losses, skin, insensible
Hyponatremia, hypervolemia, urine Na greater than 20 mEq/L
Renal failure
Clinical features of hypernatremia
Lethargy, confusion, irritability, coma, seizures, nausea, myoclonus, tremors, muscle weakness, intracerebral bleeding
Clinical features of hyponatremia
Asymptomatic: greater than 125
Anorexia, nausea, malaise: 120-125
Headache, lethargy, confusion, agitation, obtundation: 110-120
Stupor, seizures, coma: less than 110
Drugs that cause hyperkalemia
Succinylcholine, beta blocker, ACE inhibitors, heparin, severe digitalis toxicity, cyclosporine
Diagnosis of DKA
Serum ketones > 7 mmol, serum bicarbonate < 10 meq/L, pH < 7.25
Labs to order when suspecting DKA
Urinalysis, glucose, electrolytes to determine anion gap, ABG, CBC to check for infection
Treatment for DKA
IV fluids, insulin bolus then gtt, potassium as acidosis is corrected, antibiotics for sepsis
Diagnosis and treatment of nonketotic hyperosmolar coma
Severe dehydration, no ketoacidosis, glucose very high like 1000 mg/dL, mental status changes.
Treatment: IVFs, insulin, dextrose, potassium
Anesthetic considerations for diabetic patients
Renal dysfunction; increased risk of CAD and CVA and PVD; autonomic dysfunction: delayed gastric emptying, orthostatic hypotension, resting tachycardia; infection and poor wound healing; stiff joints; poor response to ephedrine
Drugs that precipitate when mixed with barbiturates
Vecuronium, atracurium, midazolam, sufentanil, alfentanil
Sevoflurane has potential for emergence delirium and can be switched to what agent after induction?
Isoflurane
Sevoflurane given at flow rates less than 2 liters can cause what?
Formation of compound A with is nephrotoxic
Which volatile agent has greatest risk of degrading to form carbon monoxide in extremely dry CO2 absorber?
Desflurane
Virchow’s triad for venous thromboembolism
Venous stasis, vessel wall damage, hypercoagulability
Diagnostic triad for fat embolism syndrome, ways to reduce incidence/severity.
Hypoxemia, altered mental status, petechiae (12-72 hours after initial trauma), pulmonary edema. Early immobilization of fractures, limit intraosseus pressure, operative correction rather than traction alone
Triad of symptoms for severe aortic stenosis
Syncope (3 yr mortality rate is 50%), angina (5 yr mortality rate is 50%), dyspnea (2 yr mortality rate is 50%). Valve area < 1.0 cm^2, mean gradient > 40 mmHg, aortic jet velocity > 4.0 m/s
Risk of occurrence of venous air embolism in sitting crani, and why is risk greater in sitting vs prone position?
76%. Horizontal position still has 12% risk of occurrence. Sitting position increases the pressure gradient favoring entry of gas into the veins that now have less than atmospheric pressure because they are above the heart.
Why is nitrous oxide avoided in surgical procedures where there are closed air spaces
Nitrous oxide has blood gas coefficient of 0.47 compared to 0.015 of nitrogen, so nitrous oxide will enter closed gas filled spaces 34 times faster than nitrogen can diffuse out.
Oliguria is < 0.5 mL/kg/hour of urine for how many hours?
6 hours, or < 500 mL in 24 hours for adults, or < 1 mL/kg/hr for an infant.
Intraoperative narcotic of choice for ESRD patient
Fentanyl: primary liver metabolism and no active metabolites
Morphine: one small dose is okay but its metabolite 6-glucuronide can lead to prolonged respiratory depression
Meperidine: do not use. Its metabolite normeperidine is neurotoxic, leading to convulsions.
Signs associated with post-op jaundice due to halothane anesthetic toxicity
Fever, rash, eosinophilia
Antepartum bleeding and maternal cocaine use
Placental abruption. Also associated with excessive alcohol use and smoking
Anesthesia of choice for obstetrical antepartum bleeding in setting of coagulopathies, uncontrolled hemorrhage, and hemodynamic instability
General anesthesia with arterial line to guide volume resuscitation and frequent blood draws
3 C’s of signs and symptoms associated with tracheoesophageal fistula
Coughing, choking, cyanosis
How would you induce anesthesia for epiglottitis and when would you extubate?
Inhalational induction with sevoflurane and nitrous oxide to maintain spontaneous ventilation. Extubate after 24-48 hours of antibiotics and steroids, and epiglottic swelling and clinical signs resolved.
Paroxysmal sweating, hypertension, and headache is the classic triad for?
Pheochromocytoma, other signs include flushing, tremors
Treatment for thyroid storm
Large doses of propylthiouracil, fever reduction, IV fluids, steroids, beta blockers, sodium iodide, cdigoxin for afib with RVR
How is cervical spine cleared?
Alert, non-intoxicated patient without neck pain, tenderness to palpation, depressed level of consciousness, distracting injury, or neurological abnormality or symptoms can be clinically cleared
How would you assess volume status?
Vital signs, mucous membranes, cap refill, skin turgor, listen to lungs, urine output, blood loss, CXR, arterial line pulse pressure variation or systolic pressure variation, ultrasound of IVC looking at collapsibility
Methods to reduce ICP
No venous obstruction, elevating head, mannitol, furosemide, barbiturate, hyperventilation, hypothermia.
Adverse effects of hypothermia
Coagulopathy, cardiac dysrhythmias, impaired renal function, poor wound healing, delayed emergence, impaired enzyme function, shivering leading to increased oxygen demand by 400%
What would you do if patient becomes hypotensive, desats, high peak pressures
100% O2, hand ventilate, check machine, auscultate chest, verify correct position of ETT, check depth of anesthesia. Consider vasopressors, CXR, ABG, TEE.
Diagnosis of ARDS
Identifiable cause, acute onset, diffuse bilateral infiltrates, PaO2 to FiO2 ratio less than 200, PAOP < 18
Deleterious effects of supraphysiologic doses of steroids
Sepsis, hyperglycemia, pneumonia, poor wound healing, immunosuppression, electrolyte imbalance
How to assess pulmonary status of a COPD patient
I would perform a history and physical, focusing assessing severity of COPD by asking about cough, sputum production, frequency of infections/exacerbations, exercise tolerance, hospitalizations, efficacy of past treatments. If severe signs and symptoms, consider ordering CXR, PFTs, ABG, pulmonary consult.
How can PFTs help assess pulmonary status
Type and severity of disease, baseline function, responsiveness to bronchodilators (12-15% increase in FEV1)
Risks of poor perioperative glucose control (hyperglycemia)
Poor wound healing, increased rate of infection (high glucose impairs WBC activity), osmotic diuresis, worse neurological outcomes following traumatic brain injury (increased inflammation, ischemia, edema, and vasospasm).
Preop lab work for diabetic person
Identify end organ disease associated with poorly controlled diabetes: CBC, BUN/Cr, K, glucose, urinalysis, recent EKG
How to assess risk of perioperative alcohol withdrawal symptoms
History of consumption; signs of cirrhosis, hepatic encephalopathy, cardiomyopathy; labs including electrolytes and LFTs; EKG and CXR
Anesthetic concerns of chronic alcohol abuse
Increased MAC, cognitive impairment, cardiomyopathy, cirrhosis, electrolyte abnormalities, GI bleeding, thrombocytopenia
What to do if there is significant reduction of SSEP/MEP signals
1) Optimize oxygen delivery: oxygenation, ventilation, circulation, hematocrit.
2) make sure anesthesia depth has remained stable. 3) Ask surgeon to rule out surgical cause.
What to do if delayed emergence is unknown after ruling out residual anesthesia, residual neuromuscular blockade (twitch monitor), metabolic derangements (check electrolytes, glucose, ABG, lactic acid), hypothermia.
Perform neuro test of reflexes, consult neurologist, order EEG, order CT of head and neck
Which patients are at high risk for developing posterior ischemic optic neuropathy?
Prolonged procedure (> 6.5 hours), substantial blood loss (> 45% of estimated blood volume)
How can you reduce risk of perioperative vision loss for high risk patient undergoing prone surgery
Place head in neutral position at or higher level of heart, arterial line to maintain blood pressure near baseline, monitor hematocrit levels
How would you evaluate cardiac status of a patient with CAD and CHF
I would start with a focused H&P, from the history I would want to know functional status; signs and symptoms of angina, JVD, pedal or pulmonary edema; previous medical interventions. From the physical, I would assess vital signs and listen to the heart and lungs for murmurs and rhonchi. Finally, I would obtain further cardiac testing if it would change my anesthetic management.
Advantages and disadvantages of regional anesthesia for CEA
Advantages: Greater hemodynamic stability, avoiding intubation and associated sympathetic response, continuous neurological assessment of an awake patient.
Disadvantages: Requires high level of patient cooperation, difficulty of converting to GA
Options for neurological monitoring for cerebral ischemia in a patient under GA for CEA
Stump pressure, EEG, SSEP, transcranial Doppler, cerebral oximetry
What is pharmacologic preconditioning?
Drugs such as volatile agents as low as 0.25 MAC may limit infarct size, prevent dysrhythmias, and preserve myocardial function.
What causes barking cough with inspiratory stridor post extubation
Post-intubation croup, which develops secondary to edema formation (tx: racemic epi, decadron). Differential includes other extrathoracic airway obstructions like epiglottitis, foreign body, laryngotracheobronchitis
Anesthetic concerns in someone with ESRD
Electrolyte abnormalities, metabolic acidosis, cardiac conduction blockade, LVH/CHF, hyperglycemia, altered drug clearance, anemia, platelet dysfunction, volume status
How is chronic anemia well tolerated in a patient with ESRD?
metabolic acidosis and increased levels of 2,3-DPG cause rightward shift of the hemoglobin-oxygen dissociation curve, which facilitates offloading of oxygen from hemoglobin
Routine labs for patient with ESRD
CBC for anemia; electrolytes for Na, Ca, K; EKG for hypertrophy, arrhythmia, ischemia; CXR for fluid overload and pulmonary status; coagulation studies if doing a regional anesthetic.
What to do when blood pressure decreases intraoperatively?
Recheck BP, ensure adequate ventilation and oxygenation, check appropriate depth of anesthesia, check EKG for signs of ischemia or arrhythmias, check surgical field for bleeding, place patient in trendelenburg position, give fluid bolus, give vasopressor
How can capnography identify cause of hypoxia?
CO2 waveform can identify esophageal intubation, obstructive lung disease, inadequate muscle relaxant, incompetent ventilatory valves
Causes of hypoxia shortly after intubation, and what would you do
Inadequate ventilation, esophageal intubation, right mainstem bronchial intubation, bronchospasm, atelectasis, poor pulmonary compliance, ETT obstruction/kink. To do: Check monitors, hand ventilate with 100% fio2, auscultate lungs, deepen anesthetic, suction ETT, pull back ETT, give albuterol, give recruitment breath, place patient in reverse trendelenberg
Anesthetic plan to prevent perioperative sickling in a patient with sickle cell disease.
Avoid hypoxemia, hypotension, hypothermia, hypovolemia, and acidosis. Maintain hematocrit above 30% and provide adequate pain control.
Succinylcholine causes severe masseter muscle rigidity, what is the likelihood of malignant hyperthermia and what would you do?
50%, if caused by volatile anesthetic then it is 100%. Overall, 1% of children develop masseter spasm. If ventilation difficult, call for help, attempt nasal intubation, prepare for surgical airway, monitor temperature and etCO2, cancel case, monitor patient for 12-24 hours, check CK and acid-base status and electrolytes, place foley and arterial line, followup testing for MH susceptibility.
How would you prepare a hyperthyroidism patient for emergent surgery?
Minimize risk of hemodynamic instability (fluid resuscitate), cardiac arrhythmias (beta blockers), and thyroid storm by continuing PTU, giving beta blockers and glucocorticoids and sodium iodide
Preop workup for cirrhosis patient
Determine severity of hepatic disease by performing thorough history and physical, jaundice, bleeding, ascites, encephalopathy. Labs including CBC, liver enzymes, electrolytes, bilirubin, albumin, coags, ammonia
Signs and symptom of a post dural puncture headache (PDPH)
Frontal-occipital headache that is postural, nausea, vomiting, neck stiffness, back pain, visual and auditory disturbances
Clinical symptoms and diagnostic testing of a pulmonary embolism
Tachycardia, dyspnea, cough, fever, hypoxemia, JVD, hemodynamic instability, EKG changes such as new RBBB or ST changes. Testing: CT, CXR, d-dimer, echocardiogram, pulmonary angiography (gold standard)
Differential for postpartum headache
Tension headache (most common), migraine, lactation, pneumocephalus, pre-eclamtpsia, meningitis, subdural hematoma, caffeine withdrawal, sinusitis, PDPH
Concerns following cervical spinal cord injury
Respiratory dysfunction, hypotension from loss of cardioaccelerator fibers, aspiration, difficult airway, loss of thermal regulation, arrhythmia, end organ ischemia. Long term: autonomic dysfunction, risk of hyperkalemia, risk of pneumonia
What is spinal shock?
Following acute spinal cord transection, there is flaccid paralysis, ileus, loss of sensation and reflexes and sympathetic tone and temperature regulation. It usually lasts 1-3 weeks.
Why is hydroxyurea used to treat sickle cell anemia?
It increases circulating HbF, which reduces rate and extent of HbS. Reduces sickle cell crises by reducing adhesion of sickled RBC to endothelium, reducing neutrophil activation, and causing nitric oxide-induced vasodilation.
Pathophysiology of sickle cell disease
Genetic hemoglobinopathy with mutation of chromosome 11, substituting amino acid valine for glutamic acid. HbS molecules polymerize in presence of hypoxemia (paO2 < 50) causing deformation of RBC into a sickle shape, leading to hemolysis and microvascular occlusion and ischemic end organ injury.
How would do you evaluate a sickle cell anemia patient?
I would start with a focused HandP. From the history I would want to know the severity and frequency of vaso-occlusive crises, history of acute chest syndrome or complications from transfusions, cardiac sequelae (CHF, MI, arrhythmias), lung sequelae (pHTN, pulmonary fibrosis), renal insufficiency, CNS sequelae (CVA, seizures, ICH). From the physical I would assess the vital signs, check volume status, and listen to the heart and lungs. Finally I would obtain studies such as BUN/Cr, hgb, EKG to help determine severity of multi organ dysfunction.
How would you evaluate a patient with preeclampsia
I would start with a focused HandP. From the history I would want to know recent BPs and platelet counts, signs and symptoms of coagulopathy, any headaches.
From the physical, I would assess the vital signs, perform a careful airway exam, and check volume status.
Finally I would obtain studies such as platelet level, hemoglobin, coags, type and screen.
How would you evaluate an obese patient
I would start with a focused H&P. From the history I would want to know NPO status, functional status, h/o OSA (restrictive lung disease), pHTN, difficult airway, early satiety. From the physical I would assess the vital signs, perform a careful airway exam (rapid desaturation and decreased FRC), listen to the heart and lungs. Finally I would obtain studies such as EKG, CXR, and depending on comorbidities.
Minutes after delivery, mother complains of dyspnea and then begins seizing. Differential?
Amniotic fluid embolism, LAST, eclampsia, intracranial hemorrhage, hypoglycemia
Signs and symptoms of amniotic fluid embolism.
Abrupt and rapid deterioration with hypoxia, hypotension, DIC, pulmonary edema, altered mental status and seizures. Tx: ABCs, supportive care.
Nitrous oxide should be avoided for how many days following retinal detachment surgery?
Depends on type of gas injected:
5 days for air
10 days for sulfur hexafluoride
30 days for perfluoropropane
Clinical presentation and treatment of acute chest syndrome in a sickle cell patient
Wheezing, chest pain, fever, tachypnea, cough, hypoxemia, pulmonary infiltrate. Rx: O2, bronchodilators, incentive spirometry, chest PT, antibiotics, adequate pain control, correct anemia.
Tx for pseudotumor cerebri
Carbonic anhydrase inhibitor (acetazolamide) to decrease CSF production, furosemide, corticosteroids, serial lumbar punctures, ventriculoperitoneal shunt
Abdominal compartment syndrome diagnosis triad
Elevated intra-abdominal pressures (NGT or foley), significant abdominal distension, end organ dysfunction (renal, cardiac, hepatic)
Universal blood type of FFP (fresh frozen plasma) donor
AB blood type
Do platelets have to be ABO compatible?
Not necessarily, whole blood derived platelets have very little plasma so non-ABO compatible is not clinically significant. Platelets in apheresis packs are suspended in plasma so ABO compatibility is necessary.
Propofol infusion syndrome clinical presentation, treatment, prognosis.
Metabolic acidosis, bradycardia, rhabdomyolysis, lipemia, fatty liver, renal failure, cardiovascular collapse. Tx: discontinue propofol, supportive care, possibly hemodialysis. Prognosis: poor, 80% mortality
Why should you be concerned if the drainage bag of an external ventricular device falls from the bed to the floor?
Significant change in the height of the bag places patient at risk for sudden and dangerous changes in intracranial pressure
Downsides to treating acidosis with sodium bicarbonate
More CO2 formation, excessive sodium load, development of hypokalemia, leftward shift of oxyhemoglobin dissociation curve
What issues can significant acidosis cause?
Dysrhythmias, hypotension, myocardial depression, catecholamine resistance.
Patient conditions needed to reliability use pulse pressure variation to assess volume status
Sinus rhythm, mechanical ventilation of at least 8 mL/kg of tidal volume, no significant changes to chest wall compliance.
Large A-a gradient in neonate with congenital diaphragmatic hernia is caused by what?
Hypoplastic lung causing intrapulmonary shunting and pulmonary hypertension, then pHTN causing extrapulmonary shunting. A-a gradient > 500 predicts poor prognosis. A-a gradient < 400 predicts survival.
Initial treatment for patient with congenital diaphragmatic hernia
Medical stabilization to reduce pulmonary hypertension and achieve preductal oxygen saturation > 85%. Mechanical ventilation to help resolve hypoxia and hypercarbia and acidosis, all of which exacerbate pHTN. Consider pulmonary vasodilator like nitric oxide, inotrope like milrinone. Last resort to initiate ECMO.
Complications and contraindications of ECMO, extracorporeal membrane oxygenation
Complications: Intracranial bleeding and pulmonary hemorrhage, emboli, infection, vascular trauma.
Contraindications: gestation < 34 weeks, weight < 2kg, significant intracranial hemorrhage, congenital heart disease
Complications associated with umbilical vein catheterization
Infection, hemorrhage, vein thrombosis, portal cirrhosis, endocarditis, liver abscess
Complications associated with using umbilical artery for drug administration
Air embolism, vasospasm, exsanguination
How does pregnancy in a trauma patient affect management?
Left uterine displacement, difficult airway, aspiration risk, low O2 reserve from decreased FRC and increased O2 demand, hypercoagulability, fetal monitoring, fetal affects of opioids and ionizing radiation.
Rhogam (anti-Rh antibodies) are given within how many hours of delivery or trauma?
72 hours. Rhogam prevents Rh isosensitization which is when maternal IgG antibodies are produced by a Rh negative mother when blood from a Rh positive fetus enters maternal circulation
Difference between omphalocele and gastrochisis
Omphalocele occurs at base of umbilicus, has membranous covering around herniated viscera, associated with diaphragmatic hernia and trisomy 21 and exstrophy of the bladder and cardiac abnormalities. Gastroschisis occurs lateral to the umbilicus, exposed viscera, less likely associated with congenital abnormalities.
How would you intubate a neonate with an omphalocele?
First perform a careful airway exam, recognizing possible macroglossia. Then ensure presence of appropriate airway equipment, intravenous access, and monitoring. Next, decompress stomach with NG tube given increased risk of regurgitation and aspiration. Assuming reassuring airway exam, perform rapid sequence induction and secure airway with an appropriately sized cuffed endotracheal tube. If airway was not reassuring, I would perform an awake intubation.
What is the pathophysiology of retinopathy of prematurity
Abnormal neovascularization of the retina in premature infants less than 44 weeks postconception age, can lead to blindness or retinal detachment. Risk factors include prematurity, underweight, hyperoxia, hypotension, sepsis, hyperglycemia. Retinopathy of prematurity can occur in absence of oxygen supplementation.
Cause of significant difference between pre and post ductal oxygen saturation in a newborn
Coarctation of the aorta, significant right to left shunting
When does fetal heart rate variability begin to develop?
25-27th week of gestation
How long should you continue giving dantrolene to treat malignant hyperthermia?
24-48 hrs because up to 25% of patients relapse within the first 24 hours, max dose is 10 mg/kg
Advantages and disadvantages of using centrifugal or roller pumps for CPB
Roller advantage: pulsatile flow (theoretically improves renal and cerebral perfusion), not sensitive to preload or afterload. Roller disadvantage: more damage to RBCs, potential to deliver air to patient.
What is alpha stat and pH stat strategies?
These are strategies to manage CO2 in a hypothermic patient when CO2 solubility increases so pH increases and paCO2 decreases. pH stat strategy is to add CO2 to maintain pH of 7.4 and paCO2 of 40. Alpha stat strategy is to not add CO2. In adults, brain injury is thought to be caused by embolic events, alpha stat is preferred because pH stat would increase cerebral blood flow. In kids, brain injury is thought to be caused by ischemia, pH stat is preferred because it increases cerebral blood flow to help facilitate cerebral cooling. Most practitioners use pH stat.
Why monitor core and peripheral temperature during CPB?
Ensure adequate cerebral cooling prior to bypass and adequate normothermia prior to weaning off bypass. Also a temperature gradient develops during cooling and rewarming, gradient > 10C can lead to formation of gas bubbles in the blood
Causes of CPB venous reservoir level decreasing and what would you do?
Problems with venous cannulation, inadequate diameter, kinking, malpositioning, obstruction by thrombotic material, surgeon lifting the heart. I would ask perfusionist to add fluid to blood volume to prevent reservoir from emptying, which could cause massive arterial air embolism.
Causes of increased pulmonary artery pressure and decreased systemic pressure during weaning of CPB
This scenario is left ventricular failure, which can be caused by: graft failure (air, kink, clot), inadequate myocardial preservation, inadequate coronary perfusion (hypotension, emboli, spasm, decreases diastolic time), MI, valve failure, inadequate preload (hypovolemia, loss of atrial kick), hypoxemia, acidemia, electrolyte abnormalities, reperfusion injury.
What electrolyte abnormalities are seen in a patient with pyloric stenosis?
Hypokalemic, hyponatremic, hypochloremic metabolic alkalosis
Causes of atrial fibrillation and preop evaluation
Valvular disease, LVH, CAD, cardiomyopathy, sick sinus syndrome, pericarditis, idiopathic, hyperthyroidism, PE, excessive alcohol or caffeine intake. Preop: evaluate CAD, CHF, thyroid dysfunction by reviewing EKG, CXR, any previous cardiac testing
Indications for cardiac catheter ablation.
Symptomatic SVT, inefficacy or intolerance of antiarrhythmic drug, patient preference, noncompliance to drug regimen.
Causes of syncope
Cardiac arrhythmia, TIA, hypoglycemia, MI, vasovagal, orthostatic hypotension, aortic stenosis, vertigo, seizure, hypertrophic cardiomyopathy
Treatment of status asthmaticus
Supplemental O2, inhaled bronchodilators like albuterol and atrovent and aminophylline, IV steroids, IV epinephrine, order PFTs and ABGs to monitor adequacy of oxygenation and ventilation and response to treatment, consider mechanical ventilation if patient fatigues or oxygenation/ventilation is inadequate, low TVs and peak pressures and prolonged expiratory phase and consider PEEP.
How would you prepare a severe asthmatic for emergency surgery
Optimize asthma by continuing current meds, give a stress dose of steroids, benadryl to prevent histamine-induced bronchoconstriction and anxiety-induced bronchospasm, give albuterol prior to induction; control pain with fentanyl, avoiding histamine releasing narcotics; minimize risk of aspiration by giving metoclopramide; prevent/treat nausea with ondansetron
How would you induce general anesthesia in a severe asthmatic for emergency surgery
Goal is achieve adequate depth of anesthesia to avoid bronchoconstriction while minimizing risk of aspiration. Ensure premeds given to reduce risk of aspiration and nausea and bronchospasm, proper airway equipment, IV access, monitors. Assuming reassuring airway, give albuterol, preoxygenate with 100% O2, give fentanyl and lidocaine to blunt sympathetic surge from laryngoscopy, cricoid pressure, RSI with propofol and succinylcholine.
Anesthetic goals in a patient with mitral valve prolapse
Goal is to avoid left ventricular emptying because reduction in diameter of the left ventricle can worsen MVP which would exacerbate mitral regurgitation. Thus, avoid sympathetic activation, maintain SVR and preload (avoid hypovolemia, upright positioning, and aggressive positive pressure ventilation).
Pathophysiology of anaphylaxis
Second exposure to an antigen that previously caused production of antigen-specific IgE antibodies, degranulation of mast cells and basophils releases histamine, leukotrienes, prostaglandins. Leading to increased capillary permeability, peripheral vasodilation, bronchoconstriction, negative inotropy, coronary artery vasoconstriction.
Treatment of anaphylaxis
Tell surgeon, stop all current medication administration, call for help, decrease anesthesia, 100% O2, open up IV fluids, give IV epinephrine (start at 100 mcg if complete cardiac collapse, 10 mcg if just hypotensive), IV steroids, diphenhydramine, H2 blocker like famotidine, inhaled beta2 agonist, consider vasopressin or bicarb if hypotension refractory. Send for serum tryptase and histamine levels.
Significance of abnormal fetal heart rate variability
Can be sign of fetal hypoxia, fetal sleep state, fetal tachycardia, prematurity, congenital anomalies, CNS depressants like opioids or magnesium
what is carcinoid syndrome and how is it diagnosed?
carcinoid tumor releases hormones such as serotonin, histamine, and bradykinin that cause symptoms including skin flushing, bronchoconstriction, diarrhea, right sided heart failure, hemodynamic instability. Dx: 24 hour urine levels of 5-hydroxyindoleacetic acid (5-HIAA), a breakdown product of serotonin. Imaging can also help localize the tumors.
what to do preoperatively to reduce risk of carcinoid crisis in a patient with carcinoid syndrome?
start octreotide (reduces secretion of serotonin), optimize intravascular volume, anti-histamines, alpha and beta blockers, steroids
pathophysiology of aspiration pneumonitis
gastric material cause atelectasis, pulmonary edema, alveolar hemorrhage, hypoxic pulmonary vasoconstriction. signs include hypoxemia, tachypnea, wheezing, tachycardia, coughing, bronchospasm, taking 6-12 hours to show up in radiographic findings.
what to do if line-isolation monitor alarms
LIM alarms when potential flow of current from power supply to ground may place patient at risk for macroshock. Check gauge, if between 2 mA and 5 mA, too many pieces of electrical equipment plugged in, creating leakage current. If gauge > 5 mA, likely a faulty piece of equipment is plugged in, so start unplugging until alarm stops. Does not protect from microshock (10 microAmps) that can disrupt cardiac function
How does ESWL, extracorporeal shock wave lithotripsy, disintegrate renal calculi?
Sudden vaporization of water by an energy source generates a pressure wave that releases compressive energy causing shear forces when it encounters a sudden change in impedance like the tissue-stone interface. Tissue injury can occur, like bruising and hematuria
AICDs and pacemakers are recommended to be checked within the last how many months?
6 months for AICD
12 months for pacemakers
Most postpartum peripheral nerve palsies are obstetric in nature due to?
Extreme positioning, instrumentation during vaginal delivery, baby’s head compressing nerves while crossing pelvic brim.
Options for regional anesthesia other than epidural for vaginal delivery
Paracervical block for 1st stage of labor, pudendal block for 2nd stage of labor. Paracervical blocks have high risk of fetal bradycardia and decreases uteroplacental perfusion. Pudendal blocks have low risk of hematoma and abscess formation.
Risk factors for disseminated intravascular coagulopathy (DIC) in peripartum setting and non-obstetric.
Amniotic fluid exposure, hypovolemia, preeclampsia. Burn, trauma, sepsis, blood transfusion, cancer
What is disseminated intravascular coagulopathy (DIC)?
Pathological activation of coagulation cascade leading to consumption of coagulation factors, increased PT and PTT, decreased fibrinogen and platelets. Treat hypovolemia, hypoxemia, and acidosis while starting replacement of coagulation factors.
what is respiratory distress syndrome?
premature infants usually < 35 wks gestation will have insufficient surfactant production leading to tachypnea, intercostal retractions, tachycardia, rales, cyanosis
Potential complications with a premature neonate undergoing surgery?
retinopathy of prematurity, postoperative apnea, intraventricular hemorrhage, hypothermia, hypoglycemia (reduced renal tubular reabsorption of glucose when < 34 wks)
FiO2 should be decreased to minimize risk of retinopathy of prematurity for a neonate so PaO2 and O2sat are maintained at what levels?
PaO2 50-80 mmHg, O2sat 87-95%
Risk factors for retinopathy of prematurity
prematurity, low birth weight, major fluctuations in oxygen saturation, hyperoxia, hypoxia, mechanical ventilation, respiratory distress, acidosis, anemia, hypercarbia, blood transfusion, bradycardia, infection,
What are your considerations for transfusing blood in a premature neonate with a patent ductus arteriosus
Presence of fetal hemoglobin, increased O2 demand, decreased cardiopulmonary reserve, acuity and persistence of blood loss, hemodynamic stability
Causes of post-operative hypertension in a neonate
inaccurate measurement, pain, hypervolemia, hypoxemia, hypercarbia, bladder distension, increased intracranial pressure, undiagnosed coarctation of the aorta
differential and treatment for neonatal seizure
intracranial hemorrhage, hypoxic-ischemic encephalopathy, cerebral edema, hypoglycemia, hypocalcemia, sepsis, obstetric history of TORCH (toxoplasmosis, rubella, cytomegalovirus, herpes). tx: ensure adequate oxygenation, ventilation, and circulation, give barbiturate or benzodiazepine, order electrolytes, notify neonatologist
Common functional pituitary adenomas
prolactinoma, excessive ACTH (Cushing’s disease), excessive growth hormone (acromegaly), excessive TSH (hyperthyroidism)
How would you maintain general anesthesia if you are monitoring visual evoked potentials?
Visual evoked potentials monitor integrity of optic nerves, VEPs are extremely sensitive to inhalational and intravenous anesthetics so I would use a balanced technique with low concentration volatile agent, low concentration propofol infusion, and remifentanil infusion to minimize interference.
Cocaine injected into nasal mucosa and patient suddenly loses consciousness. What is going on and what would you do?
Local anesthetic systemic toxicity, high spinal, or cocaine induced dysrhythmia. I would intubate, give 100% O2, fluids, and medications to ensure adequate oxygenation, ventilation, and circulation. If this was LAST, then give benzodiazepine, consider intralipid infusion, and CPR if cardiovascular collapse
Causes of sudden drop in blood pressure during a transphenoidal resection of a pituitary adenoma in the sitting position
venous air embolism, massive hemorrhage, myocardial infarction, anaphylaxis, anesthetic overdose, cardiac dysrhythmia, tension pneumothorax. I would recheck BP, check for adequate oxygenation and ventilation by verifying proper ETT placement, auscultate the chest, look at EKG and etCO2, look at surgical field, consider TTE to confirm diagnosis.
What to do if there is a venous air embolism in a patient undergoing surgery in a sitting position
Ask surgeon to flood field with saline, deliver 100% O2, apply direct jugular venous compression to increase venous pressure at surgical site, provide hemodynamic support with fluids and vasopressors, try moving patient to trendelenberg and right side up position to reduce chance of air lock in the right ventricle
How would you extubate a patient who is high risk for difficult airway management
Place patient in slight reverse trendelenberg position, ensure adequate oxygenation, ventilation, and circulation, normothermic, fully reversed from paralysis, awake, alert, following commands, intact airway reflexes
Obese patient in PACU is obtunded and desaturating, what’s going on?DD
airway obstruction and apnea, overnarcotized, atelectasis, pulmonary edema, aspiration, inadequate reversal of paralysis, residual anesthesia, electrolyte abnormality, arrhythmia, MI, stroke
How is diabetes insipidus diagnosed and treated?
Polyuria, increased serum osmolality, decreased urine osmolality (urine specific gravity < 1.005), and urine osmolality increases wi
th administration of ADH. Tx: Central: Replace fluids and give DDAVP, Nephrogenic: Replace fluids and give thiazide or NSAIDs, consider amiloride (K-sparing diuretic) for lithium induced DI
what does normal PT and elevated PTT mean?
hemophilia A (VIII), hemophilia B (IX), hemophilia C(XI), von willebrand deficiency, low dose heparin, lupus anticoagulant
mechanism of desmopressin (DDAVP) in treating factor deficiency
DDAVP induces release of factor VIII and vWF from endothelial cells, is most effective when factor VIII levels are > 5%
To what level would you correct factor VIII preoperatively and how long do you continue giving factor VIII after surgery?
50-100% of normal, half life of factor VIII is about 6 hours, continue replacement for up to 2 weeks.
Pulmonary function tests that are best for pre-thoracotomy assessment
ppoFEV1 (respiratory mechanics) > 40% is low risk, ppoDLCO (lung parenchymal function) > 40% is low risk, VO2max (cardiopulmonary reserve) > 15 mL/kg/min is low risk. 2 flights = VO2max of 12. Extra info: PaO2 > 60 and PaCO2 < 45 are low risk
Normal PaO2 on room air can be estimated knowing patient’s age with what equation?
102 - (age / 3)
what are your anesthetic management goals for a particular case?
Preoperatively evaluate nature and severity of comorbidities, optimize cardiopulmonary functions, and plan for anticipated complications. Intraoperatively I want to maintain stable hemodynamics and oxygenation and ventilation, provide adequate level of anesthesia, secure the airway, reduce risk of complications, facilitate surgical exposure. Postoperatively I want to maintain ventilatory support, adequate pain control, and be vigilant for postoperative complications
Genetic mode of inheritance of malignant hyperthermia
Autosomal dominant with reduced penetrance and variable expression
how would you deliver jet ventilation?
Ensure adequate muscle relaxation and depth of anesthesia to prevent bronchospasm, initiate jet ventilation at low pressures until adequate chest rise and fall is noted, keeping in mind complications such as pneumothorax, subcutaneous emphysema, gastric distention, and aspiration of surgical debris.
Would you extubate a patient after an intraoperative airway fire?
No, inhalational injury can progress rapidly to life threatening airway obstruction, so I would give steroids, humidified oxygen, and monitor patient for at least 24 hours with continuous pulse oximetry and serial CXRs
Differential for hypoxia and high airway pressures in a patient still intubated postoperatively, and what would you do?
bronchospasm, pulmonary edema, kinked or plugged ETT, right mainstem intubation, pneumothorax. Tx: hand ventilate with 100% O2, suction ETT, auscultate lungs, ensure adequate placement of ETT, CXR, ABG
What is the pathophysiology and treatment of TRALI
Donor leukocyte antibodies activate neutrophils that lead to endothelial damage, capillary leakage, acute lung injury, pulmonary edema. Signs and symptoms include fever, tachycardia, dyspnea, cyanosis, hypotension. Tx: supportive, most patients recover within 96 hours.
Possible causes of decreased energy in a patient with pheochromocytoma
Catecholamine-induced cardiomyopathy or congestive heart failure, CVA, MI, acute renal failure, hypothyroidism, electrolyte abnormalities
Diagnosis of pheochromocytoma
Free metanephrines in plasma (most reliable test), plasma catecholamines, urinary catecholamines or metanephrines, urinary vanillymandelic acid.
Alpha blockade should be started how many weeks prior to pheochromocytoma surgery
2 weeks
Medications to avoid during pheochromocytoma surgery
Histamine releasing drugs (succinylcholine, morphine, atracurium), drugs causing significant hypertension (droperidol, metoclopramide, ephedrine), drugs that increase sympathetic activity (ketamine, atropine, pancuronium)
Why avoid inhalational induction in a patient with muscular dystrophy?
Volatile agents may induce rhabdomyolysis and hyperkalemia even in the absence of succinylcholine
what is considered a clinically significant reduction in SSEP or MEP signals?
50% decrease in amplitude or 10% increase in latency
what is hepatopulmonary syndrome?
triad of liver disease, hypoxemia, and intrapulmonary vascular dilation. symptoms of worsening dyspnea in the upright position. is an indication for liver transplantation
how would you determine if elevated creatinine level is secondary to hepatorenal syndrome?
Give a fluid challenge, if renal function improves, then likely pre-renal cause. Also check urine electrolytes, review medications.
what is the pathophysiology of hepatorenal syndrome?
Increased levels of vasodilators like nitric oxide lead to splanchnic arterial vasodilation, causing compensatory activation of the renin-angiotensin-aldosterone system, leading to systemic and renal vasoconstriction. Definitive treatment is liver transplantation.
Liver transplantation is contraindicated in patients with pulmonary artery pressures above what level?
mean PAP > 50 mmHg, Portopulmonary hypertension is defined as mean PAP > 25 mmHg
why is hepatic encephalopathy a concern?
Because it is associated with GI bleeding, infection, anemia, increased ICP. I would be careful giving any sedation drugs like benzodiazepines because they may exacerbate the encephalopathy
Reasons for hyperkalemia in the anhepatic phase of liver transplantation case
Acidosis causing K to move from intracellular to extracellular, high K in transfused rbcs, renal insufficiency due to hepatorenal syndrome
Proposed mechanisms for reperfusion syndrome, and how to manage it.
High K load from graft perfusate, release of vasoactive substances and metabolites from clamped off region. Correct acidosis, give calcium, give vasopressors or inotropes.
What toxicity can occur with nitroprusside infusion and how to treat?
Cyanide binds to tissue cytochrome oxidase (enzyme of the electron transport chain), impairing oxygen utilization, leading to metabolic acidosis, cardiac arrhythmias, and tachyphylaxis. Tx: 100% O2, give sodium thiosulfate or sodium nitrate or amyl nitrate which all remove cyanide ions from circulation
How would you evaluate and manage postop oliguria?
I would start with a focused H&P. From the history I would want to review the chart for fluids and meds given, the anesthetic record. From the physical I would assess the vital signs and check the foley catheter, check volume status. I would give a fluid bolus if appropriate, order serum and urine electrolytes, consider renal consult.
Risk factors and causes of perioperative acute renal failure
Risk factors: Advanced age, prolonged cross clamp time, cardiac disease, preexisting renal disease. Causes: renal ischemia, nephrotoxins, air embolization, activation of renin-angiotensin system.
Difference between narcotic abuse, dependence, addiction
Abuse: use that is detrimental to the individual or society
Dependence: physiologic state of adaptation to a substance that leads to withdrawal
Addiction: medical disease, abuse of addictive drug with loss of control and irrepressible craving
Why might a patient be difficult to wean off ventilator while getting TPN?
Patient on TPN may have hypophosphatemia or hypokalemia or hypermagnesemia, which leads to muscle weakness
During laparoscopic surgery, ABG shows PaCO2 is elevated, what would you do?
Review monitor (BP, EKG, etCO2, temperature), verify proper ETT placement, auscultate chest, review ABG. Look for signs of subcutaneous emphysema, tension pneumothorax, CO2 embolism, CHF, MH
Which antihypertensive meds to give during pheochromocytoma surgery
Use rapid onset and short acting meds such as esmolol, nitroglycerine, nitroprusside, nicardipine, labetalol, and phentolamine
Signs of elevated intracranial pressure
headache, nausea, altered mental status, papilledema, Cushing’s triad (HTN, bradycardia, irregular respirations) Cushing causes gastric ulcer so risk of bleeding and aspiration (tx: PPI)
During cerebral aneurysm surgery, ST changes on EKG can be a sign of what?
subarachnoid hemorrhage, myocardial ischemia. Check CKMB and troponins to differentiate.
How do you differentiate SIADH (syndrome of inappropriate antidiuretic hormone) and CSWS (cerebral salt wasting syndrome)?
SIADH is euvolemic and urine sodium levels are < 100 meq/L while CSWS is hypovolemic and urine sodium levels > 100 meq/L. Treatment for SIADH is fluid restriction and diuresis, while treatment for CSWS is fluid replacement
What is ankle brachial index (ABI) ?
Ratio of ankle to brachial systolic pressures using doppler, claudication is associated with ABI < 0.9. Rest pain at ABI < 0.5, ulceration at ABI < 0.25
Differential for delayed emergence specifically after a craniotomy
Hematoma formation, tension pneumocephalus, cerebral edema, cerebral ischemia, hypoxia, hypercarbia, seizure, obstructive hydrocephalus
Anesthetic concerns for a cystic fibrosis patient? Preop labs?
Concerns for decreased pulmonary function such as of hypoxia, bronchospasm, pneumothorax, postoperative respiratory failure, pHTN leading to right heart failure. Also hepatic, pancreatic, and GI involvement leading to coagulopathy, pseudocholinesterase deficiency, diabetes, electrolyte abnormalities. I would order CBC, BMP, coags, ABG, possibly CXR, EKG, PFTS, TTE, LFTs
Pathophysiology of cystic fibrosis
Recessive genetic disorder with a defective cystic fibrosis transmembrane conductance regulator (CFTR) gene leading to abnormal NaCl movement that causes thick secretions that affect lungs, pancreas, liver, GI: mucous plugging, inflammation, chronic infections, emphysema, hypoxemia, cor pulmonale, cardiomegaly, hepatomegaly, respiratory failure, malnutrition, diabetes, coagulopathy, decreased cholinesterase.
Treatment for cystic fibrosis
Prevention and control of pulmonary infections, antibiotics, physical therapy, enzyme replacement, adequate nutrition
Risk factors for emergence delirium and methods to prevent it
Preop anxiety, young age, postop pain, less soluble volatile agents like sevo and des, prolonged surgery, patient temperament. Reduce preop anxiety, good pain control, sedative like midazolam propofol or dexmedetomidine
Treatment for extrapyramidal symptoms caused by metoclopramide
Ensure adequate oxygenation and ventilation, give diphenhydramine or benztropine (anticholinergics)
What causes a phase 2 blockade with use of succinylcholine?
Excessive doses, prolonged infusions, or abnormal metabolism of succinylcholine leading to larger dose of succinylcholine reaching the neuromuscular junction.
What does it mean when troponin is positive but Ck-mb is negative?
MI occurred more than 2-3 days ago. CK-MB is elevated 4-6 hours after MI and returns to baseline within 2-3 days. Troponin is elevated 2-6 hours after MI and returns to baseline after 7-10 days.
ST segment depression can be caused by what?
NSTEMI, subendocardial ischemia, digoxin use, hypokalemia
Therapeutic levels of digoxin, factors that potentiate digoxin toxicity, treatment for digoxin toxicity?
0.5-2.0 ng/mL. Hypokalemia, hypomagnesemia, and hypercalcemia can potentiate digoxin toxicity (nausea, blood stools, blurred vision, confusion, muscle weakness, ventricular arrhythmias). Tx: check digoxin level, digibind is antidote (10-20 vials), supportive care
Most likely cause of coagulopathy following cardiopulmonary bypass?
Platelet dysfunction. Differential includes thrombocytopenia, dilutional coagulopathy, DIC, hypothermia, fibrinolysis
What is the American academy of dermatology recommended maximum dose of lidocaine for liposuction? And what can you do to reduce risk of local anesthetic systemic toxicity?
55 mg/kg. Use diluted solution with epinephrine, limit volume of fat removal to 3000 mL, have intralipid available
Diagnosis of CRPS
Clinical diagnosis with inciting event, followed by burning pain, allodynia, hyperalgesia, cyanosis, edema, sweating, glossy skin, hair loss, osteoporosis, stiff joints. Type 1 is nonspecific area of injury while type 2 is specific nerve injury
Treatment for CRPS
Opioids (CRPS doesn’t respond well to opioids), gabapentin, antidepressants, physical therapy, sympathetic nerve block, ketamine. Prognosis: most patients are still in pain with some degree of functional dysfunction after one year, even with intensive therapy.
Causes of premature ventricular contractions (PVCs)
Increased levels of adrenaline (caffeine, tobacco, anxiety, exercise), epinephrine, hypoxia, cardiac ischemia, electrolyte abnormalities, anesthesia induced cardiac depression.
Intralipid dosing
20% lipid solution. 1.5 mL/kg bolus over 1 minute, then infusion rate of 0.25 mL/kg/min. Repeat bolus and increase infusion rate if cardiovascular instability persists. Max dose of intralipid is 8 mL/kg bolus.
What is aplastic crisis?
Decreased RBC production caused bone marrow suppression secondary to infection or folate deficiency.
Decision to give a blood transfusion is based on what criteria?
Patient comorbidities (CAD, sickle cell, coagulation deficiencies), current surgical hemostasis and likelihood of continued blood loss, hemodynamic stability, signs of decreased tissue perfusion (lactic acid, mixed venous oxygen saturation, pulse oximetry, etco2, circulation, cap refill)
Pathophysiology of bone cement implantation syndrome
Hardening and expansion of cement leads to increased intramedullary pressure and embolization of bone debris leading to pulmonary hypertension, hypotension, hypoxia, dysrhythmias, cardiac arrest. Also release of cytokines during reaming lead to microthrombi formation.
Why not initiate beta blockers on day of surgery and how many days prior to surgery should they be started?
Initiation of beta blockers without careful titration may increase overall morbidity and mortality secondary to hypotension, bradycardia, stroke, and death. Ideally begin beta blockers 2-7 days before surgery, but even better to give 6-8 weeks to allow HR to decrease close to 60
What is the pathophysiology of autonomic hyperreflexia?
Stimuli below the level of spinal cord injury results in reflex sympathetic discharge without inhibition from higher central nervous system centers, leading to vasoconstriction below level and reflex vasodilation above level that is insufficient to prevent systemic hypertension.
What are the subsequent complications of autonomic hyperreflexia if it is not treated?
MI, intracranial hemorrhage, seizure, dysrhythmias, pulmonary edema
Differential for no twitches of peripheral nerve stimulator at the end of a case when succinylcholine and a nondepolarizing agent given
Drug error, defective nerve stimulator, pseudocholinesterase deficiency, electrolyte abnormality, hypothermia, acidosis, hypercarbia, aminoglycoside administration, neuromuscular disease such as myasthenia gravis, eaton lambert syndrome, ALS.
How to differentiate between myasthenia or cholinergic crisis?
Both have muscle weakness, salivation, and sweating. Myasthenia has mydriasis (large pupils) and improved strength with edrophonium. Cholinergic crisis has miosis (small pupils) and increased weakness with edrophonium.
What is hypertrophic obstructive cardiomyopathy?
Genetic condition characterized by left ventricular hypertrophy, dynamic left ventricular outflow tract obstruction, systolic anterior movement of the mitral valve, diastolic dysfunction, myocardial ischemia, dysrhythmias leading to sudden death.
Pyloric stenosis diagnosis
Ultrasound or X-ray with barium
Why is rehydration important in correcting metabolic alkalosis caused by emesis?
It’s important because dehydration and hyponatremia causes kidneys to conserve sodium which leads to reabsorption of bicarbonate, which worsens the metabolic alkalosis
Anesthetic considerations for obstructive sleep apnea (OSA)
Coexisting comorbidities such as HTN, CAD, pHTN, arrhythmias, right heart failure. As well as airway difficulties, sensitivity to narcotics, extubation criteria, postoperative pain control, ASA guidelines recommend monitoring OSA patients 3 hours longer than non-OSA patients and 7 hours after last episode of airway obstruction or hypoxemia.
Causes of hypertension in a young adult
Pain, hypoxia, hypercarbia, anxiety, illicit drug use, hyperthyroidism, hypercalcemia, pheochromocytoma, coarctation of the aorta, elevated ICP, polycystic kidney disease
Why would a surgeon ask for a lumbar drain for a cerebral aneurysm surgery?
To treat hydrocephalus, reduce brain bulk to facilitate access to aneurysm, control intracranial pressure, and may reduce symptomatic vasospasm
What things can you do if cerebral aneurysm ruptures during clipping procedure?
Induce hypotension to reduce blood loss, manual pressure on ipsilateral carotid, consider hypothermic arrest
Is it necessary to get a serum sodium level for an ESRD patient?
Yes, because renal failure can lead to hyponatremia which can cause cerebral edema, seizures, lethargy, mental status changes, muscle weakness
what is systemic lupus erythematosus (SLE)?
autoimmune disease causing systemic chronic inflammation (ie. vasculitis, which can increase risk of intracerebral hemorrhage) and tissue damage. antinuclear antibodies (ANA), malar rash, nephritis, arthritis, pericarditis, seizures, peripheral neuropathy, thrombocytopenia, hemolytic anemia, coagulation factor deficiency, antiphospholipid antibodies (prolonged PTT) causing thromboembolic events like fetal demise. medications: steroids, immunosuppresants, anticoagulants, NSAIDS
What can you do to attenuate the hypotension caused by rapid administration of vancomycin?
Vancomycin administration leads to histamine release causing drop in systemic vascular resistance, so you can give antihistamines prior to giving vancomycin
what type of acute aortic dissection requires immediate surgical repair?
acute aortic dissection involving the ascending aorta; proximal propagation can lead to aortic insufficiency, tamponade, and coronary artery dissection.
what hemodynamic changes occur with placement of an aortic cross-clamp?
Increased afterload leading to increase in blood pressure, left ventricular wall tension, central venous pressure. Decrease in ejection fraction, cardiac output, renal blood flow, and distal perfusion pressure. HR and MAP usually elevated unless underlying poor ejection fraction can lead to hypotension and bradycardia so do not start vasodilators prior to cross clamp
how does hypothermia cause coagulopathy?
Mild hypothermia (33-35C) causes defects in platelet aggregation and adhesion. More severe hypothermia (> 33C) also causes abnormal coagulation enzyme activity.
How does thromboelastography (TEG) measure coagulation?
TEG measures viscoelastic properties of blood during induced clot formation, clinically identifying coagulation factor activity (R time, time to initial clot formation), fibrin formation (K time and alpha angle, speed of clot formation), platelet function/concentration (MA, clot strength), fibrinolysis activity (LY30, degree of fibrinolysis).
Increased R time -> give FFP
Decreased alpha angle -> give cryoprecipitate
Decreased MA -> give platelets, consider DDAVP
Decreased LY30 -> give tranexamic acid
Treatment for a bleeding patient with uremic platelet dysfunction
Desmopressin (DDAVP), which induces release of vWF factor and factor VIII from endothelial cells that leads to improvement of platelet adhesion and aggregation. Also consider giving EPO, cryoprecipitate, platelets, and performing dialysis to remove uremic acid.
How would you manage a patient who is taking lithium?
Preoperatively I would evaluate for signs of toxicity like muscle weakness, seizures, polyuria, widened QRS, AV block, hypotension. Check most recent lithium level and EKG. Intraoperatively, I would closely monitor neuromuscular blockade and anesthetic depth because lithium prolongs paralysis and reduces MAC. Postoperatively, I would ensure patient is fully awake and meeting all extubation criteria.
How would to evaluate whether a hyperthyroidism patient’s condition is controlled adequately?
First perform history and physical looking for signs of hyperthyroidism such as diarrhea, warm moist skin, heat intolerance, cardiac arrhythmias, fatigue, muscle weakness, fine tremor. Consider ordering TSH, free T3 and T4 levels.
What conditions cause thyroxine binding globulin (TBG) to increase, leading to elevated total T4 levels?
Pregnancy, birth control pills, acute liver disease
Differential diagnosis for inspiratory stridor, restlessness, and tingling around mouth 3 hours after total thyroidectomy
Hypocalcemia secondary to removal of parathyroid glands (typically 24-96 hours after surgery), hematoma, post-intubation croup, residual neuromuscular blockade, recurrent laryngeal nerve injury, hypoxia, hypercarbia, hypoglycemia.
Why would you not administer aspirin in a patient with thyrotoxicosis?
aspirin displaces thyroid hormones from binding proteins which would exacerbate the condition
How to distinguish between neuroleptic malignant syndrome (NMS) and malignant hyperthermia (MH)?
1) NMS exhibits slower progression to critical temperature and multi organ failure
2) Non depolarizing muscle relaxants will produce flaccid paralysis in NMS patients. Difficult to differentiate, so initiate dantrolene, active cooling, consider bromocriptine (dopamine agonist)
What are your concerns and evaluation of a patient with elevated hypertension prior to surgery?
Concerns with increased perioperative risk of hemodynamic lability, myocardial ischemia, dysrhythmias, congestive heart failure, stroke, renal insufficiency, and other end-organ ischemia. I would perform a focused HandP to identify end organ damage by asking about baseline BP, medications, symptoms of angina and dyspnea, exercise tolerance, neuro symptoms, assess other vital signs, volume status, listen to heart and lungs, consider obtaining an EKG (LVH), CXR, electrolytes, BUN/Cr. Stage 1 (140/90), Stage 2 (160/100), Stage 3 (180/110), would prefer to delay surgery 6-8 wks if stage 3 or stage 1/2 with end-organ damage.
Signs of hypervolemia and hypovolemia
Hypervolemia: HTN, pulmonary edema, peripheral edema, JVD
Hypovolemia: hypotension, tachycardia, dry mucous membranes, orthostasis
Differential for sudden drop in blood pressure (hypotension) intraoperatively
Monitor error, decreased contractility, rate/rhythm abnormality, MI, CHF, valvular disease, hypoxia, hypercarbia, acidosis, electrolyte abnormality (hyperkalemia, hypocalcemia, hyponatremia, hypoglycemia), hypovolemia, blood loss, sepsis, anaphylaxis, anesthetic overdose, tension pneumothorax, pulmonary embolism (clot, air, fat, amniotic), tamponade, hypothermia
Most common cause of post-operative coagulopathy
Platelet dysfunction caused by uremia, hypothermia, severe anemia, or drug effect. Differential includes residual heparin effect, inadequate surgical hemostasis, metabolic acidosis, thrombocytopenia, DIC. I would check platelet count, INR, PTT, fibrinogen, CBC, possibly TEG.
Why would you not recommend treating patient’s oliguria with dopamine?
Dopamine does not reliably improve renal function, in addition, the inotropic effects may increase myocardial oxygen demand and increase risk of MI. May consider fenoldopam which is a D1-selective agonist.
What are anesthetic considerations for a patient with rheumatoid arthritis?
Airway: cervical stiffness, TMJ stiffness, consider awake fiberoptic intubation
Cardiac: pericarditis, arrhythmias, myocardial ischemia, valvular disease
Pulmonary: fibrosis, pleural effusions
GI: ulcers from anti-RA meds
Renal: dysfunction from anti-RA meds
Neuro: peripheral neuropathy, joint deformity
What are drug treatments of rheumatoid arthritis and how do they affect anesthetic management?
NSAIDS: renal insufficiency (vasoconstriction of afferent arteriole leading to decreased renal blood flow)p, platelet dysfunction, GI ulcers
corticosteroids: need for stress dose
DMARDs (disease modifying anti-rheumatic drugs): increased risk of infection
what’s the difference between type and screen and type and cross?
type and screen mixes recipient plasma with panel of commercial RBCs while type and cross mixes recipient plasma with the donor RBCs
what would you do if a hemolytic transfusion reaction occurs?
stop transfusion, 100% FiO2, treat hypotension with fluids and vasopressors, recheck prbc unit number, notify blood bank, consider diuretic and sodium bicarb to prevent renal injury
What is the pathogenesis of acute intermittent porphyria?
Deficiency of one of the enzymes in the heme biosynthesis pathway leads to overproduction of porphyrins. Various drugs or anemia can induce AIP, causing severe abdominal pain, nausea, muscle weakness, respiratory failure, peripheral neuropathy, electrolyte abnormalities, psychiatric disturbance
what can you do to reduce the risk of acute intermittent porphyria and how would you treat it?
I would avoid fasting, dehydration, stress, infection, anemia, certain drugs like ketorolac and etomidate. To treat, I would ensure adequate oxygenation, ventilation, hydration, analgesia, anxiolysis, give carbs, give anti-emetics, correct any electrolyte abnormalities, give hematin (a porphyrin).
What equipment is required for a non-operating room conscious sedation room?
2 sources of oxygen, ASA standard monitors (BP, pulse ox, EKG, etCO2, temp), airway equipment, emergency meds, crash cart, flashlight, and CPR-certified personnel
what are the risk factors for late stent thrombosis following placement of a drug eluting stent (DES)?
Premature discontinuation of antiplatelet therapy, multiple lesions, long stents, overlapping stents, low EF, advanced age, DM, renal failure
What’s the only definitive treatment for HELLP syndrome?
Delivery of baby
How do oxytocin, methergine, and hemabate work?
They increase intracellular calcium levels to cause contraction of myometrial smooth muscles. oxytocin (hormone) methergine (serotonin/dopamine receptors) hemabate (prostaglandin)
How does PEEP work?
PEEP recruits atelectatic fluid-filled alveoli to decrease intrapulmonary shunting and increase compliance. It moves fluid to areas where gas exchange is not taking place
How can PaO2 can be estimated from FiO2?
PaO2 = FiO2 times 5
What is pseudotumor cerebri?
Intracranial hypertension (usually > 20 mmHg) without a mass lesion. It’s associated with headaches, papilledema, visual disturbances.
What’s the minimal criteria for undergoing caffeine halothane contracture testing?
At least 7 years old and 20kg
In general, what are your goals for induction of general anesthesia
I want to maintain hemodynamic stability while safely securing the airway and at the same time, avoid aspiration, hypoxia, hypercarbia, bronchospasm.
Why would you want to place a pulmonary artery catheter (PA catheter) ?
To help optimize hemodynamic management by knowing the cardiac output, mixed venous O2 saturation, wedge pressure, pulmonary artery pressures, and ability to calculate SVR and PVR (eg. low EF, severe valvular disease, pHTN, severe hemodynamic instability with unclear etiology)
How does severe anemia cause decrease in systemic vascular resistance?
Severe anemia leads to less viscosity which means decrease in vascular resistance
In general, what is your extubation criteria?
Patient is awake, alert, following commands, able to protect airway, normothermic, hemodynamically stable, oxygenating and ventilating adequately, muscle relaxant reversed, no edema or active bleeding (airway, pulmonary) Objective criteria (RR< 30, ABG on 40% FiO2 with pH>7.3 and PaO2 > 60mmHg and PaCO2<55, TV>4-6mL/kg, NIF>20cm H20, RSBI<103, FVC>10-15ml/kg, adequate hgb)
Which inhaled anesthetic is theoretically preferred for craniotomies and why?
Isoflurane because it causes burst suppressio
n that theoretically is neuroprotective.
What is the limit to how low PaCO2 should go to help decrease ICP?
25 mmHg, because if it gets lower, it can induce cerebral ischemia caused by decrease in cerebral blood flow and leftward shift of the oxyhemoglobin dissociation curve
In general, what is your intubation criteria?
Patient is unstable, unable to protect his airway 2/2 neurological injury or trauma or agitation, has increased work of breathing or fatigue, respiratory rate > 35, PaCO2 > 55, PaO2 < 60 on FiO2 50%
In general, what are causes of hypoxemia?
Decreased delivery of oxygen (machine failure, disconnection in the circuit), hypoventilation (esophageal intubation, ETT kink or ruptured cuff, respiratory depression, ventilator failure), V/Q mismatch (mainstem intubation, bronchospasm, mucous plug, pulmonary embolism, pneumothorax, atelectasis), intracardiac shunting, impaired diffusion (pulmonary edema, aspiration, COPD, ARDS)
In general, what are causes of hypercarbia?
Increased production of CO2 (MH, tourniquet release, cross-clamp release, sepsis, thyrotoxicosis, fever), decreased removal of CO2 (hypoventilation, pneumothorax, mainstem bronchial intubation, airway obstruction, increased dead space), laparoscopic surgery (subcutaneous emphysema, CO2 embolism), sodium bicarb administration, rebreathing of CO2 (faulty ventilator valves, low fresh gas flows, exhausted CO2 absorber)
In general, what are causes of hypotension?
hypovolemia, cardiac (decreased contractility, rate/rhythm abnormality, MI, CHF, valvular disease, tamponade), pulmonary (hypoxia, hypercarbia, tension pneumothorax), embolism (clot, air, fat, amniotic), electrolyte abnormality (hypocalcemia, hypoglycemia, hypermagnesemia), anaphylaxis, adrenal suppression, sepsis, hypothermia, iatrogenic (deep anesthesia, sympathetic block, venodilation, laparascopy)
In general, what are causes of hypertension?
Hypervolemia, pulmonary (hypoxia, hypercarbia, OSA), pain, anxiety, neuro (increased ICP, hyperreflexia), renal (PCKD, renovascular disease), endocrine (pheo, thyrotoxicosis), drugs (vasopressors, steroids, withdrawal), electrolyte abnormality (hypercalcemia), inadequate depth of anesthesia, MH, bladder distension, tourniquet pain
differential and treatment and prevention of cold and pale hand with an arterial line
Raynaud’s disease, ischemia 2/2 to arterial line, diabetic neuropathy, peripheral vascular disease. Evaluate patient by assessing cap refill, collateral pulses, optimize hemodynamics, warm the hand, consider stellate ganglion block which may improve blood flow, consult vascular surgeon to evaluate for possible embolectomy. To prevent this complication, I would avoid multiple sticks, use smaller catheter size, avoid prolonged hypotension and high doses of vasoconstrictors, monitor pulse oximetry, and limit cannulation time.
How would you evaluate a burn and trauma patient:
First assess ABCs, assess volume status, look for fractures and bleeding, insert foley catheter and perform a rectal exam. Finally order CXR, EKG, CBC, ABG with cooximetry, electrolytes, and LFTs, head and neck CT if head and neck trauma suspected.
Why not administer colloids in a burn patient?
There is no good data to suggest that colloids improve outcome, colloids may worsen third-spacing from the leaky capillaries caused by a burn
How would you evaluate the airway of a burn patient?
Look at extent of burn around the face, singed nasal hair, swelling around airway, exam mouth and tongue, and if there is history of difficult intubation
Why avoid halothane?
It produces the most myocardial depression, most dysrhythmogenic, and has risk of hepatotoxicity
When would you want to get a stress test?
If surgery was not emergent, and if there were active cardiac conditions like unstable coronary syndrome (recent MI, unstable angina), significant arrhythmias, severe valvular disease, or decompensated CHF
If patient is not already on a beta blocker, what is the other class I indication for giving a beta blocker intraoperatively?
If the patient is undergoing vascular surgery and is at high cardiac risk
What is your endpoint to treating tachycardia in a high risk cardiac patient?
Ideally keep the heart rate in the 60s to decrease myocardial oxygen demand and increase myocardial oxygen delivery, however, I would carefully titrate to avoid excessive hypotension.
How would you perform topical anesthesia for an awake nasal fiberoptic intubation?
I would topicalize the nose with viscous lidocaine jelly mixed with phenylephrine, aerosolized lidocaine for the oropharynx, and perform superior laryngeal and transtracheal blocks for the regions above and below the vocal cords
Why would you not use cocaine to topicalize the airway for awake intubation?
I would not use it due to potential for systemic absorption, leading to hypertension and tachycardia
In the middle of a case, peak pressures increase from 15 to 30, what do you think is going on and what would you do?
It could be a variety of reasons, such as bronchospasm, mucus plug, kink in the ETT or circuit, mainstem intubation, pneumothorax, patient spontaneously breathing, aspiration, increased intra-abdominal pressure, malignant hyperthermia, or machine failure. 100% O2, look at my monitors for adequate oxygenation and circulation, then hand ventilate to feel the compliance, auscultate the chest, looking for symmetric chest rise
How does albuterol treat bronchospasm?
It activates beta 2 receptors on bronchial smooth muscle cells, causing increase in intracellular cAMP levels, leading to smooth muscle relaxation.
What would you do if blood pressure suddenly drops to 60/40 intraoperatively? (severe hypotension)
100% FiO2 high flows, cycle BP measurement, open up IV fluids, temporize with vasopressors, turn down my anesthetic agent, look at my monitors, specifically the etCO2, HR, rhythm, saturation, check for a pulse, and see what’s going on surgically. Look at bilateral chest rise, check ETT, auscultate breath sounds, hand ventilate to feel for compliance while continuing to evaluate.
How can a PA catheter help evaluate the cause of hypotension?
If wedge pressure and cardiac output are low, it suggests hypovolemia. If wedge pressure is high and cardiac output is low, it suggests ventricular noncompliance from myocardial dysfunction or elevated airway pressures from bronchospasm. If cardiac output is high, it suggests possible low SVR.
What are causes of anemia in a patient with chronic alcohol abuse?
cirrhosis leading to coagulopathy, GI bleeding, esophageal varices. also malnutrition like folate deficiency leading to megaloblastic anemia
In acute respiratory acidosis, the pH drops how much for every 10 mm increase in PaCO2?
pH drops by 0.08, so if PaCO2 is 50 mmHg, and pH is 7.32, then this is an acute respiratory acidosis
Which vocal cord muscle is not innervated by the recurrent laryngeal nerve?
cricothyroid muscle
Which vocal cord muscle is the only one that causes abduction of the vocal cords?
posterior cricoarytenoid muscle
What are causes of intraoperative supraventricular tachycardia?
sympathetic stimulation, MI, hypoxia, hypercarbia, hypotension, hyperthermia, electrolyte abnormalities like K, tamponade, light anesthesia
After an intraoperative cardiac arrest, patient has return of spontaneous circulation, do you continue with the case?
If the patient were stable and causes of the cardiac arrest could be assessed and treated, I would continue with the case. If the patient were unstable and the surgery interfered with assessing and treating the cardiac arrest, I would ask the surgeon to stop.
How long after alcohol abstinence does withdrawal symptoms begin, and how would you prepare for them?
Withdrawal can occur within 6 hours of abstinence and delirium tremens can occur 3-5 days after abstinence. Effective prophylaxis can be achieved with a long half life benzodiazepine like lorazepam. Treatment with vitamin supplementation and beta blockers may be useful as well.
What are the advantages and disadvantages of weaning from a T-piece?
The advantage is that it is simple and avoids mechanical ventilation. The disadvantage is that there is risk of hypoventilation, patient fatigue, hypoxia, and hypercarbia.
What are the advantages and disadvantages of weaning from SIMV?
The advantage is that with ventilatory support, there is less likelihood of hypoxia, hypercarbia, and atelectasis. The disadvantage is possible barotrauma and hypotension from positive pressure ventilation.
Complications associated with intraosseous access?
Compartment syndrome, tissue necrosis, infection
What options do you have to minimize blood transfusions?
Preoperative autologous blood donation, acute normovolemic hemodilution, cell saver, antifibrinolytic therapy, avoid hypothermia
How does venous air embolism cause decrease in lung compliance?
Air bubbles can cause an inflammatory response, leading to bronchospasm
Signs and symptoms of autonomic neuropathy?
Early satiety, bloating, postural hypotension, peripheral neuropathy
What is STOP-BANG screening?
Identify risk of undiagnosed OSA with 3 or more criteria associated with high risk of OSA. S-snoring T-tiredness O-observed apnea P-pressure (HTN) B-BMI>35, A-age>50, N-neck > 40 cm, G-gender (male)
How would you induce a COPD, GERD, pheochromocytoma patient?
I would ensure adequate airway equipment, monitors, and IV access, appropriate volume replacement, aspiration prophylaxis, bronchodilator therapy, adequate preoxygenation, apply cricoid pressure, place in reverse trendelenberg, give fentanyl and lidocaine, assuming reassuring airway, perform RSI with propofol and rocuronium, and secure the airway.
what’s the half life of epinephrine and norepinephrine?
1-2 minutes
what problems can hypertension cause during pregnancy?
fetal growth restriction, preterm delivery, placental abruption,
Why would you not place a pulmonary artery catheter (PA catheter)?
Although a PA catheter may be helpful to optimize hemodynamics by knowing the cardiac output, PA pressures, mixed venous saturation, and SVR, assuming this patient doesn’t have a low EF, significant valvular disease, or severe pHTN, then the risks of placing the PA catheter outweigh the benefits, especially if it doesn’t change my management or the outcome.
Minimal acceptable systolic blood pressure for pediatric patient under 10 yrs old.
SBP > 70 + 2 x age, term neonate SBP > 60
If surgeon places a temporary clip for a cerebral aneurysm repair, how will you manage the blood pressure?
I would maintain a higher than normal blood pressure to support collateral flow of blood.
What are strategies to provide neuroprotection during a crani or aneurysm case?
Reduce CMRO2 using propofol, utilizing neuromonitoring like SSEP and EEG, ensuring brain relaxation like diuretics and head up and CSF drainage, allowing mild hypothermia (32-34C)
If a patient is severely hypertensive for an emergent case, how would you determine the lower limits of tolerable blood pressure?
I would first want to know what the patient’s baseline blood pressure is. If I can’t get that information, then I would gradually lower the BP while assessing the patient’s mental status and signs of myocardial ischemia
What are risks to having a surgeon place a shunt during a carotid endarterectomy?
Embolization, artery dissection, increase in blood loss
Why does it not matter what the level of growth hormone is in an acromegaly patient?
Because levels fluctuate over the course of a day, so I am more concerned about the effects of high levels of growth hormone.
How do you differentiate between epiglottitis and croup?
Epiglottitis is in children 3-6 yrs old, associated with a fever and more toxic presentation. Croup is in children 6 mo-3 years, associated with a viral illness and barking cough.
When a patient complains of pain or something else general, you are called to evaluate.
I would determine the type, location, quality, and severity of the pain, what made it better or worse, ask whether it’s new or old, any associated symptoms, and what treatment has been done so far. The differential includes…
How would you provide anesthesia for a post-CABG patient with suspected tamponade in the ICU?
A patient with severe tamponade is extremely preload and afterload dependent so I would give fluids, vasopressors, maintain spontaneous ventilation with ketamine, if positive pressure ventilation became necessary, then very small tidal volumes.
What are advantages of neuraxial technique (epidural) for cesarean section (c-section)?
Neuraxial technique provides good pain control without using narcotics and can decrease circulating catecholamines, thus improving uteroplacental blood flow. Avoiding general anesthesia which has risksFvasc of neonatal depression, aspiration, airway compromise from edema, acute blood pressure elevation during laryngoscopy leading to cerebral hemorrhage and pulmonary edema.
What does a S3 heart sound mean and when does it occur in the cardiac cycle?
It means increased volume of blood within the ventricle during early diastole. It can be benign in young, athletes, and pregnancy. Or pathologic cause is CHF.
What does a S4 heart sound mean and when does it occur in the cardiac cycle?
Pathologic sign when atrial contraction forces blood into stiff or hypertrophic ventricle at the end of diastole.
What are causes of stridor and how would you evaluate?
bilateral vocal cord paralysis, obstruction from infection (croup, epiglottitis) or foreign object or mass, airway edema (trauma, burn), laryngomalacia or tracheomalacia. Rule out need for emergent intubation, then if intubation can be delayed, give O2 by facemask, head up, nebulized racemic epi, IV decadron while obtaining thorough history and physical, watching the HR, RR, oxygenation, ventilation, and level of consciousness, get CXR, ABG, flexible bronchoscopy, consider ENT consult.
What are signs and symptoms of hypoglycemia?
hypotension, irritability, arrhythmias, seizures, cognitive defects, respiratory failure, death
why give dextrose IV solution during surgery for a diabetic patient and what amount should be given?
Dextrose is given to prevent hypoglycemia, ketosis, and protein breakdown during surgery. Should give 5 grams/hour of glucose for basal energy requirements, this is equal to dextrose 5% solution given at 100 mL/hour.
what’s the dose of mannitol?
0.25-1.0 g/kg over 15-30 min
What are clinical symptoms of hypokalemia?
fatigue, muscle weakness, flattening of T waves, ST depression, prominent U waves, atrial fibrillation, PVCs, other arrhythmias. Tx: Check magnesium level because hypomagnesemia can inhibit replacement of K+.
What are the upper and lower limits for sodium and potassium imbalances to proceed with an elective case?
Na 130 - 150
K 2.6 - 5.9
What’s the definition of hypocalcemia and hypercalcemia in terms of ionized calcium levels?
hypocalcemia < 1.0 mmol/L
hypercalcemia > 1.5 mmol/L
Treatment options for tracheomalacia
If emergent re-intubation is not required, conservative treatment with CPAP, humidified air, chest PT, respiratory exercises.
How can you differentiate peroneal nerve injury from lumbosacral L4-5 injury?
Both have foot drop, but with peroneal injury, plantar flexion and inversion are preserved
Contraindications to cell saver
Tumor cells, amniotic fluid, fecal contamination
Why not use ketamine for induction for a patient with CAD?
Ketamine would not be my agent of choice because it is a sympathomimetic that can cause hypertension and tachycardia which can result in unfavorable supply to demand ratio for myocardial perfusion. Instead, I would use…
What physiological derangements are common with cross clamp?
Cross clamp results in sudden increase in afterload leading to extreme hypertension proximal to the clamp and a decrease in perfusion distal to the clamp, importantly to the kidneys and spinal cord.
What steps will you take to reduce risk of renal failure from cross clamp?
I will 1) minimize cross clamp time to < 30 min, 2) optimize intravascular volume with methods such as monitoring urine output
What steps can you take to reduce risk of spinal cord injury from cross clamp?
I can 1) use neuromonitoring like SSEP/MEP to identify decrease in spinal cord perfusion leading to ischemia and decreased signals, 2) minimize cross clamp time, 3) sequential aortic clamping, 4) reimplantation of segmental vessels, 5) bypass, 6) CSF drainage via lumbar drain, 7) perform hypothermic circulatory arrest. All of these are methods, along with maintaining stable hemodynamics and judicious hydration prior to clamp placement
How can you minimize the drop in blood pressure with release of a cross clamp?
I can 1) ensure adequate intravascular volume 2) use vasopressors like phenylephrine and norepinephrine prior to unclamping 3) ask surgeon to slowly release clamp and reapply as necessary
What are complications from use of hetastarch?
Hetastarch can cause coagulopathy, anaphylactoid reaction, and acute renal failure.
Cardiac lesions that are contraindications for surgery in sitting position
PFO/ASD/VSD, anything that can cause paradoxical air embolism. Lesions like valvular stenosis and mitral valve prolapse which are very preload dependent are relative contraindications
Signs and symptoms of elevated ICP
altered mental status, dilated pupils, papilledema, posturing, nausea/vomiting, headache
Hemodynamic responses to brain stem stimulation in the posterior fossa, and what to do?
Abrupt and transient hypertension and bradycardia or hypertension and tachycardia, or bradycardia and hypotension, and ventricular dysrhythmias. Monitor EKG and blood pressure, alert surgeon
How do you test precordial doppler prior to surgery?
Inject 10 cc of agitated saline or 5 cc of CO2
Young healthy male develops severe hypotension and bradycardia after a spinal that is not high
Bezold-Jarisch reflex, tx: epinephrine for extreme bradycardia
why is acute hypokalemia worse than chronic hypokalemia?
Higher risk of cardiac dysrhythmias, surgery should be postponed
how does potassium levels affect pacemaker capture?
Hyperkalemia elevates resting membrane potential (RMP), thus causing inappropriate firing. Hypokalemia lowers RMP, thus making threshold more difficult for pacemaker to capture.
How is Pickwikian syndrome (obesity hypoventilation syndrome) diagnosed?
1) BMI > 30
2) PaCO2 > 45
3) No alternative explanation for hypoventilation
Challenges of using TIVA technique
Inability to measure anesthetic depth like with inhaled anesthetics, more fluid given, IV infiltration or other problems with IV can disrupt anesthesia administration.
Prominent u waves seen intraop. What’s the cause and what will you do?
Concerned for hypokalemia. Check potassium level and replete as needed. Other causes include bradycardia, hypocalcemia, digoxin use, LVH, hypothermia
Causes of oliguria following renal transplant
Graft failure, toxic injury, vessel occlusion, hypovolemia, obstruction of bladder or foley
Why isn’t dantrolene used prophylactically treat malignant hyperthermia?
It is not indicated, it masks the early signs of malignant hyperthermia so it can delay treatment, there are side effects: it acts like a muscle relaxant, potentiates neuromuscular blockade, increases risk of aspiration.
Reasons to do GA for c-section
Patient refusal to regional, absolute contraindication to regional like patient on anticoagulants or infection at the site, critical valvular stenosis, failed regional technique, emergency situations during which mother or baby will die in minutes (high spinal, aspiration, cardiac arrest, true evidence of fetal hypoxia)
Decompressive laminectomy should be performed within how many hours of onset of epidural hematoma symptoms?
8 hours
If failed intubation occurs for an urgent c-section, what do you do?
Call for help, ventilate with 100% FiO2 with facemask or LMA, maintaining cricoid. Then assess fetal well being, if fetal distress (or maternal hemorrhage) then deliver baby while maintaining LMA with cricoid. If no fetal distress, consider waking up patient to attempt awake intubation or regional anesthesia
Neuraxial blocks cause sympathectomy how many dermatomes above sensory block level?
2-6 dermatomes
Contraindications to doing neuraxial technique
Absolute: patient refusal, bacteremia/sepsis, increased ICP, infection at needle insertion site, shock or severe hypovolemia, coagulopathy. Relative: aortic stenosis, HOCM, MVP, previous spinal surgery or spinal deformity, pre-existing neurologic disease like multiple sclerosis, severe depression of mental capacity
why do you not do a spinal after a failed epidural?
Because of risk of high or total spinal. Volume in epidural space decreases CSF space leading to more cephalad movement of local given in CSF space
Risks and benefits of epinephrine in test dose for epidural placement
Risks: false positive rate of 45% leading to unnecessary replacement of epidural, tachycardia
Benefits: help rule out intravascular injection
What to do if ACT is unchanged after heparin is given prior to going on bypass
Repeat ACT, check correct drug and dosage given, check IV line. Could be HIT. Antithrombin 3 deficiency is diagnosis of exclusion (FFP is treatment)
Advantages and disadvantages of regional anesthesia for high cardiac risk patient
First, there is no evidence that a specific anesthetic technique is associated with a better cardiac outcome. Advantages include: stress response is attenuated or blocked, vasodilation facilitates surgical anastamoses and graft perfusion for vascular surgery, decreased risk of deep vein thrombosis. Disadvantages include: potential for hypotension and bradycardia from high sympathectomy, spontaneous ventilation during lengthy surgery in a compromised patient
Patient becomes hypertensive to 200/115 in PACU, what’s your differential and what will you do? Management of severe hypertension preop and intraop?
hypoxia, hypercarbia, OSA, elevated ICP, myocardial ischemia, fluid overload, pheochromocytoma, thyrotoxicosis, drugs, withdrawal from drugs, pain, anxiety, bladder distension, malignant hyperthermia, electrolyte abnormalities. HTN crisis when BP > 180/120, HTN urgency when no evidence of end organ damage, HTN emergency when evidence of end organ damage (myocardial ischemia, CHF, CVA, arterial aneurysm, end stage renal disease). I would first confirm BP, assess ABCs, look for evidence of end organ damage, immediately treat HTN with quick acting vasodilator like nitroglycerin or nitroprusside to avoid end organ damage while monitoring mental status and cardiac ischemia.
Preop: Confirm BP, evaluate patient, assess ABCs, look for evidence of end organ damage, review history and medication compliance, counsel Patient about the risks of HTN.
Intraop: induction - exaggerated response to laryngoscopy and anesthesia, increased BP lability, relative hypovolemia because of increase in SVR. Confirm BP, assess ABCs, HR, etCO2, verify adequate oxygenation and ventilation, 100% O2, give short acting drugs, monitor for myocardial ischemia.
Patient develops hypoxemia intraoperatively, why and what would you do?
Causes of hypoxemia include: decreased delivery of oxygen (machine failure, disconnection in the circuit), hypoventilation (esophageal intubation, ETT kink or mucus plug or ruptured cuff, respiratory depression, ventilator failure), V/Q mismatch (pulmonary embolism, pneumothorax, bronchospasm, atelectasis, right main-stem intubation), intracardiac shunting, impaired diffusion (pulmonary edema, aspiration, COPD). I would make sure pulse oximeter is placed correctly, look listen and feel, assess vital signs, check pulse and etCO2 and peak airway pressures, place patient on 100% O2, hand ventilate, listen for bilateral breath sounds and see equal chest rise (if unilateral breath sounds then bronchial intubation or pneumothorax, evaluate ETT (rule out kink, mucus plug, herniated cuff, if wheezing (give albuterol, deepen anesthetic, give IV epinephrine), if I think atelectasis (give recruitment breath, hold 40 mmHg for several seconds, add PEEP to vent settings), if none of these maneuvers resolve hypoxemia, I would get ABG, consider CXR and TTE.
Patient has postop nausea, why and what will you do.
PONV could be caused by volatile anesthetics or nitrous oxide, pain, drugs (narcotics, etomidate, neostigmine), hypotension, hypovolemia, hypoxia, hypoglycemia, anxiety, myocardial ischemia, increased ICP, GI obstruction, blood in stomach, type of surgery (ENT, laparoscopic, breast). I would first go to patient’s bedside and assess vital signs, if any abnormal signs like hypoxia or hypotension, treat accordingly. If patient is hemodynamically stable, oxygenating and ventilating well, pain controlled, give anti-emetic like ondansetron. If patient still nauseous, check electrolytes, glucose level, EKG. Best way to treat PONV is prophylactic treatment, intraoperatively maintain adequate intravascular volume, give dexamethasone, limit volatile anesthetics, avoid nitrous oxide, and use propofol.
What are the factors that affect the supply and demand of oxygen to the myocardium?
Supply: coronary perfusion pressure, duration of diastole (heart rate)
, hemoglobin, oxygen saturation
Demand: heart rate, contractility (decreased contractility may be beneficial as long as coronary perfusion pressure is maintained), myocardial wall tension (increased afterload and preload increases tension which increases demand)
What to do if you see ST segment changes intraoperatively
First quickly assess cause of myocardial oxygen supply and demand imbalance, improve patient’s hemodynamics (lower or raise BP, decrease HR), give MONA therapy (morphine vasodilates to reduce preload and afterload, oxygen may limit ischemic injury, nitroglycerin dilates coronary arteries to reduce ischemic pain, aspirin inhibits thromboxane A2 platelet aggregation to reduce coronary reocclusion), obtain labs (troponin and CKMB, CBC, electrolytes, coagulation panel), inform surgeon to finish ASAP or cancel case, if patient hemodynamically unstable, consider TEE and consult cardiology. At the end of the case, if hemodynamically stable and ST changes resolved, then extubate while avoiding HTN and tachycardia and send to monitored floor with cardiology consult. If hemodynamically unstable, keep intubated, send to CCU with cardiology consult.
Which patients are at highest risk of latex allergy, and how would you manage a patient with known latex allergy?
At risk: health care workers, children with spina bifida and GU abnormalities, multiple prior surgeries, banana and avocado allergy. Preoperatively, I would notify the OR staff to remove all latex, suggest scheduling patient as first case of the day when latex particles are the lowest in the air. Intraoperatively, I would open up all rubber vials instead of sticking needle through the rubber, be prepared to treat anaphylaxis (epinephrine, vasopressin, H1 and H2 antagonists, corticosteroids, albuterol). Postoperatively, warn PACU staff regarding latex allergy, and if patient experienced anaphylaxis, require 24 hr ICU observation.
How do sickle cell anemia and sickle cell trait differ?
Sickle cell anemia is homozygous, 70-98% hbS and remainder is hbF, incidence is 0.2%. Sickle cell trait (hbAS) is heterozygous genotype via incomplete dominance, one beta-globin gene codes of hbS and the other codes for hbA, 10-40% hbS so minimal clinical symptoms, only symptomatic unless PaO2 < 20 mmHg (venous PaO2 is 30-40)
Pathophysiology of pulmonary hypertension (pHTN), signs of pHTN, treatment plan of pHTN
mean PAP > 25 mmHg secondary to hypoxia/hypercarbia or primary pHTN, sympathetic surge causes vasoconstriction, decrease SV, and increase in afterload leading to remodeling of pulmonary vasculature. Early signs are dyspnea, syncope. Exam findings include split heart sounds, pulmonic valve hregurg/tricuspid regurg, JVD, hepatomegaly, pitting edema, cor pulmonale seen on EKG. Treatment include avoiding hypoxia, hypercarbia, acidosis, hypothermia, pain. Medications include vasodilator like sildenafil, calcium channel blocker like diltiazem, diuretics, nitric oxide, milrinone, epinephrine, vasopressin.
What is modified RSI?
RSI but still checking if I’m able to mask ventilate prior to intubating. So first have difficult airway equipment in the room, 2nd pair of hands, GI prophylaxis, HOB elevated, maximize preO2, give induction agent of fentanyl/lidocaine/propofol, check ventilation with small squeeze of bag, give sux or high dose roc, then intubate.
What to do if you suspect colleague is abusing fentanyl?
Immediately go to chairman or supervisor, colleague is a danger to himself and patients, if colleague is truly abusing drugs, the best way to help is to have him sent to a drug rehab center right away
Why is cardiac output increased in obesity?
Increased oxygen consumption leads to increased cardiac output, 0.1 L for every 10 kg of extra body fat
How do you calculate FRC?
30ml/kg. So average patient of 70 kg has FRC of 2100 mL. Total lung capacity is 80ml/kg, vital capacity is 65 ml/kg, tidal volume is 7ml/kg, residual volume is 15ml/kg
How would you manage a Jehovah’s witness patient who is a minor and undergoing surgery with high risk for massive bleeding?
Preoperatively I would have a thorough discussion with parents and child about the various options, assess competence of child. In emergency case, the state is warden of the child so may legally give blood transfusion against parents’ wishes. In elective case, talk to hospital committee before proceeding, get approval from judge that child is consentable and is willing to risk death from massive hemorrhage.
What are the possible complications of using exchange catheter (bougie) to replace an ETT with a massive leak?
laceration, perforation, bronchospasm, cardiac arrest (vasovagal response to stimulating trachea, leading possibly to asystole)
what medications are being injected in an epidural steroid injection?
steroid plus local. steroid is long lasting while local works immediately
what is central pontine myelinosis and what are risk factors for developing CPM?
It is an osmotic demyelination syndrome associated with irreversible neurologic deficits (dysarthria, dysphagia, quadriplegia, coma) which develop 2-6 days after treatment for hyponatremia. Risks include Na < 120 (it would be lead to seizures), rapid correction, development of hypernatremia with rapid correction.
How does dehydration cause fever?
Patient is so dehydrated he cannot sweat, so heat cannot be exchanged with the environment as well. Also hypoperfusion of hypothalamus can lead to temperature dysregulation
Why is caffeine used in caffeine-halothane contracture testing for diagnosis of malignant hyperthermia?
caffeine is used as control because it causes contraction in fresh muscle biopsy.
Causes of fever preoperatively
infection, dehydration, micro aspiration, atelectasis. Fever increases MAC
what are the anatomical landmarks for doing a transgluteal sciatic nerve block?
greater trochanter and posterior superior iliac spine, midpoint between the two, then 4 cm distal to midpoint
If patient has NG tube in situ for small bowel obstruction, would you use nitrous oxide for maintenance?
No, first because nitrous oxide does not provide a full MAC of anesthesia, second a NG tube may be up against stomach lining and not reliably providing suction so bowel distension can still occur.
What is BIS monitor and what are the benefits and problems?
BIS is bispectral index monitoring, a proprietary processed EEG monitor to evaluate depth of anesthesia. Benefits: Can allow use of lower amounts of anesthesia, help reduce intraop recall, slightly quicker emergence. Problems: not reliable, opioids do not affect signal, not helpful when using nitrous oxide or ketamine, cannot use in children < age 5, does not predict movement in response to surgical stimulation.
What are kerley B lines?
Short parallel lines seen at lung periphery on a CXR, caused by fluid or cellular infiltration into interstitium, can be a result of pulmonary edema, fibrosis, pneumonia, and lymphoma. Associated with congestive heart failure.
Would you use a combined spinal-epidural technique?
Can cause a more sudden sympathectomy leading to severe hypotension, so I would prefer to do a plain epidural because I can titrate local slowly to raise level of surgical block
If you get a wet tap from an epidural, do you go above or below?
Go above because if you go below, there may be spinal fluid leaking out that distorts anatomy
Dyspnea after epidural placement in laboring patient, what’s going on?
High spinal, pulmonary edema worsening (if patient has PIH/pre-eclampsia), bronchospasm, PE, eclampsia, vena caval compression (place patient in LUD)
If laboring patient develops high spinal after placement of neuraxial block, what would you do?
Give 100% oxygen, ensure adequate oxygenation and ventilation, open up fluids, give epinephrine to improve circulation, sit patient up
If laboring patient develops severe hypotension from high spinal, what would you do?
Call for help, secure airway, left uterine displacement, more fluids, vasopressors, arterial line
If laboring patient develops high spinal with severe hypotension, will you deliver if there is fetal distress?
No, because starting c-section may worsen hypotension from loss of blood, so I would stabilize mother’s hemodynamics knowing cause of fetal distress is because of severe maternal hypotension
Would you give atropine or glycopyrrolate to treat fetal bradycardia in a mother with severe hypotension causing fetal distress?
No, because atropine does not cross placenta, and in this case, the cause of fetal bradycardia is decrease in uteroplacental perfusion, so I would improve the mother’s hemodynamics, place mother in LUD to treat fetal bradycardia
If newborn has APGAR score of 4, what do you do?
First make sure mother is stable before assisting with newborn. Then, have someone assess term gestation, breathing, and muscle tone. Provide warmth, clear airway, dry, stimulate, reposition head for sniffing position. If apneic or HR<100, provide positive pressure ventilation. If HR<60, add chest compressions with 3:1 ratio of compressions to breaths, 90:30 in a minute. If HR<60, consider intubation (prolonged bag mask ventilation, poor bag mask ventilation), epi 10mcg/kg, and volume.
Seizure in PACU, how do you manage?
Go to bedside, assess if seizure if real, then call for help, suction airway, turn the head, give midazolam (because there is a reversal agent), support airway, prepare to intubate
what are indications to give antibiotics for aspiration pneumonitis?
fecal contaminant, diagnosis of pneumonia
If surgeon complains of patient’s tachypnea during bronchoscopy to remove foreign body, what do you do?
Give small doses of fentanyl to slow down respiratory rate but maintain spontaneous ventilation
What is creatinine?
metabolic product of muscle breakdown that is excreted renally, so it can be used to measure renal function
What is BUN (blood urea nitrogen)?
by product of liver metabolism, it’s used in a ratio of BUN to Cr to help determine cause of renal insufficiency
What are side effects of EPO while on dialysis?
Hyperviscosity, hypertension, tachycardia, headache, dyspnea, diarrhea, increased risk of CVA/MI
If you had to have a number, what number would you transfuse blood?
Hemoglobin (hgb) < 6, because then mortality and morbidity begins to rise
why not place arterial line in AV fistula?
risk of infection and thrombosis
What is mass spectrometry used for in anesthesia machine?
Analysis of molecular mass to the charge can determine concentration of gases, including volatile agents.
Gradual hypoxemia intraoperatively over 10 minutes, what’s the differential?
inadequate oxygen delivery, hypoventilation, atelectasis, aspiration
what are your concerns when surgeon requests to increase bovie setting?
Poor surgical hemostasis, coagulopathy, short circuit (patient sweating to poor bovie pad contact with skin, which can lead to bovie pad burn)
What component of PFTs (pulmonary function tests) is best to evaluate COPD?
Spirometry, FEV1/FEV, look at severity of disease and responsiveness to bronchodilator treatment (12-15% increase in FEV1)
How does neck radiation affect the airway?
scarring, airway tissue friability, emergency airway may be challenging
What are the advantages and disadvantages of smoking cessation 2 days prior to surgery?
Advantage: decreases level of carbon monoxide to improve oxygenation. Disadvantage: increases sputum production and more reactive airways leading to decreased pulmonary function. Best to stop 6-8 weeks prior to decrease overall postop M&M
In non-smoking patient, what’s the carboxyhemoglobin level?
1-3% from heme metabolism and environment
Signs of hypothyroidism?
fatigue, muscle weakness, hypotension, slow mentation
Area under arterial line waveform can give you what information?
stroke volume, and therefore MAP assuming you know HR and SVR. upstroke tells you about contractility. downstroke may tell you about valvular disease.
How would you anesthesize airway for awake fiberoptic for a patient who has had neck radiation?
No nerve blocks because of anatomy distortion and friable tissue, I would use atomizer to spray aerosolized lidocaine then spray lidocaine from tip of scope as it is passed into airway
How does bronchospasm cause hypotension?
Bronchospasm decreases cardiac output through pulmonary vasculature leading to hypotension
What’s the difference between biphasic and monophasic defibrillators?
Biphasic is newer, energy goes through myocardium twice so you can use lower joules
what’s the mechanism of tourniquet pain?
unmyelinated C fibers are very hard to block
how to minimize tourniquet pain?
minimize tourniquet time, give ketamine because there are NMDA receptors associated with the unmyelinated C fibers
Patient slowly desaturates in PACU, why and how would you evaluate?
hypoventilation, atelectasis, aspiration, MI, CHF. I would go to the bedside, assess patient’s vital signs, breathing, listen to breath sounds, check ETT if in place, if needed, get an ABG and CXR
How do you treat patient with cardiogenic pulmonary edema?
Raise HOB, give a diuretic, rate control
What causes increased gradient between etCO2 and PaCO2?
Increased V/Q ratio (aka increased dead space), including pulmonary embolism, low cardiac output, PEEP, positive pressure ventilation (dead space increases from 33% in awake to 50% in ventilated)
How do you manage postop delirium?
Go to beside, do a focused history and physical, first evaluate for causes like hypoxia and hypercarbia, ICU delirium, medications given, electrolyte abnormalities, and then address any deficiencies.
How do you differentiate delirium from stroke?
With delirium, symptoms fluctuates during the course of the day
Why is there desaturation after insufflation of peritoneum? How would you evaluate?
Bronchospasm, bronchial intubation, restrictive lung pattern from insufflation. I would assess vital signs, turn O2 to 100% while hand ventilating to feel for compliance and look for bilateral chest rise and listen to bilateral breath sounds, check ETT placement
Why would a child with upper airway obstruction desaturate while receiving supplemental oxygen?
Dry oxygen leading to worsening closure of airways, so give humidified oxygen instead
what does upstroke of arterial line waveform tell you?
contractility
Advantages and disadvantages of using desflurane
Quick onset, quick removal so faster emergence. However it’s expensive, can cause tachycardia and dysrhythmias, pungency is strong and irritating to airways to not good for inhalational induction
How does isoflurane provide myocardial protection or preconditioning?
Isoflurane lessens tissue injury for up to 2-3 days if myocardial tissue is exposed to an ischemic event
What are contraindications to using CPAP?
pneumothorax, epistaxis, recent ENT surgery, basilar skull fracture
How does HTN and hypoxia cause PVCs?
Over time HTN causes myocardial tissue remodeling, stretching the tissue. Hypoxia to the myocardial tissue leads to PVCs
What drugs exacerbate WPW (Wolff Parkinson White) syndrome?
beta blockers, calcium channel blockers, and adenosine because they affect the AV nodal pathway. Can use amiodarone, procainamide, and cardioversion to treat WPW
Celiac plexus block complications and what injectate do you use?
Complications include orthostatic hypotension, diarrhea, back pain, infection, bleeding. I would inject a combination of alcohol and local
How does alcohol work to cause pain relief in a nerve block?
Alcohol causes neurolysis (nerve destruction) by extracting phospholipids, cholesterol and cerebroside from neural tissues and precipitating mucoprotein and lipoprotein.
Definition of difficult intubation?
Intubation needs more than 3 attempts or more than 10 minutes. History of difficult intubation is the #1 predictor of difficult airway
What would you see on CXR that indicates a patient has pHTN?
large pulmonary vasculature
Which H2 blocker is better to use?
famotidine because it has less cardiac side effects
How to manage OR fire?
Call for help, remove what’s on fire, stop flow of all airway gases, extinguish burning materials by pouring saline
How to manage airway fire?
Call for help, stop flow of all airway gases, remove ETT, pour saline into airway, if fire not extinguished then use CO2 fire extinguisher. Re-establish ventilation, wait 1-3 minutes before administering oxygen because it can re-ignite fire
Pediatric patient with heart murmur, are you concerned? need further workup?
Depends if it’s benign (functional) or malignant (structural). If patient is blue, failure to thrive, then need further work up. Up to 90% of kids have a functional heart murmur.
What are signs and symptoms of acetaminophen toxicity?
It occurs in 3 phases. First phase (first 24 hours), you can have nausea, sweating, but oftentimes no or mild symptoms. 2nd phase (24-72 hrs), see signs of liver damage such as RUQ pain, elevated liver enzymes, acute kidney failure. 3rd phase (3-5 days), fulminant liver failure with coagulopathy, death.
What’s the pathophysiology of acetaminophen toxicity?
Acetaminophen overdose saturates the sulfate and glucuronide metabolic pathways so there is overproduction of NAPQI which is a toxic metabolite that causes acute liver necrosis.
How does N-acetylcysteine work to treat acetaminophen overdose?
It replenishes supply of glutathione, which detoxifies NAPQI.
What is normal ICP (intracranial pressure)?
7-15 mmHg
Intubated patient is thrashing and pulling out lines in the PACU, do you extubate?
No, rule out hypoxia, hypercarbia, acidosis, and hypotension to determine cause of thrashing, then treat appropriately
What are special extubation concerns with a Ehler-Danlos patient?
Be very careful to avoid bleeding because of friable tissue
What is normal cardiac output, cardiac index, SVR, CVP, PAP, and wedge pressure?
CO (4-8 L/min), CI (2.4-4 L/min/m^2), SVR (800-1200 dynes*sec/cm^5), CVP (2-6 mmHg), PAP (25/10 mmHg), Wedge (5-12 mmHg)
What’s the problem with using a succinylcholine infusion for a short case?
Risk of phase 2 block which can’t be reversed
In preop, patient is wheezing, but doesn’t respond to albuterol, epinephrine, and prednisone, what do you do?
Get ABG and cancel case, reschedule in 4-6 weeks.
Definition of OSA (obstructive sleep apnea)?
Complete apnea for 10 seconds, five times per hour, associated with a 4% decrease in SaO2
Clinical signs of pHTN
dyspnea, fatigue, blueish lips, JVD, hoarseness (pulmonary vasculature can be up against recurrent laryngeal nerve)
EKG signs of pHTN
right axis deviation, RBBB, peaked T waves, right atrial enlargement
Sequelae of pHTN
RVH, cor pulmonale, tricuspid regurgitation
How do you determine if a chronic pain patient is drug seeking or actually in pain?
Start remifentanil gtt until patient is comfortable, then turn off and calculate how much narcotic use
Patient with electrical burn, what tissues are most affected?
Nerves, blood, muscle, skin, tendon, fat, bone
What kind of abnormal EKG can intracranial bleed lead to?
inverted T waves
what questions to ask surgeon prior to intracranial bleed surgery?
hemodynamic goals intraop and postop, how long the procedure will take, will a wake up test at end of case be done?
what causes lethargy in a patient with head injury?
brain edema, increased ICP, vasospasm
what are diagnostic tests for increased ICP?
head CT, lower BP and assess mental changes, drain CSF and assess mental changes
How does HAART therapy for HIV affect induction of anesthesia?
HAART therapy can increase risk of CAD
How much CSF can be drained at one time for elevated ICP?
10-15 mL of CSF, can’t drain too much because ventricles can collapse bridging veins leading to rupture and more bleeding
PALS compression:ventilation ratio, shock energy, and epinephrine and amiodarone and adenosine doses
15:2, 2J/kg, epinephrine 10 mcg/kg IV or 100 mcg/kg via ETT, amiodarone 5 mg/kg, adenosine 0.1 mg/kg
what are anesthetic considerations for hepatic tumor resection?
preop: possible full stomach 2/2 ascities, prepare for blood loss and large lines intraop: keep low CVP during resection to avoid engorging liver to make it easier to resect, also minimize surgical time, restrictive ventilation. postop: bleeding issues, postop ventilation
sunken eyeballs, sunken fontanelles, decreased skin turgor mean how much is pediatric patient dehydrated?
sunken eyeballs = 15%, sunken fontanelles = 10%, decreased skin turgor = 5%. Start volume resuscitation at 10 ml/kg until endpoint that labs are normal
why is a cooked peanut less damaging than uncooked peanut if it is aspirated into lungs?
because cooked peanut has fatty acids removed. fatty acids cause more damage to the lungs
How would you evaluate postop jaundice?
Perform focused history and physical, review perioperative record looking for underlying liver dysfunction or prehepatic (hemolysis from transfusion or hematoma), hepatic (direct hepatocellular injury like viral or hypoperfusion or drugs), and posthepatic (obstructive from stone or stricture or injury) causes.
Risk factors for developing HIT (heparin induced thrombocytopenia)
> 5 days of heparin use, surgical patients, female
what is treatment for dystonia caused by metoclopramide use?
diphenhydramine
mechanism of ticlodipine, benefits and downsides to its use
ADP inhibitor causing irreversible platelet dysfunction, benefits: cheap, works well downsides: need to wait 14 days prior to neuraxial technique, causes neutropenia
what is normal cerebral blood flow? at what flow does cerebral ischemia occur? how about brain tissue death?
50 ml/100g/min, 18-20 ml/100g/min, 8-10 ml/100g/min
What are signs of poor prognosis for someone with an intracranial hematoma?
on CT scan > 3 cm (surgery required), no corneal reflexes, low GCS, SBP > 200 mmHg
Causes of postoperative fever
POD1 (wind) : atelectasis, aspiration. POD3 (water): UTI, POD5 (wound) surgical infection, line infection, pneumonia. POD7 drugs like antibiotics
if epidural is working well with no side effects, what is the one downside for vaginal delivery?
epidural can increase risk of forcep delivery
Causes of hypotension with insufflation of abdominal cavity, and how would you manage?
hypovolemia, compressed vena cava, CO2 embolism, stretching of peritoneum causing vasovagal response. optimize intravascular volume, decrease insufflation pressure (15 is normal)
Causes of why a new ETT cannot be passed over a Cook airway exchange catheter?
ETT too big, airway edema, getting caught up on arytenoids or vocal cords (turn ETT 90 degrees after meeting resistance or use video laryngoscope to help visualize)
what’s the cause of low ejection fraction in a patient with pure mitral stenosis?
fibrosis of left ventricle area near the mitral valve is immobilized leading the decreased LV function
mechanism of digoxin?
inhibits sodium potassium ATPase leading to increase in intracellular sodium and calcium which decreases heart rate (increased calcium lengthens phase 4 and 0 of cardiac action potential) and increases contractility. Thus used for atrial fibrillation and CHF
how to manage suspected compartment syndrome?
Go to patient’s bedside, assess for compartment syndrome (Five P’s - pulselessness, pallor, paralysis, paresthesia, and pain), ensure adequate oxygenation, ventilation, and circulation, place pulse oximeter on distal extremity, this is a surgical emergency, treatment is a fasciotomy. Regional anesthesia is controversial but data does not support withholding a nerve block
How to manage hypotension and bradycardia following induction for a cardiopulmonary bypass (CPB) case?
100% FiO2, open up fluids, check for pulse, look at monitors especially EKG and etCO2 and airway pressures, give ephedrine to temporarily improve BP, ensure ETT is correct depth, feel for compliance, bilateral breath sounds, turn down inhaled anesthetic, if fluids and pressors do not work or you now see ST elevations then quickly prep for crash bypass.
How does DDAVP help with bleeding after cardiopulmonary bypass (CPB) case?
Likely cause of bleeding is from platelet dysfunction from being on bypass, and DDAVP induces release of vWF (von Willebrand factor) and factor VIII from endothelial cells that leads to improvement of platelet adhesion and aggregation.
Causes of bleeding following cardiopulmonary bypass (CPB) case?
hypothermia, inadequate reversal of heparin, hemodilution of coagulation factors, platelet dysfunction, DIC, inadequate replacement of coagulation factors, inadequate surgical hemostasis
Causes of Torsades de pointe, and treatment
Causes: prolonged QT interval, hypokalemia, hypomagnesia, hypocalcemia, hypothyroidism, hypothermia, droperidol, other meds that cause prolonged QT. Treatment: Magnesium, unsynchronized cardioversion if unstable, therapy to shorten QT interval such as lidocaine or increasing heart rate like isoproterenol or pacing.
Are etNitrogen and TEE specific or sensitive to venous air embolism?
etNitrogen is specific because nitrogen has to be air. TEE is sensitive but not all bubbles seen on TEE is air.
Complications from blood transfusion
allergic reaction, transfusion reaction including fever or hemolysis, infection including hepatitis C/HIV, TRALI, citrate toxicity (treat with calicium), hyperkalemia
What is ecstasy?
MDMA, a psychoactive drug that can cause hyperthermia and dehydration, metabolized by liver, renally excreted
when should elective surgery be performed in a patient who has recently suffered a concussion?
No guidelines, but probably best to wait for post-concussive symptoms to resolve, and if there are any symptoms, delay case to obtain a neurology consult to evaluate prior to proceeding. For major traumatic brain injury, there’s a risk of further neurological damage.
What is in EMLA cream and how long does it take to work?
Lidocaine and prilocaine, with prilocaine there is risk of methemoglobinemia. It takes at least 20 minutes for EMLA to start working.
Do you need to get a TTE for all patients undergoing a sitting crani?
No, unless evaluation results in possible valvular disease or interseptal defect
When does a PFO seal completely?
Within a few months after birth, 75% of PFOs close up.
What are symptoms of PFO?
Most people don’t have symptoms, however patient can have migraines and increased risk of TIA and strokes
Does atropine extinguish oculo-cardiac reflex?
No
Child with sickle cell disease complaining of abdominal pain, what’s the cause?
splenic sequestration causing splenomegaly, pallor, and lethargy. It can lead to hypovolemic shock and requires PRBC transfusion or splenectomy.
How does transcranial doppler detect cerebral vasospasm?
increase in arterial velocity (> 200 cm/s is high risk for infarct). Gold standard is cerebral angiography
what’s the endpoint for HHH therapy? (Hypertension, Hypervolemia, Hemodilution)
Cardiac output is maximized
Techniques to assist surgeon to dissect around a cerebral aneurysm
Temporary clip, adenosine (30-45 seconds of circulatory arrest, 6-12 mg, have crash cart and defib pads on patient)
During a cerebral aneurysm case, would you want hypotension or hypertension?
I would want tight hemodynamic control, however, hypotension is preferable because hypertension can increase risk of aneurysm rupture or worsen an aneurysm that has already ruptured
Describe ICP compliance curve
There is autoregulation of ICP with varying intracranial volume, however as mass effect increases, autoregulation goes away, and at the elbow of the curve is when ICP is about 15 mmHg
If a patient is starting to have breakthrough pain with a lumber epidural, how would you manage?
I would go to patient bedside, do a focused history and physical. I would first want to make sure the epidural catheter is functioning, so I would exam the patient’s back, give a test bolus of lidocaine, and if epidural is not functioning then replace epidural, if epidural is functioning then adjust concentration and rate of local anesthetic infusion and consider adding opioid for synergistic effect. Avoid morphine in epidural in patients at extreme of age because of late/delayed respiratory depression.
What type of sympathetic block is used to treat lower extremity CRPS?
lumbar sympathetic block
How would you manage ECT case for a pediatric patient with high risk of difficult airway?
First time ECT, secure the airway with a fiberoptic scope in a controlled fashion with inhalational induction or ketamine to keep patient spontaneously breathing, then perform direct laryngoscopy to see difficulty of intubation. If patient is deemed to be easy to intubate then subsequent ECT sessions can be done with an unsecured airway.
Why does pediatric patient go into asystole during ECT case?
ECT causes both sympathetic and parasympathetic stimulation, and in a pediatric patient there may be exaggerated vagal tone that leads to asystole
which anesthetic drugs increase seizure threshold (aka shorten ECT seizure duration)?
benzodiazepines, propofol, lidocaine, beta blockers. Drugs that decrease seizure threshold (etomidate, caffeine, lidocaine). Drugs that don’t affect threshold (ketamine, methohexital, opioids). Sevoflurane is associated with seizures.
How to avoid hoarseness caused by vocal cord injury from ETT?
Minimize intubation time, use smaller tube, use decreased ETT cuff pressure, use humidified gases.
What is felty syndrome?
Triad of rheumatoid arthritis, splenomegaly, and neutropenia
Anesthetic concerns with congenital diaphragmatic hernia?
pHTN causing massive shunt, so avoid hypoxia, hypercarbia, acidosis. Possible pneumothorax of good lung, so low tidal volumes, avoid PEEP and nitrous oxide. Avoid further insufflation of stomach to avoid risk of aspiration, so keep NG tube to suction, gentle mask ventilation. Reversal of left to right shunt which will cause hypoxemia, so maintain preload (avoid PEEP) and SVR (avoid drugs that drop SVR like propofol). Post-repair may have difficulties closing abdomen which may cause hypoventilation and high peak pressures, so keep patient intubated (which also helps to treat pHTN, can use just fentanyl for sedation because it maintains good hemodynamics) and use low tidal volumes.
what’s the mechanism of nitric oxide?
Direct vasodilator by activating guanylyl cyclase which increases cGMP which decreases intracellular calcium leading to smooth muscle relaxation of the pulmonary vasculature only because of a half life of only a few seconds
what is high frequency ventilation?
Very high respiratory rate of 60-120/min with small tidal volumes to minimize airway peak pressures while maintaining oxygenation with permissive hypercapnia.
Reason to intubate a pediatric patient with history of seizures for MRI?
Risk of aspiration, high frequency of seizure activity, need to better control oxygenation and ventilation for increased ICP
Special considerations for a first trimester pregnant woman going for emergency surgery
Avoid medications that can possibly be teratogenic (nitrous oxide - neural tube defect, benzodiazepines - cleft palate), induction of spontaneous abortion with general anesthesia so try regional technique if possible, decreased MAC, decreased neuraxial local anesthetic dose
Indications for ICP monitoring
GCS 8 or less and abnormal CT scan, or GCS 8 or less with normal CT and any two of following: age > 40, motor posturing, SBP < 90
What’s the concern of using PEEP in a patient with increased ICP?
PEEP decreases venous return, thus may increase ICP, however PEEP can improve oxygenation, thus may decrease ICP
Complications from mannitol administration
Increase in plasma osmolality can increase intravascular volume leading to CHF, then cause hypotension from hypovolemia, as well as electrolyte abnormalities and renal insufficiency from the hyperosmolar state
Indications for corticosteroids in patients with increased ICP
Increased ICP is caused by localized cerebral edema around a brain tumor, particularly metastatic tumors and glioblastomas. Steroids do not improve outcome or lower ICP in severe traumatic brain injury (TBI)!
Techniques to treat a taut dura
propofol, benzodiazepine, mannitol, furosemide, improved position of head, increased neuromuscular blockade, hyperventilation
what’s decorticate and decerebrate posturing?
Decorticate posturing is flexion of arms, damage to cerebrum, 3 on motor part of GCS. Decerebrate posturing is extension of arms, damage to brainstem, 2 on motor part of GCS.
Postoperative issues following a traumatic brain injury (TBI)?
Sympathetic hyperactivity leading to left ventricular dysfunction, trauma-associated acute lung injury, seizures (prophylactic anti-epileptics given), depressed immune system leading to pneumonia, brain thromboplastin is released leading to disseminated intravascular coagulation (DIC),
Causes of cerebral salt wasting syndrome
head injury, intracranial tumor or surgery or bleed, cerebral ischemia, meningitis
Causes of diabetes insipidus
central (trauma, neoplasm, infection, vascular). nephrogenic (infection, vascular, metabolic, drugs like lithium and demeclocycline)
what’s the incidence of intraoperative recall and awareness?
< 1% for explicit recall, so awareness is higher
risk factors for intraoperative recall
cardiac, emergency, trauma, equipment failures, increased MAC.
stages of hypovolemic shock
4 "tennis" stages: stage 1 (up to 15% blood loss) stage 2 (15-30% blood loss) stage 3 (30-40% blood loss) stage 4 (over 40% blood loss) Usually signs and symptoms of shock appear at stage 2, such as delayed capillary refill, tachycardia, pale and clammy skin, decreased urine output.
What structures are within the cavernous sinuses that surround the pituitary gland?
internal carotid arteries, and cranial nerves 3/4/6.
Anesthetic considerations for acromegaly patient
Difficult airway with large tongue and enlarged epiglottis and subglottic stenosis, HTN, OSA, peripheral neuropathies, hypergylcemia
Anesthetic management for a patient with tetralogy of Fallot (TOF)
Maintain intravascular volume and SVR (avoid histamine releasing drugs), avoid increases in PVR (avoid hypoxia, hypercarbia, acidosis, increased airway pressures), treat cyanotic spells with volume, phenylephrine, and propranolol (which can help relieve infundibular spasm)
what are the unique features of the fastrach LMA?
It is an intubating LMA with a rigid handle to facilitate one handed use, an epiglottis elevating bar, and wide enough opening for a 8.0 cuffed ETT
if you have difficult time placing epidural for an urgent c-section and have a wet tap, why would you want to use a spinal catheter instead of inject a one time dose through tuohy needle?
In case duration of surgery is prolonged, and do not inject through tuohy because it is much larger than a spinal needle so there is risk of high spinal, and give 1/4 of spinal dose at a time to slowly titrate
Treatment for croup
Typically can treat with staying calm and upright, fluids, and cool humidified air. If persistent for several days or more severe can give decadron and racemic epi and hospitalization.
if blood is coming out of ETT, what do you do?
Call for help, a double lumen ETT, and vascular surgeon. You want to isolate the bleeding to one lung so you can ventilate and oxygenate the patient.
Patient has DNR/DNI order but is not competent to consent for surgery, what do you do?
If it is elective, then wait for power of attorney. If it is emergent, then 2 physician consent.
What’s dosing of dopamine for renal, heart rate, and blood pressure?
1-5 mcg/kg/min (dopaminergic), 5-15 mcg/kg/min (beta), 20-50 mcg/kg/min (alpha, may cause tachyarrhythmias)
Patient agitated in PACU, why and what will you do?
hypoxia, hypercarbia, electrolyte abnormality, hypoglycemia, CVA, increased ICP, acid-base abnormality, pain, bladder distension, drugs, residual anesthetics. Go to bedside, assess mental status, vital signs, give supplemental oxygen, assess first for hypoxia and hypercarbia, then assess other possibilities.
How do you monitor MEP (monitor evoked potential) and give neuromuscular blockade?
Can still do MEP as long as there are 2 twitches with twitch monitor. I would use an infusion of neuromuscular blockade and use twitch monitor throughout case.
How do you differentiate neuropathic pain from nociceptive pain?
Neuropathic pain results from damage or dysfunction of peripheral or central nervous system causing burning, tingling, numbness. It doesn’t respond to opioids so tx = anti-depressants, anti-convulsants, and physical therapy.
Nociceptive pain is damage to body tissue causing localized, throbbing, aching pain that responds well to opioids.
what’s the pathophysiology and treatment of hereditary angioedema?
C1 esterase inhibitor deficiency leads to overproduction of bradykinin, which is a potent vasodilator and increases vascular permeability. It doesn’t respond to antihistamines, corticosteroids, or epinephrine so acute treatment is FFP which contains C1 esterase inhibitor. lupusProphylaxis with androgens because they can inactivate kinins. Triggers for hereditary angioedema include infection, dental work, surgery, stress, minor injuries.
Differential diagnosis for blood in foley catheter
Traumatic foley insertion, UTI, bladder cancer, kidney stone, hemolysis
Differentiate between febrile, hemolysis, and anaphylaxis reactions with blood transfusion.
febrile (recipient antibodies against donor antigens, mild and self-limiting fever, tx = acetaminophen). hemolysis (ABO incompatibility, hemoglobinuria, hypotension, DIC, renal failure, tx = 100% O2, stop transfusion, give fluids and pressors, support renal function with diuretics and maintain blood pressure). anaphylaxis (IgA deficiency patients have immediate reaction, tx = stop transfusion, anaphylaxis therapy)
mechanism of action for hydralazine
vasodilator that is a direct acting smooth muscle relaxant of arterioles. high risk of causing lupus (SLE)
mechanism of action for magnesium
vasodilator
ASA recommends herbal medications that may increase bleeding to be held for how long prior to surgery?
2-3 weeks
Why does it matter if a Jehovah’s witness patient has acute or chronic anemia prior to major surgery?
If it is acute, then likely active bleeding and case is emergent so take steps to minimize risk of death like staging surgery. If it is chronic, then consider delaying case to treat anemia with iron and EPO if possible.
mechanism of postop apnea in infants less than 60 weeks post-conception?
immature respiratory center, IV caffeine infusion has been proven to reduce risk, monitor patient at least 12-24 hours postoperatively.
If PFTs are borderline risk for a pneumonectomy being incompatible to life, how do you proceed?
Put patient under general anesthesia and do a split lung function test by placing PA catheter to block PA and have surgeon clamp bronchus. If ABG and PA pressures are not tolerable, then just do a lobectomy. If patient can tolerate, then proceed with pneumonectomy.
Mediastinoscopy for large anterior mass causing tracheal compression, how do you prepare?
Have major lines pre-induction, have ENT surgeon for rigid bronchoscopy, thoracic surgeon to open chest, and vascular surgeon for fem-fem cardiopulmonary bypass, lower extremity IV access. Even with a little sedation during or after awake fiberoptic intubation, trachea can be compressed.
What are guidelines for how gastric tube feedings should be managed prior to surgery?
If feedings are given via bolus, then wait 2 hours after last feeding to proceed. If feedings are given continuously, then feedings can continue up until surgery starts (can suction g-tube to check for volume of residual gastric contents, especially if prone case or other type of higher risk aspiration case).
What are your options if you cannot obtain an IV in an obese pediatric patient who is to undergo an emergency surgery?
Ask colleagues for assistance, try EMLA cream, use ultrasound machine, hold down patient if not cooperating, look at lower extremity if possible. If unsuccessful, since it is an emergency surgery, you don’t want to waste too much time obtaining IV access, so I would have difficult airway cart and help in the OR, minimize risk of aspiration with head of bed up and cricoid, and give IM ketamine or do an inhalational mask induction.
testicular torsion is urgent or emergent?
surgical emergency
How can you tell if ascites is caused by ovarian cancer or liver disease?
ovarian cancer causes inflammation so ascitic fluid’s protein content is high
If a stress test is positive, how do you interpret the stress test to determine if patient needs further cardiac workup?
Look at how high the heart rate goes before test shows signs of ischemia. Assuming patient can tolerate high heart rate, then I will proceed without further testing.
What causes overdamped or underdamped arterial waveform?
Overdamped (one or no oscillations after flushing arterial line; SBP falsely low and DBP falsely high): clot in catheter or air bubble in the tubing, loose connections, kinks, stiff tubing
Underdamped (several oscillations after flushing arterial line; SBP falsely high and DBP falsely low): long, very compliant catheter or tubing, tachycardia, high cardiac output
Remember that MAP is not affected by either overdamping or underdamping
What’s the most effective way to warm a patient with hypothermia ?
Bair hugger via convection. Although radiation is the number one cause of heat loss, using radiant heat like warming the room or using heat lamps is not as effective as convection because you will still have convective heat loss.
Why not inject anti-spasm medication into arterial line prior to removing it when vasospasms may be causing ischemic hand?
Injecting anything may dislodge a clot and worsen the ischemic limb
Why is FENA better than Bun/Cr to evaluate oliguria?
BUN is affected by other factors such as transfusion, bleeding, liver disease.
Why do you avoid hyperventilation during ACLS?
Hyperventilation can lead to increase in thoracic pressure which can decrease cardiac output
If FFP, platelets, cryo, factor 7 have been given but patient is still bleeding, what else can be given?
Prothrombin complex concentrate which contains factors 2,9, 10 (3 factor PCC) and sometimes also factor 7 (4 factor PCC). It reverses coagulopathy caused by warfarin, liver disease, and hemophilia. It’s contraindicated in patients with DIC (further fuels DIC) and HIT (because it contains heparin).
When can a minor legally consent for themselves?
Emancipated when they are married, parents, military, economically independent, pregnant
Do you tell patient if you forgot to give antibiotics prior to incision?
Yes, it is less than standard of care, so you take responsibility because if there is a subsequent procedure for a surgical infection, the patient needs to know.
Why does patient with mitral stenosis develop chest pain after getting an epidural for a c-section?
Hypotension from sympathectomy caused by decrease in SVR and the reflexive tachycardia both lead to decrease in coronary artery perfusion.
What’s the depth of chest compressions for an infant/child?
1/3 to 1/2 of AP diameter
When to discontinue resuscitative efforts for a newborn?
10 minutes if there no signs of life (no heart beat, no respiratory effort). How about adults? A general approach is to stop CPR after 20 minutes if there is no ROSC or viable cardiac rhythm re-established, and no reversible factors present that would potentially alter outcome.
What level of sensory block do you need to provide adequate analgesia after c-section?
T6
Patient with mitral valve disease complains of dyspnea following blood transfusion and massive fluid resuscitation, what’s the differential?
Pulmonary edema 2/2 mitral valve disease, TRALI, CHF, MI, PE. Check vital signs, EKG, CXR, give O2, raise head of bed, give lasix, consider milrinone (PDE3 inhibitor) to help reduce preload and afterload.
What are side effects of milrinone?
arrhythmias, thrombocytopenia, hypotension
What are contraindications for doing a CEA?
100% occlusion, severe sequelae from CVA, patient not optimized. #1 complication from CEA is? MI
Alternative to heparin for CABG?
argatroban, a direct thrombin inhibitor, no reversal agent.
How do you diagnose pulmonary contusion?
Difficult to diagnose, but can see chest bruises, rib fractures, hypoxemia. CXR won’t help early diagnosis, so can only see extent of injury after 24-48 hrs. Pulmonary contusion can lead to ARDS and pneumonia.
Advantages and disadvantages of mapleson circuits
Pros: cheap, portable, low resistance, no valves, less dead space.
Cons: No scavenging, loss of heat and humidity, high fresh gas flows needed
How do you provide cricoid pressure if you suspect unstable cervical spine?
Manual posterior cervical spine support can reduce motion
Do you need a central line for a sitting craniotomy?
No, but if there are no contraindications or difficulties placing one, then I would because it is the only way to remove air in case there is a venous air embolism. If you don’t have central line, need to minimize risk of air entrapment including having surgeon flood field with saline and add bone wax to seal edges of the skull after removal.
why is succinylcholine contraindicated in myasthenia gravis patients?
High risk of phase 2 blockade, ,especially if they are on pyridostigmine.
Signs when blood loss is 30-40% of blood volume
HR 120, hypotension, positive cap refill test, RR 30-40, confused, urine output 5-10 mL/hr
Differential for respiratory distress, hypotension, pulmonary edema, and fever during or immediately after transfusion
Circulatory overload/MI (JVD, high CVP, high wedge)
Anaphylaxis (rash, edema, stridor, bronchospasm)
Hemolysis/infection (sepsis, DIC, oliguria)
TRALI (looks like ARDS, supportive care, self-limiting)
Class 1 recommendation is to wait how long after a coronary balloon angioplasty to undero non-cardiac surgery?
Wait 14 days
Starting dose of albumin? side effects of albumin?
0.5 g/kg or 10 mL/kg albumin 5% or 2 mL/kg albumin 25%. allergic reaction, N/V, flushing, F/C
Intraoperative hypercarbia, what do you do?
100% O2, check vital signs including temp, check vent settings/CO2 absorber/machine valves, check ETT, check what the surgeon is doing.
Dose of methylene blue for treatment of methemoglobinemia
1-2 mg/kg over 5 min, max dose 7-8 mg/kg. alternative treatments for methemoglobinemia (use co-oximetry) include: blood transfusion, exchange transfusion, hyperbaric O2, ascorbic acid in G6PD deficiency patients
Medications approved for intra-arterial administration
benzodiazepines, opioids, succinylcholine, atropine, vecuronium
Why do a regional technique while a patient is awake ?
Help avoid paresthesias, recognize intravascular injection
How does a burn patient react to nondepolarizing muscle relaxant?
Resistance, likely due to extrajunctional receptors, dose of nondepolarizer can be 3-5 times normal, > 60 days after burn event
What degree of burn is it if a burn patient doesn’t have much pain?
Pain is not an indicator of the severity of the burn, however, in third degree burns, the nerve endings are destroyed and therefore these burns usually are not painful.
Major side effects of droperidol and how to treat?
Torsades de pointe from prolonged QT interval: magnesium, isoproterenol, pacing
Neuroleptic malignant syndrome: cool patient, supportive care, consider dantrolene and bromocriptine.
Mid-systolic click followed by late systolic murmur
Mitral valve prolapse
What is pulse pressure? What are causes of narrow or wide pulse pressure?
Difference between systolic and diastolic blood pressure (normally 30-40 mmHg), it is proportional to stroke volume and inversely proportional to the compliance of the aorta. Low pulse pressure (hypovolemia, cardiogenic shock, aortic stenosis, tamponade). Wide pulse pressure (exercise, aortic regurgitation, anemia, atherosclerosis, distributive shock like sepsis, pregnancy, thyrotoxicosis, increased ICP)
serotonin syndrome treatment
stop offending agent, supportive care, treat hyperthermia and autonomic instability, cyproheptadine (antihistamine and serotonin antagonist)
What’s the mechanism of meperidine’s antishivering properties?
kappa opioid receptor agonism .
Pharmacological prophylaxis and treatment of post-operative shivering
prophylaxis: tramadol, ondansetron
treatment: meperidine, clonidine (0.15 mg IV), tramadol (1 mg/kg IV)
Intraoperative serum glucose goals
Treat for glucose > 200 mg/dL (to prevent osmotic diuresis which can lead to hypovolemia and lactic acidosis, impaired wound healing), keep glucose between 110-180 mg/dL but if neuro or ICU setting than keep glucose < 110 mg/dL
Major adverse effect of metformin
lactic acidosis, discontinue metformin at least 24 hours before surgery, restart metformin 48-72 hours after surgery
How high do fresh gas flows need to be to completely eliminate CO2 rebreathing?
30-45 L/min
If you are in the middle of ACLS and you are told that DNR/DNI was just signed by power of attorney, what do you do?
Continue resuscitation efforts
After a code/resuscitation efforts are called to stop, what do you do about the endotracheal tube?
Leave permanent documentation to prove that ETT is in the trachea, do a CXR.
How do you treat opioid induced pruritis?
anti-histamines. ondansetron if neuraxial narcotic given
what are causes of metabolic acidosis?
anion gap (increase acid): methanol, uremia, DKA, lactic acidosis, ethanol, salicylates non-anion gap (loss of bicarb): hyperchloremia from NS, acetazolamide, renal tubular acidosis, diarrhea, ostomies. Normal anion gap is 8-16 mmol/L
Lactate in LR is converted by liver into what?
bicarbonate, thus LR can cause alkalosis or be used to correct metabolic acidosis
Definition of pulmonary hypertension (pHTN) in terms of mean PA pressures
mPAP > 25 mmHg at rest or mPAP > 30 mmHg with exercise
Mechanism of ACE inhibitors
Prevent conversion of angiotensin I to angiotensin II which disrupts the renin-angiotensin-aldosterone system, thus resulting in vasodilation and decreased aldosterone leading to less sodium reabsorption and less potassium excretion
mechanism of glyburide
sulfonylurea, causes increase in intracellular calcium in the pancreatic beta cell which stimulates insulin release
Benefits of off pump CABG?
No need to induce hypothermia, less blood loss, less arrhythmias, less risk of intraop awareness, avoid problems associated with pump like SIRS, platelet dysfunction, renal dysfunction, use less heparin (half the normal dose of 300 u/kg), shorter ICU stay, fast track extubation
Reasons to convert from off pump to on pump CABG
1) Cannot maintain MAP > 50 mmHg on max doses of vasopressors
2) malignant arrhythmia
3) ST elevations > 2 mm
4) surgical emergency like laceration or dissection
Patient has hypotension of BP 60/40, why is HR unchanged?
1) patient on beta blocker
2) severe MI
3) error in BP measurement
Patient has hypotension, CVP 20, dPAP 18, wedge 22, what is going on?
tamponade
What sensory level do you need for TURP or vaginal delivery or hip surgery
T10
What type of sympathetic block is used to treat pelvic pain caused by cervical cancer?
inferior hypogastric plexus block
Is BNP an accurate reflection of heart failure? How does the value affect your anesthetic plan?
Yes, the higher the BNP, the worse the heart failure (BNP>300 mild, BNP>600 moderate, BNP>1000 severe), so if severe, I would want invasive lines to help manage hemodynamics.
Most sensitive tool to detect myocardial ischemia
TEE. 3 markers of ischemia seen with TEE.
1) most sensitive marker is reduction of the normal degree of systolic wall thickening
2) most recognizable sign is reduction in movement of the ventricular wall toward the center of the ventricle
3) wall motion abnormalities
When do you restart anti-depressants after surgery?
Restart ASAP
Intraoperative goals for COPD patient
Prefer regional to GA to avoid airway manipulation, prevent hyperinflation and barotrauma (long I:E, low peak pressure, low tidal volume, permissive hypercapnea), be aware of possibility of bronchospasm and atelectasis and pulmonary edema and pneumothorax
top 3 drugs that induce lupus erythematosus
hydralazine, procainamide, isoniazid
What are complications with enteral feeding?
aspiration, diarrhea (intolerance to composition of formula, lactose intolerance), constipation, infection
Causes of extremely prolonged spinal anesthetic
spinal cord injury, hematoma, tetracaine was accidentally used and can last 2-6 hrs vs 1-3 hrs with bupivacaine, no esterase in CSF to metabolize tetracaine.
Do volatile anesthetics cause memory loss?
Yes, postoperative cognitive dysfunction (decline in memory and executive functions) can happen with regional as well as GA. Risk factors include increased age, increased surgery duration, major operations, cardiac, pre-existing cognitive decline, intraoperative complications.
Anesthetic goals for cerebral aneurysm coiling case?
No sudden changes in transmural pressure (MAP-ICP), use pre induction arterial line, need GA to control ventilation and keep patient still, balance use of heparin (slowly titrate or ask surgeon to use heparin-coated catheters) with risk of bleeding, prevent vasospasm (triple H therapy, tx=nimodipine, balloon angioplasty only if artery is large enough, at least 1.5mm), recognize headache postop may be caused by coiling stretching the artery
No time limit for LMA, but what are risks of prolonged LMA use more than 2-3 hours?
hypoventilation, hypercarbia, patient fatigues
what cervical level do you perform a stellate ganglion block?
C6, to avoid vertebral artery puncture and pneumothorax at lower levels, 15 cc of 0.5% bupiv injected caudally so it travels toward T1, causes Horner’s syndrome (ptosis, anhidrosis, miosis)
what dose of local anesthetic do you use for a caudal block?
It is a volume dependent block, so depends on what sensory level you want to block. With 0.25% bupiv, T6 = 1 cc/kg, T10 = 0.5 cc/kg, 0.1 cc/segment/year of age. Find sacral hiatus
Risk factors for uterine atony
retained products, a long labor, high parity, macrosomia, polyhydramnios, excessive oxytocin augmentation during labor, and chorioamnionitis.
Contraindications for ECT
absolute: pheo, MI < 3mo, CVA < 1mo.
relative: increased ICP, cerebral aneurysm
Symptoms and treatment of cholinergic crisis
SLUDGE-BBB (salivation, lacrimation, urination, diarrhea, GI problems, emesis, bronchospasm, bradycardia). Treatment: pralidoxime (reactivates acetylcholinesterase), atropine (anti-muscarinic)
Why is neuraxial technique not contraindicated for HIV patient?
CNS involvement occurs early in course of HIV infection, neuraxial technique doesn’t change immune function or viral load
Indications and contraindications for placing intraosseous access
Indications (any medications infused through central line can be given via IO): failure to gain IV access in a resuscitation or life-threatening situation.
Contraindications: Use on side of fractured bones (compartment syndrome risk), overlying site infection, site of previous attempts, osteogenesis imperfecta, osteoporosis
an accurate sampling of mixed venous blood must be drawn from what part of the circulation?
the PA port of the Swan-Ganz catheter.
anesthetic considerations with a transplanted heart
no autonomic or somatic innervation, lack of vagal innervation causes baseline heart rate to be 100-120, reflex slowing of the heart rate doesn’t occur, use phenylephrine or isoproterenol to treat hypotension, immunocompromised, use ketamine for induction.
Disadvantages of PEEP
decrease preload, increase ICP, increased dead space, increased pulmonary vascular resistance (exacerbates right to left shunt), impaired CO2 elimination
