TrueLearn ITE Flashcards
- What does Bupivacaine do to the heart?
a. Blocks sodium-gated channels which leads to delayed repolarization and arrhythmias
- What is the effect of tobacco use on the oxyhemoblogin curve?
a. Shift left (decrease oxygen perfusion)
- What is most effective treatment for neuraxial opioid-induced pruritus?
Nalbuphine
What causes persistent fetal circulation in neonate?
Acidosis and hypoxia which cause increased pulmonary vascular resistance and pulmonary hypertension and persistence of right to left shunt.
What is Milrinone’s effect?
Increased inotropy and cardiac output while also decreasing pulmonary and systemic vascular resistance.
What is preferred pharmacologic treatment for atropine resistant bradycardia?
Epinephrine
What is second line pressor in septic shock, after Norepinephrine?
Epinephrine
A dot on the left of a MIGET graph represents what?
Pure shunt
What is key feature of MIGET graph for COPD/asthma?
No pure shunt
In bilateral carotid endarterectomy care must be taken with opioids, why?
Because carotid body denervation can happen. If it does central chemoreceptors solely respond to hypoxia and acidosis. Opioids blunt this and severe respiratory depression can occur.
How should bronchospasm be initially treated?
Hand ventilation with 100% FiO2 and deepening of anesthesia
What is mechanism of action of terbutaline? Effect?
Beta 2 agonist. Causes bronchial smooth muscle relaxation and bronchodilation
What is the primary effect of furosemide in the acute CHF?
Decreases venous resistance thereby decreasing mean systemic pressure
Redistribution of most anesthetic drugs occurs to where?
Skeletal muscle
What does hypothermia decrease?
Oxygen consumption, CO, respiratory effort, drug clearance, insulin secretion, clotting/platelet function, immune response, P50
How do you treat seizures in LAST (local anesthetic systemic toxicity)?
Benzos (Versed)
What is the hepatic arterial buffer response?
Hepatic artery vasodilation in response to reduced portal venous flow
What can happen after large bolus of dexmedetomidine?
Hypertension
A sharp rightward deflection of spirometry at end of pressure-volume loop is indicative of what?
Pulmonary overdistension
What two lung parameters are unchanged in obesity?
Closing capacity (volume at which small airways begin to close) and residual volume
What is the key unique physiology in patients with hypoplastic left heart palliated with the Fontan procedure?
Passive pulmonary blood flow
What are the 5 primary causes of hypoxemia?
Decreased PO2. Hypoventilation. V/Q mismatch. Impaired diffusion. Right to left shunt.
What are three reasons for increased incidence of aspiration pneumonitis in obstetric patients?
- high incidence difficult airway 2. Lower gastric fluid pH 3. Increased intraabdominal pressure
Name 4 drugs with low hepatic extraction ratio
Diazepam. Methadone. Rocuronium. Thiopental.
What is the respiratory quotient?
Ratio of CO2 produced to O2 consumed during metabolism
What is the affect of Sch on lower esophageal sphincter tone in pregnancy?
It increased to tone and decreases risk of aspiration
What is the venous admixture equation? (“shunt equation”)
Qs/Qt= CcO2-CaO2/Cc02-CvO2
Up until what post-conceptual age is it prudent to monitor a neonate overnight after general anesthesia?
60 weeks
Three requirements to prevent rebreathing in traditional circle circuit system?
- A unidirectional valve must be positioned between the patient and both the inspiratory and expiratory limbs
- Fresh gas flow cannot come into the circle system between the patient and the expiratory valve
- The APL valve cannot be positioned between the patient and the inspiratory valve
What is the shortcut for calculating the volume of liquid volatile anesthetic consumed in one hour?
ml/hr=3FGF(L/min) % anesthetic vapor
What is the distance relationship between arterial line transducers and blood pressure?
10 cm change results in 7.5 mmHg change
What is Henry’s Law?
Dalton/s Law?
Henry: Concentration of gas dissolved in a solution is directly proportional to the partial pressure
Dalton: The total pressure of a gas is equal to the sum of the partial pressures of individual gasses.
What’s the quick way to approximate the volume remaining in an O2 tank?
3:1 rule. So if full, 2000 psi then about 625 L
At what serum levels does hypermagnesemia cause respiratory depression?
At what levels will QRS become widened?
15-20 mg/dL
(cardiac): 5-10 mg/dL
What are the effect of PEEP on hemodynamics? In systolic HF?
Increases Intrathoracic pressure thereby increasing right ventricular afterload. This decreases preload which can lead to hypotension in normovolemic without heart failure.
In heart failure preload is excessive. So PEEP improves CO and decreases LVEDP.
What are two side effects of Oxytocin?
Hypotension (vasodilation) and hyponatremia (hyponatremia 2/2 antidiuretic effect)
What is the most common complication of hyperbaric oxygen therapy?
Middle ear pressure equalization. (Pain, edema, bleeding, rupture)
What induction agent should be avoided in patients with history PONV?
Etomidate
What type of ETT with most likely prevent airway fire?
Aluminum (metal)
Why should paralytics be avoided in patients with anterior mediastinal mass?
Relaxation of skeletal muscle could lead to airway collapse.
Describe respiratory changes in pregnancy. Increase/decrease?
Decrease: TLC, FRC. VC unchanged. RR unchanged. All else (capacities and ventilation (ie: MV)) increased.
Patient with mitral regurg and pulmonary edema following inferior MI. First line treatment?
Sodium nitroprusside. As an arterial vasodilator it will decrease afterload and reduce regurgitant flow. Milrinone may also be a good choice.
Describe cardiovascular effects in NORMOTENSIVE morbidly obese patient
increased blood volume leading to increased CO and DECREASED SVR.
Note: eventually increase Angiotensin-Renin and sympathetic nervous system will lead in increase BP.
List risk factors for difficult bag-mask ventilation
BMI > 26 Beard Age > 55 Edentulous Snoring
Also Mallampati III-IV, limited mandibular protrusion, mouth opening < 3cm, TM distance < 6 cm
Vent settings for utilizing PPV
Controlled ventilation, TV > 7-8 ml/kg, no PEEP
In an adult what anesthetic is most common cause of perioperative anaphylaxis?
Rocuronium (neuromuscular blocking agents)
What factors decrease evoked potentials in neuromonitoring?
volatile anesthetics, nitrous oxide, anemia, ischemia, hypoxia
How is MH transmitted genetically? What is the diagnostic test?
Autosomal dominant.
CHCT. Caffeine/halothane contracture test. Muscle biopsy exposed to ryanodine receptor agonists (caffeine and halothane) and strength of contracture measured.
When should Metformin be discontinued preoperatively?
Acute renal failure or when acute renal insufficiency is high risk (contrast dye)
How does CO change during labor?
Increases 15% in latent labor, 30% in active labor, and 45% in expulsive phase.
Additional 10-25% increase with contractions
In a patient with emergency surgery and significant risk factors for aspiration, which medication (class and two examples) can be given for prophylaxis?
H2 receptor antagonists.
Ranitidine
Famotidine
What two factors cause shedding of endothelial glycocalyx?
ANP and hypervolemia
What physical characteristics affect respiration in neonates?
Pliable rib cage causing retractions
Lower lung compliance but increased chest wall compliance
Immature intercostal musculature
Less type 1 muscle in diaphragm
What are the 4 T’s of the HIT scoring system?
- Thrombocytopenia
- Timing of reduced platelet count
- Thrombus
- oTher causes ruled out
In kids, what is the premedication dose of IM Ketamine?
2-5 mg/kg
What is the mechanism of action of Enoxaparin?
LMWH, inhibits Fator Xa
Which neuromuscular blocking agent is primarily eliminated by the kidney?
Pancuronium
What is the initial treatment for symptomatic sever hypermagnesemia? (hypotension)
Calcium gluconate or calcium chloride
What is treatment for SVT in WPW?
Procainamide
What class of medication must be avoided in pheochromocytoma?
Beta specific Beta-blockers (Metoprolol), Because unopposed alpha agonism will worsen hypertension
What are the side effects of Gabapentin?
Nausea Sedation Nystagmus Ataxia Peripheral Edema
What is induction agent of choice in acute intermittent porphyria?
Fentanyl
What are the 5 goals of anesthetic management of HCOM?
- Reduce myocardial contractility
- Maintain or increase SVR
- Increase preload and CO
- Maintain low-normal heart rate
- Treat arrhythmia
What EKG change is characteristic for hypocalcemia?
Prolonged QT
What is mechanism of action of isoproterenol?
Non-selective beta-agonist
What blood product carries the lowest risk of TRALI?
PRBCs
What are the two groups of local anesthetics? How to remember this?
Aminoamides and aminoesters.
Aminoamides have two “I’s”:
Bupivacaine, Lidocaine, Mepivacaine
What is Lithium’s effect of NDNBD’s?
Potentiates paralytics by interfering with prejunctional neuron action potential transmission
What are three ways to manage intraoperative pulmonary hypertension?
Nitroglycerine (vasodilators), PDE-3 inhibitors, Nitrous Oxide
What is most commonly used epidural test dose?
3 ml of 1.5% Lidocaine with 1:200,000 epinephrine
A complete injury to unilateral recurrent laryngeal nerve would result in what vocal cord position?
Paramedian position of affected side (both adductor and abductor segments of nerve injured)
What are the ACC/AHA guidelines for days to wait for nonurgent surgery after stent placement?
PCA: 14 days
BMS: 30 days
DES: 365 days
What 6 parameters comprise the Revised Cardiac Risk Index (RCRI)?
- Procedural Risk
- Hx of CVA
- Hx ischemic heart disease
- Insulin dependent DM
- CKD with Cr > 2.0
- Hx of CHF
A disc herniation at L4-L5 affects what nerve?
L4
What are 5 common characteristics associated with hypoplastic left heart syndrome?
- ASD
- Stenoic or atretic mitral and aortic valves
- Hypoplastic left ventricle
- hypoplastic ascending aorta
- PDA
Hypoxic pulmonary vasoconstriction (HPV) is attenuated by what? (6 drugs)
- Inhaled volatiles
- ACE
- ARBs
- NO
- PDE inhibitors
- prostacyclin
What elements make up VACTERL association?
Vertebral abnormalities imperforate Anus Congenital heart disease TracheoEsophogeal fistula Renal abnormalities Limb abnormalities
ESRD on dialysis, why is surgical hemostasis difficult?
Impaired platelet aggregation 2/2 uremia
What statistical term represents the accuracy with which a sample represents the population?
Standard error of the mean
What anesthetic agents must be avoided in carcinoid syndrome?
Agents that release Histamine (Succs, Mivacurium, Atracurium, Tubocurarine)
How does altitude affect volatile anesthetic delivery/
Delivered concentration is increased
Partial pressure is unchanged
What color nail polish is least likely to affect pulse ox?
Red
Volatile anesthetics attenuate what cerebral blood flow response most?
Perfusion pressure (autoregulation)
How much does cerebral metabolic rate decrease per decrease in temperature?
6-7% reduction per degree C reduction
What are general platelet cutoffs for surgery?
50,000 for general surgery
100,000 for neurosurgery
In patient with peripartum cardiomyopathy, what is general recommendation for delivery and anesthesia?
Vaginal delivery with epidural anesthesia
Postoperative pulmonary complications are likely to be reduced after smoking cessation of what duration?
4-8 weeks
What is ratio of TOF to % receptors blocked?
1 twitch indicates >90% suppression.
2 twitches indicate 80-90% suppression.
3 twitches indicate 70-80% suppression.
4 twitches indicate 65-75% suppression.
What T4:T1 TOF ratio is considered sufficient?
0.75