ITE CA2 General 3 Flashcards
What happens to potassium in met alkalosis
Potassium repletion is important for treatment of the metabolic alkalosis since the alkalosis causes hypokalemia. Recall that K+ is driven into cells and exchanged for intracellular H+ in an attempt to buffer the alkalosis. In an attempt to correct the hypokalemia, an H-K-ATPase in the renal collecting tubules then reabsorbs K+ in exchange for secreting H+, thus worsening the alkalosis. Potassium repletion therefore improves an alkalosis by reversing these two processes. First, as the intracellular K+ deficit is restored, H+ moves out of the cells as the K+ moves in. Second, potassium repletion decreases the H-K-ATPase activity and allows bicarbonate, and not H+, to be excreted in the urine.
MTHFR deficiency avoid what drug
Nitrous oxide (C) should be avoided in patients with MTHFR deficiency
Etomidate side effect mechanism
Etomidate (B) is an induction agent that is relatively hemodynamically stable. However etomidate has been shown to inhibit 11-beta-hydroxylase. 11-beta-hydroxylase is used by the adrenal glands to produce corticosteroids, because of this etomidate has been linked to adrenal suppression and insufficiency. It should be avoided in septic patients.
Following neostigmine administration, a dose of succinylcholine will
Following neostigmine administration, a dose of succinylcholine will result in an increased duration of phase I blockade when compared to the duration of action of succinylcholine administered alone. Phase I augmentation lasts about 30 minutes on average.
In the hemodynamically unstable patient with SVT, what is the best treatment
In the hemodynamically unstable patient with SVT, synchronized cardioversion is the best treatment. For regular narrow complex tachycardia, a starting dose of 50-100 J is appropriate. For irregular narrow complex tachycardia, 120-200 J of biphasic or 200 J of monophasic is used. Unsynchronized cardioversion is the best treatment for irregular wide complex tachycardia (like ventricular fibrillation).
For regular narrow complex tachycardia, a starting dose of ____ J is appropriate.
For irregular narrow complex tachycardia, _____ J of biphasic or ____ J of monophasic is used.
________________ is the best treatment for irregular wide complex tachycardia (like ventricular fibrillation).
In the hemodynamically unstable patient with SVT, synchronized cardioversion is the best treatment. For regular narrow complex tachycardia, a starting dose of 50-100 J is appropriate. For irregular narrow complex tachycardia, 120-200 J of biphasic or 200 J of monophasic is used. Unsynchronized cardioversion is the best treatment for irregular wide complex tachycardia (like ventricular fibrillation).
What lab check before place epidural if patient on heparin for more than 5 days
Patients receiving heparin for more than five days should have a platelet count checked prior to epidural placement or catheter removal. ASRA guidelines recommend waiting 4-6 hours before epidural placement in patients receiving 5000 U subcutaneous heparin BID or TID.
C diff testing
A C. difficile bacterial antigen enzyme immunoassay (EIA) can rapidly detect the presence of the bacteria, although asymptomatic carriers will also be positive.
Follow-up to a positive antigen EIA is typically done with the gold standard C. difficile cell culture cytotoxin assay.
The latter is highly sensitive and specific for C. difficile infection but does not provide results quickly.
A C. difficile toxin A/B EIA has moderately high sensitivity and specificity, produces results quickly, and may be used as a solitary test.
carbon monoxide shift oxy hemo curve
left
Bohr effect
The Bohr effect states that oxygen is more readily released from hemoglobin in the face of acidosis or hypercarbia.
ionized form of weak base
HB+
unionized form of weak base
B
ionized or unionized lidocaine crosses lipid bilayer
unionized
the higher the pH of a solution, the ____ of a weak base such as lidocaine will exist in its unionized fraction.
the higher the pH of a solution, the more of a weak base such as lidocaine will exist in its unionized fraction.
permanent pacemaker, lower extremity surgery, not pacer dependent, what do with pacer?
This patient has a permanent pacemaker (PPM) and it should be confirmed to be functioning properly prior to proceeding. If a recent interrogation report is not available, a qualified practitioner should interrogate the device. She is having a lower extremity surgery which has a low risk of electromagnetic interference (EMI), and her ECG indicates that she is not pacemaker dependent. As such, there is not a need to reprogram her device into an asynchronous mode prior to proceeding.
Most common reasons for discharge delay after ambulatory surgery
Pain and postoperative nausea and vomiting are the two most common reasons for discharge delay.
Sign of bladder perf during TURP
When TURP procedures are done under spinal anesthesia up to T10 level and not deeply sedated, bladder perforation can be recognized by abdominal pain (may be referred to shoulder or chest) (and TURP syndrome can be recognized by CNS symptoms).
Test indicated prior to robot assisted radical prostatectomy
Cerebrovascular imaging should be obtained prior to a RARP in patients with an increased risk for intracranial aneurysm. The required steep Trendelenburg positioning significantly increases the risk of cerebral aneurysm rupture.
Marfan, Ehlers-Danlos, polycycstic kidney disease ass’d with aneurysms
TIVA pancreatitis?
Propofol is a good antiemetic agent, but theoretically can cause or worsen pancreatitis and therefore should be avoided or limited in situations where pancreatitis is likely. The mechanism of propofol induced pancreatitis is thought to be related to hypertriglyceridemia.
Acute mountain sickness Pathophys Adaptation Severe manifestations Presentation typical prophylaxis treatment
Ascent to high altitudes leads to hypoxia and a resultant respiratory alkalosis.
However, the body is able to acutely adapt over 2-3 days and reequilibrates PaO2, PaCO2, arterial pH, and CSF pH primarily by changes in ventilatory drive and increased bicarbonate excretion.
However, a person may experience AMS, high altitude pulm edema HAPE, and/or high altitude cerebral edema HACE prior to achieving an equilibrium driven by hypoxic ventilatory drive.
AMS presents with non-specific symptoms including headache, nausea, vomiting, insomnia, and malaise.
Prophylaxis can be accomplished with staged ascent and acetazolamide.
Treatment includes descent, supplemental oxygen, and dexamethasone. More severe manifestations include HAPE and HACE, both of which should be treated with descent and supplemental oxygen.
Nitrous oxide administration after intraocular injection of
Air
Sulfur hexafluoride
other perfluoropropane
Nitrous oxide administration should be avoided for five days after intraocular air injection, 10 days after sulfur hexafluoride injection, or 30-90 days or longer after other perfluoropropane injection
Ischemic optic neuritis presentation
ION following surgery generally presents with painless visual loss, visual field deficits, and sluggish pupils.
Negative pressure pulmonary edema
incidence
Risks
Negative pressure pulmonary edema has an incidence of 0.05-0.1% in all general anesthetics.
Risk increases to 4% if airway obstruction occurs in a spontaneously breathing patient. Other risks include young age, male gender, physical fitness, and HEENT surgery.
Methanol poisoning
sources
treatment
Methanol poisoning can occur following ingestion of substances including paint thinners, antifreeze, windshield washer fluid, and improperly distilled alcohol.
Hepatic alcohol dehydrogenase converts methanol to highly toxic formaldehyde and formic acid. Treatment of acute methanol poisoning consists of supportive care (securing an airway, maintaining hemodynamic stability, treating metabolic acidosis), prevention of the conversion of methanol to toxic metabolites (ethanol or fomepizole), and in severe cases, rapid elimination of methanol and its metabolites via hemodialysis.
Difficult airway exam
On examination, risk factors for difficult laryngoscopy include
increasing Mallampati score (strongest association with class III-IV),
inter-incisor distance less than 4 to 4.5 cm,
thyromental distance less than 6 to 6.5 cm,
neck movement less than 80 degrees,
inability to prognath the mandible,
obesity of more than 110 kg or BMI of more than 25 to 30,
neck circumference of greater than 43 cm,
sternomental distance of less than 12.5 to 13.5 cm, and
reduced submental compliance.
The AFFERENT nerve impulses of carotid sinus baroreceptors are transmitted by
The AFFERENT nerve impulses of carotid sinus baroreceptors are transmitted by the Hering’s nerves to the glossopharyngeal nerve (CN IX)
Carotid sinus baroreceptor stimulation
Carotid sinus baroreceptor stimulation leads to direct sympathetic inhibition and indirect predominance of vagal tone on cardiac performance.
Things that increase LES tone
acetylcholine antacids anticholinesterases alpha agonists cholinergics gastrin histamine metaclopramide metoprolol pancreatic polypeptide serotonin succinylcholine
Early onset adult VAP bugs
first 72 hours of intubation
Early onset adult VAP is typically due to antibiotic-sensitive flora
(Methicillin-sensitive Staphylococcus aureus (MSSA),
H. influenzae,
S. pneumoniae, and
Proteus, Klebsiella, and Enterobacter species) and does not typically affect morbidity and mortality.
Late-onset VAP bugs
Late-onset VAP is associated with a fairly high mortality rate and is caused by more virulent organisms such as
methicillin-resistant Staphylococcus aureus (MRSA),
Pseudomonas aeruginosa, and
Acinetobacter species.
Least stable factors in FFP
Factors V and VIII are the least stable factors in FFP. Factor VIII is produced in the vascular endothelium and sinusoidal cells of the liver. Von Willebrand factor serves as a carrier molecule for factor VIII, which is ultimately activated by IIa.
Where is factor VIII produced
what carries it
what activates it
Factors V and VIII are the least stable factors in FFP.
Factor VIII is produced in the vascular endothelium and sinusoidal cells of the liver. Von Willebrand factor serves as a carrier molecule for factor VIII, which is ultimately activated by IIa.
Hepatopulmonary syndrome (HPS) is characterized by the triad of
Hepatopulmonary syndrome (HPS) is characterized by the triad of liver dysfunction, unexplained hypoxemia, and intrapulmonary vascular dilations. One of the unique features of this syndrome is orthodeoxia, which is increased dyspnea when transitioning from the supine to upright position.
Orthodeoxia
Hepatopulmonary syndrome (HPS) is characterized by the triad of liver dysfunction, unexplained hypoxemia, and intrapulmonary vascular dilations. One of the unique features of this syndrome is orthodeoxia, which is increased dyspnea when transitioning from the supine to upright position.
How many mg of fibrinogen in 1 unit cryo
Ten units of cryo raise 70 kg person fibrinogen by how much
Cryoprecipitate contains about 200 mg of product in each unit. Ten units of cryoprecipitate will typically raise a 70kg patient’s fibrinogen by 70 mg/dL.
Electrolyte abnormalities in alcoholic patients include:
Electrolyte abnormalities in alcoholic patients include: hypocalcemia, hypomagnesemia, hypophosphatemia, and hypoglycemia.
hemostatic abnormalities in cirrhosis
Thrombocytopenia is a well-known feature of cirrhosis. Other hemostatic abnormalities in cirrhosis include a decrease in pro- and anti-coagulants (potentially causing bleeding or thrombotic complications) and low-grade fibrinolysis.
TrueLearn Insight : Since INR does not necessarily reflect bleeding propensity in cirrhosis, products such as fresh frozen plasma (FFP) should not be given simply to “correct” an INR number. Studies such as the thromboelastogram (TEG) can help better determine bleeding vs clotting ability.
cirrhosis hemodynamics
Cirrhosis hemodynamics are characterized by a hyperdynamic state, with increased cardiac output and low peripheral vascular resistance.
volatile effect on hypoxic pulm vasoconstriction
Increasing volatile anesthetics (greater than 1 MAC) will inhibit hypoxic pulmonary vasoconstriction
Clinical signs and symptoms of carcinoid syndrome
how diagnosed
Clinical signs and symptoms of carcinoid syndrome include bronchoconstriction, episodic cutaneous flushing, abdominal pain, diarrhea, hemodynamic instability, hepatomegaly, hyperglycemia, and dysthymia.
Also right sided heart disease
These tumors can be diagnosed by the presence of excessive amounts of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in urine
renal changes with age
Changes to the renal system in the geriatric population include a decreasing renal mass, blood flow, creatinine clearance, and ability to effectively dilute and concentrate urine placing them at risk for prolonged medication effects and dehydration.
Note: Serum creatinine remains the same because of reduced muscle mass
MH inheritance
autosomal dominant
3 muscle diseases which confer increased susceptibility to MH
central core disease,
multiminicore disease, and
King-Denborough syndrome.
Most people with MH susceptibility do not have a specific phenotype, but there are three muscle diseases which confer increased susceptibility to MH, namely central core disease, multiminicore disease, and King-Denborough syndrome. Many other muscle diseases have been suggested to confer MH susceptibility, but only these three are supported by the evidence. Note succinylcholine and volatile anesthetics are avoided in Duchenne muscular dystrophy because of the risk of rhabdomyolysis, not because of an increased susceptibility to MH.
Hepatic arterial buffer
what happens and by what key player
With a functioning hepatic arterial buffer response, hepatic arterial tone is modulated by portal venous flow, via adenosine, in order to maintain hepatic perfusion.
A reduction of blood flow in the portal vein leads to an increase of adenosine in the liver and subsequent local arteriole dilation and an increase in blood flow from the hepatic artery.
Effect on hepatic blood flow
Glucagon
Angiotensin II
Vasopressin
Glucagon causes dose-dependent hepatic arterial vasodilation. Angiotensin II causes vasoconstriction of hepatic arterial and portal venous systems. Vasopressin increases splanchnic vasoconstriction while decreasing resistance to portal venous flow.
Meralgia paresthetica
Meralgia paresthetica is a mononeuropathy of the lateral femoral cutaneous nerve, a purely sensory nerve.
Retractor-related nerve injury may involve the brachial plexus (sternotomy), femoral nerve (gynecologic surgery), or lateral femoral cutaneous nerve (pregnancy or use of pelvic retractors).
Typical hemodynamics in ECT
During electroconvulsive therapy, there is a brief initial parasympathetic surge followed by a sympathetic response. This is manifested by a brief episode of bradycardia followed by significant tachycardia and hypertension.
The hallmarks of autonomic hyperreflexia are
The hallmarks of autonomic hyperreflexia are hypertension and reflexive bradycardia
The Meyer-Overton correlation related the potency of anesthetics with solubility in
The Meyer-Overton correlation related the potency of anesthetics with solubility in olive oil.
CMS regulations state that
Every patient that receives anesthesia must have the following:
Every patient that receives anesthesia must have the following:
1) A pre-anesthesia evaluation when general, regional, or monitored anesthesia care is planned. This must be performed by a physician, dentist, oral surgeon, certified registered nurse anesthetist, anesthesiologist’s assistant, or podiatrist.
2) This evaluation must be completed and documented within 48 hours immediately prior to any surgery requiring anesthesia services, however some elements may be performed prior but under no circumstances should they be performed more than 30 days prior to surgery.
3) This evaluation must have certain criteria – review of medical and surgical history, medications, allergies, notation of anesthesia risk, identification of problems if relevant, and development of a plan.
4) A post anesthesia evaluation completed by personnel who is qualified to administer anesthesia no later than 48 hours after surgery. This should not be performed until the patient is sufficiently recovered from the anesthesia administered. This is not possible for all patients and notation stating the patient was unable to participate is adequate. The requirements list that the post-anesthetic evaluation must be performed by an anesthesiologist, other doctor of medicine/osteopathy (who is not an anesthesiologist), certified nurse anesthetists, anesthesia assistant, dentist, oral surgeon, or podiatrist.
Meningomyelocele is commonly associated with
Meningomyelocele is commonly associated with Chiari II malformation and care must be taken to ensure no neurologic deficits or other congenital anomalies exist that may alter anesthetic management.
Also renal abnormalities
22q 11 deletion
DiGeorge Syndrome which includes the “CATCH - 22” conglomeration of findings: cardiac abnormalities, abnormal facies, thymic aplasia, cleft palate, and hypocalcemia.
possible complications of tumescent lidocaine liposuction
Patients should be monitored postoperatively to assess for possible circulatory overload and pulmonary edema as well as several other potential serious complications (e.g. acute heart failure, body cavity perforation, fat emboli, pulmonary emboli, and local anesthetic toxicity). If pulmonary edema is suspected, initial treatment options include diuretics, head of bed elevation and/or reverse Trendelenburg positioning, supplemental FiO2, and possibly noninvasive positive pressure ventilation (e.g. CPAP). Severe pulmonary edema leading to respiratory distress should prompt intubation and mechanical ventilation with PEEP. Usually, pulmonary edema associated with tumescent liposuction is mild, self-limited, and resolves without invasive supportive care.
algorithm for bronchospasm
Anesthesia management of bronchospasm should have a stepwise approach:
- Use hand assisted ventilation to assess compliance
- Confirm bronchoconstriction and assure that no other causes are contributing
- The patient should be placed on 100% oxygen
- Deepen anesthetic: increase volatile agents and consider intravenous ketamine
- Administration of beta-2-agonist
- Administration of intravenous epinephrine (use small doses to start)
- Consider high dose steroids
- Magnesium sulfate 1 to 2 grams
- Consider Heliox if patient will tolerate lower oxygen concentrations
Transplanted lungs differences
Transplanted lungs are denervated and cough reflex and mucociliary function will likely be impaired. Lymphatic drainage is also absent and may affect fluid clearance during subsequent anesthetics.
normal values CVP: PCWP: CI: SVR:
CVP: 2-6 mmHg
PCWP: 6-12 mmHg
CI: 2.5-4 L/min/m2
SVR: 800-1200 dynes*sec/cm5
Bone cement implantation syndrome
Bone cement implantation syndrome is characterized by hypoxia, hypotension, cardiac dysrhythmias, and increased pulmonary vascular resistance after methyl methacrylate implantation.
The definitive mechanism is unknown
The preoptic anterior hypothalamus
The preoptic anterior hypothalamus plays a key role in temperature homeostasis and thermoregulation.
The medial tuberal hypothalamus
The medial tuberal hypothalamus contains neurons that extend into the posterior pituitary and secrete vasopressin and oxytocin.
paraventricular and supraoptic nuclei are in medial tuberal
TRALI mechanism
antibodies in the donor blood bind to the recipient’s leukocytes, which then adhere to the vascular capillary bed in the pulmonary circulation. This causes damage and extravasation of intravascular fluid. TRALI results in a non-cardiogenic pulmonary edema that usually occurs within 6 hours of transfusion. TRALI is characterized by respiratory distress/failure with bilateral infiltrates seen on CXR. The incidence of TRALI is 1:5000 transfusions and occurs more often in blood donated by multiparous females.
non-hemolytic febrile reaction mechanism
native host antibodies bind to donor leukocytes (HLA antigens) in the transfused blood. The antibodies cause cell lysis which allows for a cytokine release. The released cytokines include IL-1 and TNF-alpha, which increase the hypothalamic temperature set point causing shivering and fever. Red blood cell-leukocyte reduction and premedication with acetaminophen can help prevent a non-hemolytic febrile reaction.
mechanism by which transfusion-related immunomodulation (TRIM) occurs
Transfusion of soluble leukocyte mediators is the mechanism by which transfusion-related immunomodulation (TRIM) occurs
Latex-induced allergic reactions result from a type ___
what mediated
how long after exposure
Latex-induced allergic reactions result from a type I IgE-mediated antibody response, typically having a delayed onset longer than 30 minutes after exposure to latex.
botox mechanism
The Clostridium botulinum toxin cleaves SNARE proteins which prevents the release of ACh from storage vesicles into the NMJ. This results in significant muscle weakness or a flaccid paralysis.
detection of HIT
Detection of antiplatelet factor 4 antibodies is commonly used to diagnose HIT. Antiplatelet factor 4 detection has a high sensitivity for HIT. The serotonin release assay has a high specificity for HIT.
HIT mechanism
Heparin induced thrombocytopenia (HIT) is an antibody mediated process in which the patient develops antibodies against platelet factor 4 (PF4). Platelet factor 4 is exposed when heparin binds to platelets
HIT typically develops 4-10 days following the initiation of heparin therapy. The platelet count of a patient with HIT often drops by more than 50% of pre-heparin values. Additionally, HIT is a hypercoagulable condition associated with DVTs and occasionally arterial thrombosis. The 5 T’s of HIT are: timing, thrombocytopenia, type of heparin, thrombosis, and type of patient (surgical > medical).
main mechanism for patient heat loss in the operating room following initial redistribution of heat.
Redistribution of heat from the core to the periphery is the largest contributor to the initial reduction in core temperature during general anesthesia. Prevention or reduction of this can be accomplished by pre-warming the patient’s extremities prior to the induction of general anesthesia. Radiation is the main mechanism for patient heat loss in the operating room following this initial redistribution of heat.
The acute discontinuation of TPN is associated with
The acute discontinuation of TPN is associated with hypoglycemia.
respiratory quotients and what it means is being used
For patients on TPN, a respiratory quotient of 0.7 is consistent with pure fat oxidation and results in fat accumulation in the liver. A quotient of 1.0 is consistent with pure carbohydrate oxidation with subsequent respiratory distress.
phantom pain risk factors
prevalence
how long it lasts
Phantom sensations (non-painful sensations) are nearly universal among amputees, and phantom pain is also very common with a prevalence of 65-85% of amputees.
In most studies, phantom pain was independent of age, gender, side, previous health status, and cause of amputation (civilian versus traumatic).
Phantom pain is not only very prevalent, but also long-lasting and difficult to treat. In one study, 60% of amputees had phantom pain two years after the amputation. Although it will usually decrease in severity and intensity within the first 6 months after amputation, phantom pain will typically become stable after 6 months and is extremely difficult to treat.
The one thing found to be a risk factor is preamputation pain, with many amputees indicating that phantom pain resembled preamputation pain, at least initially. Based on this finding, several studies have focused on treating pre-amputation pain as a way to try to prevent the development of phantom pain. Some (but not all) studies showed that epidural analgesia for 2-3 days pre-amputation decreased the incidence of phantom pain.
moving on the frank-starling curve
The Frank-Starling curve is shifted down and to the right with increased afterload or decreased inotropy (e.g. systolic heart failure). Decreased afterload and increased inotropy with shift the curve up and to the left. Increased end diastolic volume for a given state of inotropy and afterload will shift right along the curve. Decreases in end diastolic volume (e.g. diuretics) will cause a left shift along the curve.
what causes vagal response to pneumoperitoneum
acute stretching of the peritoneum
most common blood product to cause transfusion-associated sepsis
Transfusion-associated sepsis is the third leading cause of transfusion-related deaths in the United States and is most commonly caused by bacterial infection from contaminated platelets. Unlike other blood products, platelets are stored at room temperature which leads to increased bacterial growth.
Blood transfusion in IgA deficient patients
IgA deficient patients are at risk for anaphylactic response to IgA antigens in donor blood, as they may have anti-IgA antibodies from prior blood exposure or pregnancy. To avoid this reaction, these patients should receive washed red blood cells or blood from IgA deficient donors.
Since plasma cannot be washed of IgA, it must come from a deficient donor.
hemolytic transfusion reaction pathway
The complement system is activated in a hemolytic transfusion reaction that typically occurs when ABO incompatible blood is given.
Croup other name
laryngotracheobronchitis
more important to prevent burn in MRI
straight wires or towel between wires and skin
straight wires
airway neurofibromatosis
In patients with neurofibromatosis, careful airway planning may be required. Neurofibromas may be present in the airway and depending on their size may lead to complete airway collapse with induction. Neurofibromas are highly vascularized lesions that can bleed profusely if disrupted. Extreme care must be taken when present in the airway because damage may result in bleeding which is difficult to tamponade and may make visualization of the larynx impossible.
Carotid body pathway
The carotid bodies are one of the most highly vascular areas of the body, and these chemosensitive cells are exquisitely sensitive to changes in arterial oxygen consumption. At PaO2 values of around 55-60 mmHg, these cells generate nerve impulses that are transmitted to the central respiratory centers in the medulla via the sinus nerve of Hering, which is an afferent branch of CN IX, also known as the glossopharyngeal nerve.
carotid and aortic bodies detect what
Both the carotid and aortic bodies are areas of chemosensitive cells which primarily detect decreases in arterial partial pressures of oxygen
(secondary CO2)
aortic body pathway and effects
In contrast to carotid bodies, signals that originate in the aortic body primarily cause downstream circulatory effects. While aortic bodies also detect changes in arterial PaO2, they transmit afferent nerve impulses via CN X, the vagus nerve. The end-organs which these signals are transmitted to include the heart, peripheral vasculature, adrenal glands, and the lungs themselves. Detection of arterial hypoxia (PaO2 less than about 60 mmHg) will result in bradycardia, hypertension, bronchoconstriction, and eventual steroid release from the adrenal glands. While the aortic bodies generate a parasympathetic response to hypoxia, decreasing oxygen consumption throughout the body, prolonged hypoxia will stimulate central chemoreceptors and will result in sympathetic activation.
where in the brain is the central respiratory center
medulla
medulla respiratory center is sensitive to what
dissolved CO2
two groups of neurons in medulla and what they do
The ventral respiratory group is active during expiration. Meanwhile, the dorsal respiratory group is active during inspiration and is regulated by the pons.
The sites at which core temperature can be measured
The sites at which core temperature can be measured are the pulmonary artery, distal aspect of the esophagus, tympanic membrane, and nasopharynx
how many acetylcholine molecules does it take to activate the nAChR on the neuromuscular postjuntional membrane
How many succ molecules?
Two separate acetylcholine molecules or a single succinylcholine molecule must bind to the two alpha subunits of the nicotinic acetylcholine receptor for activation
chylothorax from central line on left or right
Thoracic duct injury should be suspected if the patient develops ipsilateral supraclavicular swelling or unilateral (very rarely, bilateral) pleural effusions after left-sided central venous catheterization. The pleural effusion will most likely exhibit as gradually worsening dyspnea and pleuritic chest pain.
The classic clinical findings in cardiogenic shock include
The classic clinical findings in cardiogenic shock include
(1) low cardiac output with jugular venous distension,
(2) hypotension with peripheral and pulmonary venous congestion,
(3) peripheral vasoconstriction,
(4) cool extremities,
(5) poor urine output, and
(6) altered mental status.
requirements for MAC anesthesia
MAC requires anesthesia physician supervision with postoperative care and the provider must be qualified and prepared to convert to GA, if necessary. Spontaneous ventilation may be impaired and require intervention for a patent airway.
Conn's syndrome what is it what electrolyte derrangements acidosis vs alkalosis presentation anesthetic management
Conn’s syndrome is primary hyperaldosteronism. It results in
elevated serum Na+,
reduced serum K+, and
reduced renin activity.
Patients typically present with increased blood pressure, fatigue, and a hypokalemic metabolic alkalosis.
Anesthetic management includes preoperative K+ repletion and volume management. Intraoperatively, hyperventilation should be avoided and cortisol may need to be administered if both adrenal glands are being excised.
Aldosterone
where does it function and
what ions go where
Aldosterone is the mineralocorticoid produced in the zona glomerulosa of the adrenal cortex. It functions in the distal renal tubules by absorbing Na+ ions in exchange for urinary loss of K+ and H+ ions. The effect of aldosterone is volume expansion as H2O follows Na+ ions.
sepsis vs septic shock
According to the Sepsis-3 guidelines, sepsis should be defined as “life-threatening organ dysfunction caused by a dysregulated host response to infection.” Under this definition, all cases of sepsis should be considered, by definition, severe and thus, the designation of “severe sepsis” was eliminated from the diagnostic spectrum. Septic shock remains defined as a subset with “profound circulatory, cellular, and metabolic abnormalities” that are associated with greater mortality risk (approximately 40%) than sepsis alone. Under Sepsis-3, a patient with documented organ dysfunction in the setting of suspected infection should be diagnosed with sepsis.
SOFA scoring and threshold for sepsis
These patients can be identified by an increase of the “Sequential [Sepsis-related] Organ Failure Assessment” or SOFA score of 2 or more points, with each of the values in the following categories scoring 1-4 points (using the worst values in the past 24 hours):
PaO2/FiO2 ratio,
Platelet count,
Glasgow Coma Scale,
Bilirubin,
Mean arterial pressure or administration of vasopressors required,
Creatinine level.
Septic shock is defined as a diagnosis of sepsis as above with the following, in the absence of hypovolemia:
Septic shock is defined as a diagnosis of sepsis as above with the following, in the absence of hypovolemia:
vasopressor requirement to maintain mean arterial pressure of at least 65 mmHg, and
serum lactate level greater than 2 mmol/L.
(qSOFA) score in which two of the following are noted:
(qSOFA) score in which two of the following are noted:
respiratory rate of ≥ 22/min,
altered mentation, or
systolic blood pressure ≤ 100 mmHg.
How is PAO2 affected by Patm FiO2 PH2O PACO2
The alveolar gas equation is used to determine alveolar oxygen tension. PAO2 = [(Patm – PH2O) * FiO2] – (PACO2 / R). Increases in Patm and FiO2 and decreases in PH2O and PACO2 lead to increases in PAO2.
A normal A-a gradient is
and a normal a-A ratio is
By comparing the PAO2 and the PaO2 (A-a gradient and A:a ratio), a determination of oxygenation can be made. A normal A-a gradient is < 10 mm Hg, and a normal a-A ratio is >0.75.
Trendelenburg position effects
Trendelenburg position reduces FRC, TLC, lung compliance, and chest wall compliance. Abdominal contents are shifted cephalad, which may potentially relocate the end of a fixed ETT into the right mainstem bronchus.
The Trendelenburg position is associated with a rise in intrapulmonary shunt (perfusion without ventilation).
Functional residual capacity (FRC) is
Functional residual capacity (FRC) is the sum of the expiratory reserve volume (ERV) and the residual volume (RV), (FRC = ERV + RV).
For a patient failing an initial SBT,
For a patient failing an initial SBT, an appropriate and simple weaning strategy would be the continuation of daily SBTs with inspiratory pressure support.
