Hepatic, Renal and Endocrine Anesthesia Flashcards

A patient with hepatic encephalopathy grade III requires emergency surgery. Which agent is MOST appropriate for induction?

Answer: Propofol 1-2 mg/kg with cautious titration

Propofol, carefully titrated to effect, is preferred in hepatic encephalopathy as it reduces cerebral metabolic rate without significantly worsening encephalopathy; ketamine raises ICP and thiopental/etomidate are less favorable.

Which coagulation factor is synthesized exclusively in the liver and has the shortest half-life, making it the most sensitive marker of acute hepatic synthetic failure?

Answer: Factor VII

Factor VII has the shortest half-life (~4-6 hours) and is exclusively hepatically synthesized, making PT/INR the most sensitive early indicator of acute liver failure.

A patient on chronic lithium therapy for bipolar disorder presents for elective surgery. What is the primary anesthetic concern regarding renal function?

Answer: Lithium-induced nephrogenic diabetes insipidus causes hypovolemia and hypernatremia

Chronic lithium causes nephrogenic diabetes insipidus by antagonizing ADH in collecting ducts, leading to polyuria, dehydration, and hypernatremia that must be corrected before anesthesia.

During laparoscopic cholecystectomy in a patient with Child-Pugh C cirrhosis, which hemodynamic pattern is characteristic of the hepatorenal syndrome type 1 that may develop perioperatively?

Answer: Low SVR, high CO, marked renal vasoconstriction

HRS type 1 occurs in the context of cirrhotic hyperdynamic circulation (low SVR, high CO) with paradoxical intense renal vasoconstriction, causing rapid deterioration of renal function.

A patient with a known pheochromocytoma is inadequately alpha-blocked prior to emergency appendectomy. Intraoperative hypertensive crisis occurs. What is the FIRST-LINE treatment?

Answer: IV phentolamine 1-5 mg bolus titrated

Phentolamine, a short-acting non-selective alpha-blocker, is first-line for acute hypertensive crises from pheochromocytoma; beta-blockers like labetalol must never be given before adequate alpha-blockade as they worsen hypertension.

Which inhalational anesthetic is MOST associated with fluoride-mediated nephrotoxicity, particularly after prolonged exposure or in patients with pre-existing renal disease?

Answer: Methoxyflurane

Methoxyflurane undergoes extensive hepatic defluorination producing serum fluoride concentrations above the nephrotoxic threshold (>50 µmol/L), historically causing high-output renal failure; sevoflurane's defluorination is modest and renal impact minimal.

A 58-year-old with diabetic nephropathy (eGFR 18 mL/min) requires lower limb revascularization. Postoperative potassium rises to 6.8 mEq/L with ECG changes. What is the MOST immediate treatment?

Answer: IV calcium gluconate 10 mL of 10% solution

IV calcium gluconate is the most immediate treatment for hyperkalemia with ECG changes as it stabilizes the myocardial membrane within 1-3 minutes, though it does not lower serum potassium.