Hepatic, Renal and Endocrine Anesthesia Flashcards

A diabetic patient on metformin presents for elective surgery. Metformin should be withheld perioperatively primarily to prevent:

Answer: Lactic acidosis if contrast or renal dysfunction occurs perioperatively

Metformin is associated with lactic acidosis risk when renal clearance is impaired (e.g., from contrast nephropathy, fluid shifts, or hypoperfusion) and is typically withheld 24–48 hours perioperatively.

Which intraoperative blood glucose target is recommended for most surgical patients to balance risks of hypoglycemia and hyperglycemia?

Answer: 140–180 mg/dL

Current perioperative guidelines recommend a blood glucose target of 140–180 mg/dL, as tight control (80–110) increases hypoglycemia risk without improving outcomes in most surgical patients.

Thyroid storm (thyrotoxic crisis) can be precipitated by surgery and presents with which combination of features?

Answer: Hyperthermia, tachycardia, and high-output cardiac failure

Thyroid storm is characterized by extreme hyperthermia, tachyarrhythmia, high-output heart failure, and altered mental status due to massive thyroid hormone release.

In a patient with a known pheochromocytoma scheduled for adrenalectomy, adequate preoperative alpha-blockade is confirmed by:

Answer: Orthostatic hypotension and nasal congestion indicating alpha-receptor blockade

Adequate phenoxybenzamine or doxazosin alpha-blockade is demonstrated by postural hypotension (>20 mmHg drop) and symptoms like nasal congestion indicating peripheral vasodilation.

Which anesthetic drug should be AVOIDED in patients with adrenal insufficiency (Addison's disease) because it inhibits cortisol synthesis?

Answer: Etomidate

Etomidate inhibits 11-beta-hydroxylase, the enzyme required for cortisol synthesis, and can cause adrenal suppression lasting 24+ hours even after a single induction dose.

Diabetes insipidus after transsphenoidal pituitary surgery is characterized by which laboratory finding?

Answer: High serum sodium with large volumes of dilute urine

Central diabetes insipidus causes ADH deficiency, resulting in massive production of dilute urine, volume depletion, and hypernatremia due to free water loss.