Pheochromocytoma: preop preparation

Advanced, Clinical - Endocrine/Metabolic, Organ-Based and Clinical Sciences

Intro (Why does it Matter?)

Approximately 25% to 50% of hospital deaths in patients with pheochromocytoma occur during induction of anesthesia or during operative procedures for other causes.

Symptoms

Excessive sweating; headache; hypertension; orthostatic hypotension; previous hypertensive or arrhythmic response to induction of anesthesia or to abdominal examination; paroxysmal attacks of sweating, headache, tachycardia, and hypertension; glucose intolerance; polycythemia; weight loss; and psychological abnormalities.

Diagnosis

Most specific test: Vanillylmandelic acid excretion

Most sensitive: abdominal CT

Preoperative treatment

α-Adrenergic receptor blockade with prazosin or phenoxybenzamine restores plasma volume by counteracting the vasoconstrictive effects of high levels of catecholamines

β-Adrenergic receptor blockade with propranolol is suggested for patients who have persistent arrhythmias or tachycardia because these conditions can be precipitated or aggravated by α-adrenergic receptor blockade. β-Adrenergic receptor blockade should not be used without concomitant α-adrenergic receptor blockade lest the vasoconstrictive effects of the latter go unopposed and thereby increase the risk for dangerous hypertension.

Pheochromocytoma Preoperative Treatment and GoalsTreatment Regimen

  • At least 10-14 days (there is no rush to remove these slow growing tumors)
  • Alpha blockade (phenoxybenzamine) in all patients
  • Beta blockade (propranolol) if arrhythmias/tachycardia persist

Goals on DOS

  • No reading > 165/90 within 48 hours of surgery, including 1 hour of stressful readings (ex. PACU, SAS)
  • Orthostatic hypotension should not be lower than 80/45
  • No EKG ST or T changes
  • PVCs less than one every 5 minutes

98%

Answered correctly

2016

Year asked

88%

Answered correctly

2012

Year asked

84%

Answered correctly

2009

Year asked