Anesthesia and Pheochromocytoma
Clinical Manifestations
- catecholamine-secreting tumor
- cells from embryonic neural crest (chromaffin tissue)
- 1 of 1,000 hypertension patients
- most unilateral and benign
- 10-15% malignant
- 10-15% bilateral or extra-adrenal
- Signs
- paroxysmal headache
- hypertension
- sweating
- palpitations
- rarely presents with unexpected intraoprative hypertension and tachycardia
Anesthetic Considerations
- Preoperative considerations
- evaluate
- arterial blood pressure
- orthostatic blood pressure and heart rate changes
- evidence of myocardial ischemia
- adrenergic blockade
- alpha blockade
- phenoxybenzamine
- helps correct
- volume deficit
- hypertension
- hyperglycema
- consider additional beta blockade after alpha blockade if
- no cardiomyopathy (check ECHO)
- persistent tachycardia
- persistent dysrhythmia
- alpha blockade
- volume replacement
- chronic hypovolemia
- decrease in RBC mass and plasma volume
- aided by alpha-adrenergic blockade
- may unmask underlying anemia
- evaluate
- Operating room considerations
- arterial line
- good IV access
- monitor urinary output
- central venous pressure (CVP) monitoring
- maybe pulmonary artery catheter (e.g. evidence of catecholamine cardiomyopathy)
- intubate deep
- treat intraop hypertension
- phentolamine
- specific adrenergic blocker
- nitroprusside
- rapid onset
- short duration of action
- familiarity
- nicardipine
- phentolamine
- best avoid
- after tumor resection
- hypotension
- hypovolemia
- persistent adrenergic blockade
- abrupt drop in circulating catecholamine level
- fluid resuscitation based on
- arterial blood pressure
- urinary output
- CVP
- pulmonary capillary occlusion pressure
- surgical bleeding
- third-space losses
- adrenergic agent infusion occasionally necessary
- phenylephrine
- norepinephrine
- hypotension
- Postoperative
- hypertension may indicate
- occult tumor(s) or
- volume overload
- hypertension may indicate
