Once a diagnosis of Pheochromocytoma or paraganglioma is made, removal of the tumor requires medical management that involves Nephrology involvement heavily.
There are basically two arms to the preparation. One is controlling the hypertension and second is making their blood pressure salt dependent and responding to fluids when they are post op. No trials have been ever conducted on any of these approaches but from years of experience of many physicians, this works.
What agents to use for controlling the BP? - Alpha blockade first, followed by beta blockaded. Never do the reverse as it will lead to unopposed alpha and more HTN. Usually this can be started 7-12 days prior to surgery and then towards the date of the surgery, recommended high salt diet to ensure good dependence and response to fluids as the longer you have alpha blocked them, the less they will respond to pressors once the tumor is removed.
The alpha blockers of choice are:- non specific alpha blocker and longer acting Phenoxybenzamine, or specific short actings like doxazosin or terazosin. The Beta blockers used are propranolol or atenolol. Sometimes, metyrosine is used, which inhibits the catecholamine synthesis( the side effect profile- not great).
Some patients with persistent HTN, might need IV phentolamine as well pre op for 24-48 hours followed by IVF at high rates prior to surgery and very close monitoring of the HTN during surgery via anesthesia.
Two most commonly feared post op complications are:
Hypotension:- hence we try to make them fluid dependent.
Hypoglycemia:- Due to fall of catecholamine secretion and may need glucose infusion.
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