Ch 120 - Pheochromocytoma Flashcards
What are the cells called which synthesise catecholamines?
Chromaffin cells
What is the ratio of epinephrine:norepinephine in cats and dogs
Cats: 70%epi, 30% norepi
Dogs: 60% epi, 40% norepi
What is the rate limiting enzyme for the production of epinephrine
Tyrosine hydroxylase
Is there atrophy of the contralateral adrenal gland with a phaechromocytoma
No
What is the most specific test for phaeochromocytoma?
Urine creatine:normetanephrine ratio
What kind of drug is phenoxybenzamine?
Alpha-adrenergic receptor blocker
The use of phenoxybenzamine preoperatively has decreased perioperative mortality rate from what to what?
48 - 13%
What medication can be considered if persistently tachycardic pre-operatively?
Atenolol or propanolol (beta-adrenergic antagonist)
What medication can be used for intra-operative arterial hypertension?
Phentolamine (short acting alpha agonist) or nitroprusside (direct vasodilator)
What percentage of phaeochromocytomas invade the cava?
35-55%
(11-16% with adrenocortical tumours)
What is the perioperative mortality rate for phaeochromocytomas?
9-47%
What is the MST with medical management for phaeochromocytomas?
17.8m