Ch 120 - Pheochromocytoma

Question 1

What are the cells called which synthesise catecholamines?

Answer 1

Chromaffin cells

Question 2

What is the ratio of epinephrine:norepinephine in cats and dogs

Answer 2

Cats: 70%epi, 30% norepi
Dogs: 60% epi, 40% norepi

Question 3

What is the rate limiting enzyme for the production of epinephrine

Answer 3

Tyrosine hydroxylase

Question 4

Is there atrophy of the contralateral adrenal gland with a phaechromocytoma

Answer 4

No

Question 5

What is the most specific test for phaeochromocytoma?

Answer 5

Urine creatine:normetanephrine ratio

Question 6

What kind of drug is phenoxybenzamine?

Answer 6

Alpha-adrenergic receptor blocker

Question 7

The use of phenoxybenzamine preoperatively has decreased perioperative mortality rate from what to what?

Answer 7

48 - 13%

Question 8

What medication can be considered if persistently tachycardic pre-operatively?

Answer 8

Atenolol or propanolol (beta-adrenergic antagonist)

Question 9

What medication can be used for intra-operative arterial hypertension?

Answer 9

Phentolamine (short acting alpha agonist) or nitroprusside (direct vasodilator)

Question 10

What percentage of phaeochromocytomas invade the cava?

Answer 10

35-55%
(11-16% with adrenocortical tumours)

Question 11

What is the perioperative mortality rate for phaeochromocytomas?

Answer 11

9-47%

Question 12

What is the MST with medical management for phaeochromocytomas?

Answer 12

17.8m