Endocrine and Metabolic Systems

Question 1

How does hyperthyroidism affect cardiac muscle?

Answer 1

increased beta-1 receptor density

Question 2

How is propranolol useful in treating hyperthyroidism?

Answer 2

reducing adrenergic symptoms

blocking peripheral conversion of T4 to T3

Question 3

How does insulin promote glucose tranport into cells?

Answer 3

it causes translocation of the Glut4 receptor to the cell surface

Question 4

How does insulin treat hyperkalemia?

Answer 4

it increases the activity of the Na-K ATPase

Question 5

How does insulin affect protein synthesis?

Answer 5

it promotes amino acid uptake into cells, increasing protein synthesis

Question 6

What is the downstream signalling pathway for the insulin receptor?

Answer 6

tyrosine kinase receptors

activation of PKB

production of IP3

Question 7

How large is the typical fluid deficit is patients with hyperosmolar hyperglycemic state (HHS)? Why?

Answer 7

8-10 L due to osmotic diuresis

Question 8

What must occur along with insulin deficiency to result in DKA?

Answer 8

upregulation of counter-regulatory hormones that oppose insulin’s action (i.e., promote glycogenolysis, gluconeogenesis, and lipolysis)

Question 9

How do propylthiouracil and methimazole differ in treating hyperthyroidism?

Answer 9

• both inhibit thyroperoxidase centrally, blocking production of thyroid hormone
• only PTU blocks peripheral conversion of T3 to T4

Question 10

What are the post-op concerns for total thyroidectomy?

Answer 10

• Rebleeding -> tracheal deviation
• Recurrent laryngeal nerve palsy
  
  • unilateral -> hoarseness
  • bilateral -> stridor, aphonia
• Hypoparathyroidism -> hypocalcemia -> laryngospasm

Question 11

What are the anesthetic concerns of untreated hypothyroidism?

Answer 11

• decreased cardiac output
• effusions -> tamponade, restrictive lung disease
• hypothermia
• decreased drug biotransformation
• hyponatremia

Question 12

What is Cushing’s syndrome? Anesthetic concerns?

Answer 12

Excess ACTH causing hyperglycemia, HTN from hypervolemia, and hypokalemic alkalosis

Question 13

What regimen is used in the pre-op management of pheochromocytoma?

Answer 13

1. alpha blockade w/ phenoxybenzamine
2. volume expansion
3. beta blocker AFTER alpha blocker

Question 14

At what point in surgery during removal of a pheochromocytoma will a patient often become hypotensive?

Answer 14

after ligation of the adrenal vein

Question 15

What syndromes are associated with pheochromocytoma?

Answer 15

MEN IIa and IIb

Von Hippel-Lindau

neurofibromatosis

Question 16

What are the vasoactive substances released by carcinoid tumors?

Answer 16

serotonin

histamine

kallikrein

Question 17

What are the cardiac complications of carcinoid syndrome?

Answer 17

fibrotic right heart endocardium

tricuspid regurgitation

pulmonic stenosis

Question 18

What drug can decrease the release of carcinoid mediators?

Answer 18

octreotide (a.k.a., synthetic somatostatin)

Question 19

What are the most common causes of intra-operative anaphylaxis?

Answer 19

1. muscle relaxants
2. antibiotics
3. latex

Question 20

What is the difference between anaphylaxis and anaphylactoid reactions?

Answer 20

anaphylaxis is IgE-mediated, while anaphylactoid reactions are not

*both are severe, more common in atopic individuals, and result in mast cell degranulation w/ elevated serum tryptase levels

Question 21

What food allergies are commonly associated with latex allergy?

Answer 21

banana

pineapple

avocado

chestnut

kiwi fruit

mango

passionfruit

fig

strawberry

soy

Question 22

What are the standard treatments for anaphylaxis?

Answer 22

epinephrine

fluids

H1 blockers (diphenhydramine)

H2 blockers (famotidine)

steroids (hydrocortisone)

Question 23

What can be given to a patient with anaphylaxis who is beta blocked and, thus, poorly responsive to epinephrine?

Answer 23

glucagon

Question 24

What percentage of people with penicillin allergies will have a cross-reaction to cephalosporins?

Answer 24

<2%

Question 25

What is the incidence of atlanto-axial instability in patients with RA?

Answer 25

25%