Endocrine 1 - Diabetes, Thyroid, and OB

Question 1

Where is the endogenous peptide called Insulin synthesized?

Answer 1

pancreatic beta cells

Question 2

What are three functions of Insulin?

Answer 2

facilitate transport of glucose and potassium into cells
shift metabolism toward storage (glycogen, lipid synthesis)
stimulates protein synthesis (anabolism)

Question 3

How much insulin per hour is secreted when the body is at rest?
How much insulin per day is secreted in response to food, stress, corticosteroids, and other stimuli?

Answer 3

1 unit/hr at rest

40-50 units/day when stressed

Question 4

Which pancreatic cell when stimulated DECREASES insulin production?
Which pancreatic cell when stimulated INCREASES insulin production?

Answer 4

Alpha DECREASES
Beta INCREASES (parasympathetic stim also increases insulin)

Question 5

Why is it more effective to administer a 1-2 unit/hr continuous infusion of insulin rather than a large bolus?

Answer 5

Insulin receptors get saturated at low insulin concentrations.

Question 6

Why does insulin have a sustained effect of 30-60 mins?

Answer 6

Insulin is tightly bound to receptors

Question 7

What is the half-time of Insulin?

Answer 7

5-10 mins

Question 8

What is the biggest risk when administering exogenous insulin?

Answer 8

Hypoglycemia

Question 9

What is the Pre-op management recommendation for your patient who takes insulin daily?

Answer 9

No short-acting insulin on day of surgery
a partial (half) dose of long-acting insulin
implanted pumps should either be discontinued or on continuous infusion

Question 10

How much does 1 unit of exogenous insulin lower plasma glucose by in a normal adult?

Answer 10

25-30mg/dL

Question 11

How quickly does 1 unit of IV insulin start to work, what is the peak effect, and how long does 1 unit last?

Answer 11

onset: 10 mins, Peak: 15-30 mins, duration: 30-60 mins

Question 12

What is the recommended starting rate of infusion for insulin?

Answer 12

0.1 units/kg/hr or Plasma Glucose (mg/dL)/150

Question 13

What pancreatic cells secrete Glucagon?

Answer 13

alpha cells

Question 14

What stimuli trigger glucagon secretion?

Answer 14

hypoglycemia, stress, trauma, cortisol, sepsis

Question 15

What is mobilized into the systemic circulation when glucagon is stimulated?

Answer 15

glucose, fatty acids, amino acids, and increased liver production of glucose

Question 16

What drug is not a catecholamine but acts like one by increasing cAMP, myocardial contractility, SV, HR and works even in the presence of Beta-blockade?

Answer 16

Glucagon

Question 17

What are some side effects of glucagon?

Answer 17

nausea/vomiting and hypoglycemia

Question 18

What is the elimination half-time of glucagon?

Answer 18

3-6 mins

Question 19

What are some examples of Sulfonylureas?

Answer 19

GLIpizIDE (Glucotrol), GLYburIDE(Micronase), GLImepirIDE (Amaryl)

Question 20

What class of drugs is the first line treatment for Type II diabetes?

Answer 20

Sulfonylureas

Question 21

What is the mechanism of action of Sulfonylureas?

Answer 21

increases beta cell activity leading to more insulin secretion

Question 22

What class of drug does metformin (glucophage) fall in?

Answer 22

Biguanides (oral hypoglycemic agents)

Question 23

What is the mechanism of action of metformin?

Answer 23

inhibits hepatic gluconeogenesis by preventing the convertion of lactate into glucose

Question 24

What are some risks associated with metformin?

Answer 24

lactic acidosis and low risk for hypoglycemia

Question 25

True or false: Metformin should be held on the day of surgery?

Answer 25

True, but lacks supporting evidence

Question 26

What is the mechanism of action of Thiazolidinediones (TZDs) (ex: Actos)?

Answer 26

decreases insulin resistance at the skeletal muscle/adipose tissue making the body more sensitive to insulin

Question 27

What is the mechanism of action of Sitagliptin (Januvia)?

Answer 27

inhibits DPP-4 which increases insulin release and decreases hepatic glucose production.

Question 28

Should your patient who has been fasting for several hours before surgery be given the okay to take their oral hypoglycemic agent on the day of surgery?

Answer 28

No, but taking their med the day of surgery depends on how long its been without caloric intake. Daily regimen can often be maintained if first surgery of the day.