Endocrinology

Question 1

Which of the following patients undergoing a total colectomy will MOST LIKELY benefit from supplemental perioperative stress-dose steroids?

Answer 1

Patients receiving more than 20 mg/day of prednisone for greater than 3 weeks are at high risk for hypothalamic-pituitary-adrenal axis (HPAA) suppression and should be considered for perioperative stress-dose steroids. Intermediate risk patients may benefit from a preoperative evaluation of HPAA suppression.

Question 2

Which of the following signs or symptoms is MOST LIKELY to be found in a patient with hyperparathyroidism?

Answer 2

Patients with hyperparathyroidism may have unpredictable responses to neuromuscular blocking agents due to competing effects of preoperative skeletal muscle weakness and hypercalcemia mediated resistance to neuromuscular blocking agents. Thus, close and frequent perioperative monitoring is recommended.

TrueLearn Insight : Hypercalcemia leads to “stones, bones, abdominal groans, thrones, and psychiatric overtones”
Stones: kidney stones
Bones: bone-related complications
Groans: gastrointestinal symptoms
Thrones: polyuria, constipation (throne = toilet)
Overtones: central nervous system effects

Question 3

Severe hypercalcemia should be initially managed by which of the following?

Answer 3

Hypercalcemia can result in a variety of signs and symptoms ranging from mild anorexia and irritability to heart block, coma, and death. Immediate temporizing therapy of clinically significant hypercalcemia includes volume replacement with normal saline and loop diuretics.

Question 4

Which of the following hormones is LEAST likely to directly influence potassium homeostasis?

Answer 4

Many hormones play vital roles in electrolyte homeostasis. Aldosterone and cortisol promote renal potassium secretion leading to losses through the urine. Insulin and thyroid hormones enhance cellular potassium uptake.

Question 5

Which of the following is LEAST likely to be seen in a patient with hyperthyroidism?

Answer 5

Excessive thyroid hormones cause a variety of symptoms, depending on the body system:
General: weight loss, heat intolerance, and warm, moist skin
Cardiovascular: tachycardia, atrial fibrillation, and congestive heart failure
Neurologic: nervousness, tremor, and hyperactive reflexes
Gastrointestinal: diarrhea
Musculoskeletal: muscle weakness
Hematologic: anemia and thrombocytopenia

Question 6

A patient with hyperparathyroidism secondary to an overactive parathyroid nodule is scheduled for parathyroidectomy. Lab results show moderate hypercalcemia. What changes, if any, should be made with regard to neuromuscular blockade for airway securement?

Answer 6

Hypercalcemia antagonizes the effects of non-depolarizing neuromuscular blockers, and therefore higher doses may be required to obtain the desired effect.

Question 7

You are caring for a 6-year-old female with spina bifida who is undergoing open reduction internal fixation of her left humerus. The patient had a standard induction with propofol and placement of a laryngeal mask airway. The patient develops severe hypotension, tachycardia, and cutaneous flushing 15 minutes following induction. Which of the following is NOT an initial appropriate therapy in this patient?

Answer 7

Any patient with spina bifida should be considered high risk for latex allergy. These patients have often had multiple surgeries with possible latex exposure. If an anaphylactic reaction does occur, prompt treatment is required to avoid cardiovascular collapse. This includes an IV fluid bolus, epinephrine, prompt removal of possible latex equipment, and cessation of anesthetic agents. A tryptase level should be drawn to assist in the diagnosis.

Question 8

A patient has developed hypoparathyroidism after a total thyroidectomy. Which of the following is the first step in the management of this patient?

Answer 8

PTH is secreted in response to low serum calcium and acts in several ways to increase the calcium concentration in the blood. One way it does this is by increasing the renal production of Vitamin D, which then works on the GI tract to increase calcium absorption. Hypoparathyroidism is therefore treated with supplementation of both calcium and vitamin D.

TrueLearn Insight : Parathyroid hormone, PTH, is a “Phosphate Trashing Hormone” resulting in low levels of phosphate in hyperparathyroidism.

Question 9

A patient with diabetes mellitus is undergoing coronary artery bypass grafting. Which of the following is NOT associated with perioperative hyperglycemia?

Answer 9

Perioperative hyperglycemia has been associated with immunosuppression, increased infections, osmotic diuresis, delayed wound healing, delayed gastric emptying, sympatho-adrenergic stimulation, and increased mortality. In addition, it reduces skin graft success, exacerbates brain, spinal cord, and renal damage by ischemia, worsens neurologic outcomes in traumatic head injuries, and is associated with postoperative cognitive dysfunction following CABG.

Question 10

Which of the following is MOST likely associated with a new diagnosis of primary hyperthyroidism?

Answer 10

Primary hyperthyroidism is characterized by elevated T3, T4 (free and total), and thyroid hormone binding ratio, and a low or normal TSH. Thyroid hormone binding ratio (formerly known as resin T3 uptake) is used to determine the amount of free T4 that is circulating, which can change depending on the quantity of thyroid binding globulin (TBG).

Question 11

The effects of both insulin and glucagon are mediated in hepatocytes via which of the following second messenger molecules?

Answer 11

Insulin and glucagon utilize the cAMP signaling pathway during signal transduction within the hepatocyte. Insulin decreases intracellular cAMP whereas glucagon increases this second messenger.

Question 12

Which of the following is a common laboratory derangement seen in patients on chronic corticosteroid therapy?

Answer 12

Laboratory abnormalities associated with corticosteroid use include: leukocytosis, polycythemia, hyperglycemia, mild hypernatremia, hypokalemia, and increased urinary calcium. id. Corticosteroid-induced hypercalciuria is the mechanism behind several side effects of the medication, including osteoporosis, nephrocalcinosis, and nephrolithiasis.

Question 13

The plasma concentration of which of the following hormones will MOST likely decrease in the first few hours following an acute stressor such as surgery?

Answer 13

In situations of acute stress, such as surgery, triiodothyronine (T3) depression occurs within hours.

Question 14

Which of the following processes is impaired by glucagon?

Answer 14

lucagon raises blood glucose levels by stimulating glycogenolysis and gluconeogenesis. Glucagon also stimulates lipolysis and impairs glycolysis, which results in increased availability of substrates for gluconeogenesis.

TrueLearn Insight : Glucagon also has cardiac inotropic and chronotropic effects. Similar to catecholamines, it enhances the activation of adenyl cyclase in cardiac myocytes, but its effects are not blocked by β-blockers. The typical dose is 1-5 mg IV, followed by an infusion.

Question 15

A 28-year-old otherwise healthy patient with Graves’ disease is admitted to the hospital for management of thyrotoxicosis. Which treatment is the LEAST appropriate treatment option for this patient?

Answer 15

Multiple long-term treatment options exist for patients with hyperthyroidism or thyrotoxicosis. These include thyrostatic medications such as methimazole and propylthiouracil, ablation of the gland by radioactive iodine, and surgical removal of the thyroid gland. Other symptomatic treatments such as propranolol are also available, but they do not treat the underlying disease process and are only to be used in the short-term while other treatment is being pursued. The use of radioactive iodine alone may initially worsen symptoms of thyrotoxicosis.

Question 16

A 26-year-old type I diabetic is scheduled for elective excision of a skin lesion. He is given a dose of insulin preoperatively for moderately elevated blood glucose. Which of the following will MOST likely occur following insulin administration?

Answer 16

Insulin exerts a variety of anabolic effects throughout the body including increased fatty acid synthesis within the liver

Question 17

Insulin is given to treat a patient with severe hyperkalemia. What is the mechanism by which this works?

Answer 17

Insulin causes intracellular shift of potassium with glucose and can be used to treat hyperkalemia.

Question 18

An allergy to which of the following foods is LEAST likely to be associated with an allergy to latex?

Answer 18

Health care workers, atopic individuals, and those with allergies to certain foods (avocados, bananas, chestnuts, kiwi fruit, papayas, potatoes, tomatoes) have an increased incidence of latex allergy.

Question 19

Which of the following cell types is MOST dependent on insulin for glucose uptake?

Answer 19

Hepatocytes, most immune cells, erythrocytes, and brain neurons utilize insulin-independent glucose transporters for the majority of their glucose uptake. Cardiac myocytes depend on insulin for the majority of the cells’ glucose uptake.

Question 20

A patient with insulin-dependent diabetes arrives at the hospital for emergency surgery and has a preoperative blood glucose of 300 mg/dL. The patient had been found on the floor prior to ambulance transport and the family believes the patient has been on the ground for approximately 18 hours. Which of the following is the BEST management option?

Answer 20

In emergency surgeries, the patient’s history may be incomplete. In a known insulin-dependent diabetic due for surgery, peri-operative glucose management is crucial. Due to pharmacokinetic predictability and dosing titratability, intravenous insulin with close glucose monitoring is the most appropriate therapy in an emergency setting.

Question 21

A patient presents to the Emergency Department with altered mental status. He is minimally responsive and his physical exam is notable for non-pitting edema in his legs. His vital signs are significant for hypotension, hypoventilation, and hypothermia. Which is the MOST likely diagnosis for this patient?

Answer 21

Myxedema coma is an extreme form of hypothyroidism that is classically characterized by altered mental status, hypothermia, and non-pitting edema. It is most commonly seen in patients with chronic hypothyroidism in the setting of a physiologic stressor such as infection and is considered a life threatening emergency.

TrueLearn Insight : Myxedema coma is rare, and most commonly presents to anesthesiologists in the postoperative period after a trigger such as infection, exposure to cold temperatures, and excessive sedation and analgesic medications.

Question 22

Which of the following is LEAST appropriate for the anesthetic management of a patient with Addison disease?

Answer 22

Etomidate inhibits the synthesis of cortisol transiently in all patients and should be avoided in patients with adrenal insufficiency. Etomidate specifically inhibits 11β-hydroxylase and 17α-hydroxylase in the cortisol pathway in a reversible dose-dependent fashion.

Question 23

Which of the following is the most appropriate INITIAL treatment for a patient with symptomatic hypercalcemia?

Answer 23

Initial treatment for hypercalcemia should be aimed at volume correction. With restoration of the patient’s fluid deficit furosemide can be used to decrease calcium levels.

TrueLearn Insight : Calcium is an amazing inotrope particularly in the setting of hypocalcemia. An IV bolus dose of 7 mg/kg may last as long as 10-15 minutes. It is especially useful when separating from cardiopulmonary bypass (CPB). Calcium can reverse hypotension due to hyperkalemia secondary to cardioplegia as well as correct the dilutional hypocalcemic effect of CPB.

Question 24

A 59-year-old male is seen in pre-operative clinic for a right shoulder surgery. He has a history of type 2 diabetes mellitus. His glucose is controlled with metformin. Which of the following is the primary mechanism of action of metformin?

Answer 24

Metformin acts to decrease glucose levels by decreasing hepatic gluconeogenesis and increasing insulin sensitivity.

Question 25

Which of the following is MOST accurate regarding the pre-operative management of metformin?

Answer 25

Metformin may be continued through the perioperative period. Evidence shows that the occurrence of lactic acidosis is rare.