Endocrinology
In type 2 diabetes mellitus, which mechanism contributes to increased fasting glucose levels?
A. Increased peripheral glucose uptake
B. Decreased glucagon secretion
C. Increased hepatic gluconeogenesis
D. Enhanced insulin sensitivity
Answer: C. Increased hepatic gluconeogenesis
Rationale: In T2DM, insulin resistance and inappropriate glucagon secretion lead to increased hepatic glucose production, especially during fasting. This is a major driver of elevated fasting glucose.
Citation: ADA Standards of Care; Guyton & Hall
A male patient (Weight 70 kg) in the ICU with pneumonia has been relatively stable with good urine output until 8 hours ago. Over the last 8 hours, their urine output has only been 240 mL. SCr of 0.9 mg/dL has been stable for the past 3 days. What is his stage of acute kidney injury?
A. Stage 1
B. Stage 2
C. Stage 3
D. Unable to determine based on the given information.
Answer: A. Stage 1
Rationale: Staging of acute kidney injury is based on either an increase in SCr or decrease in urine output over a period of time. Since the patient had no change in SCr but a significant change in urine output. The staging for urine output is Stage 1 < 0.5 mL/kg/hr over at least 6 hours, which fit this case as they had 0.43 mL/kg/hr over 8 hours. Stage 2 is the same volume per kg/hr but must be over 12 hours making it incorrect and stage 3 is <0.3 mL/kg/hr over 12 hours or anuria for 12 hours, making it incorrect. Answer 4 is incorrect as there are enough details here to answer the question. Maccedo E, Mehta RL. Clinical approach to the diagnosis of acute kidney injury. In: Gilbert SJ, Weiner DE, Bomback AS, et al. eds. National Kidney Foundations’ Primer on Kidney Diseases, 7th ed. Philadelphia: Elsevier Saunders, 2018: 300-310.
Citation: Khwaja A. et al. KDIGO clinical practice guidelines for acute kidney injury. Nephron Clin Pract. 2012;120(4):c179-84
A 65-year-old female is treated for a prosthetic knee infection. Cultures from the joint are positive for methicillin resistant Staphylococcus aureus. Which agent should be recommended due to its ability to penetrate bacterial biofilm?
A. Linezolid
B. Oxacillin
C. Rifampin
D. Vancomycin
Answer: C. Rifampin
Rationale: Clinical practice guidelines and the medication’s pharmacodynamic activity suggest efficacy for rifampin, answer C. Rifampin has the ability to penetrate biofilm and should be initiated in infections with organisms that produce biofilm. Other antimicrobials listed are unable to penetrate bacterial biofilm.
Citation: Osmon DR, Berbari EF, Berendt AR, et al. Diagnosis and management of prosthetic joint infection: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis 2013;56(1):e1-25.
A patient presents with opioid overdose and respiratory depression. What is the initial treatment?
A. Flumazenil
B. Naloxone
C. Epinephrine
D. Atropine
B. Naloxone
Which medication class is first-line for rate control in atrial fibrillation?
A. ACE inhibitors
B. Beta-blockers
C. Nitrates
D. Statins
Correct Response:
B. Beta-blockers
Rationale: Beta-blockers slow AV nodal conduction and are first-line for rate control in atrial fibrillation.
Citation: January, C. T., et al. (2019).
2019 AHA/ACC/HRS focused update of the atrial fibrillation guideline. Journal of the American College of Cardiology, 74(1), 104–132. https://doi.org/10.1016/j.jacc.2019.01.011
Which physiologic mechanism explains polyuria in uncontrolled diabetes mellitus?
A. Increased aldosterone secretion
B. Osmotic diuresis from glucosuria
C. Decreased glomerular filtration rate
D. Increased sodium reabsorption
Answer: B. Osmotic diuresis from glucosuria
Rationale: When plasma glucose exceeds the renal threshold, glucose is excreted in the urine and pulls water with it, resulting in osmotic diuresis and polyuria. Increased aldosterone or sodium reabsorption would promote fluid retention, while decreased GFR would reduce urine output.
Citation: Guyton & Hall Textbook of Medical Physiology.
A patient complaining of significant pain upon urination was found to have nephrolithiasis. After laser oblation, the stones are identified as being calcium-phosphate stones. Which therapy could contribute to the formation of these stones?
A. Atorvastatin
B. Lithium
C. Spironolactone
D. Topiramate
Answer: D. Topiramate
Rationale: Carbonic anhydrase inhibitors, such as topiramate, act in the proximal tubule where they block resorption of sodium bicarbonate. Consequently, prolonged use of carbonic anhydrase inhibitors, such as topiramate, may lead to a hyperchloremic metabolic acidosis, in which urinary pH is increased and urinary citrate is decreased. The other agents, spironolactone, atorvastatin, and lithium, are not strongly associated with renal stones.
Citation: 1)Matlaga BR, Shah OD, Assimos DG. Drug-induced urinary calculi. Rev Urol. 2003; 5(4): 227-231. 2)Salek T, Andel I, Kurfurstova I. Topiramate induced metabolic acidosis and kidney stones - a case study. Biochem Med (Zagreb). 2017;27(2):404-410.
A 24-year-old male with newly diagnosed HIV is started on appropriate antiretroviral therapy. Labs prior to therapy were HIV viral load 560,000 copies/mL and CD4 cell count 430 cells/mm3. Which suggests a positive response to therapy at the appropriate timepoint after starting treatment?
A. HIV viral load: 55,000 copies/mL at four weeks
B. HIV viral load: 111,000 copies/mL at three months
C. CD4 cell count: 440 cells/mm3 at four weeks
D. CD4 cell count: 460 cells/mm3 at three months
Answer: A. HIV viral load: 55,000 copies/mL at four weeks
Rationale: For successful HIV antiretroviral treatment, the expectation is a 10-fold decrease in HIV viral load four weeks after initiation of therapy (answer 1 is correct). Answer 2 is incorrect because that only shows a 5-fold decrease THREE months later. CD4 counts are expected to increase by 50 cells/mm3 three months after initiation of therapy (answers 3 and 4 are incorrect).
Citation: Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in adults and adolescents living with HIV. Department of Health and Human Services. https://clinicalinfo.hiv.gov/en/guidelines (accessed 2023 Feb 4).
A 24-year-old male presents after being exposed to a pesticide while working out in the field all day. He presents with excessive salivation, lacrimation, emesis, miosis, and diaphoresis. Which toxidrome is the patient exhibiting?
A. Anticholinergic
B. Cholinergic
C. Sedative-Hypnotic
D. Serotonin Syndrome
B. Cholinergic
The answer is cholinergic. The cholinergic toxidrome is characterized by the combination of miosis, diaphoresis, excessive salivation, lacrimation and emesis The signs/symptoms of anticholinergic toxidrome include dry flushed skin, delirium, hyperthermia, tachycardia, urinary retention and hypoactive bowel sounds. The classic signs and symptoms of sedative-hypnotic are sedation, bradycardia, hypothermia and hypotension. The classic sign and symptoms of serotonin syndrome are muscle rigidity, hyperthermia, tachycardia, hypertension and tachypnea.
Citation: Levine M, Brooks DE, Truitt CA, et al. Toxicology in the ICU: Part 1: general overview and approach to treatment. Chest. 2011;140(3):795-806.
A patient with acute coronary syndrome has a history of prior stroke. Which antiplatelet agent should be avoided?
A. Clopidogrel
B. Ticagrelor
C. Prasugrel
D. Cangrelor
Answer: C. Prasugrel
Rationale: Prasugrel is contraindicated in patients with prior stroke or TIA due to increased bleeding risk.
Citation: TRITON-TIMI 38 Trial; Effient Package Insert
A patient with type 1 diabetes presents with nausea, vomiting, and abdominal pain. Labs show glucose 420 mg/dL, bicarbonate 12 mEq/L, and positive serum ketones. Which of the following is the most appropriate initial management step?
A. Start subcutaneous insulin immediately
B. Administer intravenous fluids
C. Give sodium bicarbonate
D. Start potassium-lowering therapy
Correct Response:
B. Administer intravenous fluids
Rationale: In diabetic ketoacidosis (DKA), fluid resuscitation is the first step to restore perfusion before insulin therapy.
Reference:
American Diabetes Association. (2024).
Hyperglycemic crises in diabetes: Standards of Care in Diabetes—2024. Diabetes Care, 47(Suppl. 1). https://doi.org/10.2337/dc24-S015
A patient presents with altered mental status. The patient is found to have a serum sodium of 128 mEq/L (128 mmol/L), a urine sodium of 64 mEq/L (64 mmol/L), and a urine osmolality of 430 mOsm/kg. Home medications include carbamazepine, metoprolol tartrate, furosemide, lisinopril, and zonisamide. This presentation is likely exhibiting:
A. hypovolemic hyponatremia due to furosemide
B. hypovolemic hyponatremia due to zonisamide
C. syndrome of inappropriate antidiuretic hormone secretion caused by carbamazepine
D. syndrome of inappropriate antidiuretic hormone secretion caused by lisinopril
Answer: C. Syndrome of inappropriate antidiuretic hormone secretion caused by carbamazepine
Rationale: SIADH can present with altered mentation due to fluid shifts and hyponatremia. SIADH is characterized by a serum sodium <=134 mEq/L (134 mmol/L), urine sodium >= 30 mEq/L ( 30 mmol/L), urine osmolality > 100 mOsm/kg. SIADH can be drug induced by carbamazepine. Lisinopril does not cause SIADH. While hypovolemic hyponatremia can be caused by furosemide, this would not present with an over concentrated urine osmolality. Zonisamide does not cause hypovolemic hyponatremia though it could cause SIADH.
Citation: Shepshelovich D, Schechter A, Calvarysky B, Diker-Cohen T, Rozen-Zvi B, Gafter-Gvili A. Medication-induced SIADH: distribution and characterization according to medication class. Br J Clin Pharmacol. 2017;83(8):1801-1807. doi:10.1111/bcp.13256
An adult male presents after a tuberculosis skin test was positive. The patient has not experienced any symptoms consistent with tuberculosis and chest x-ray shows no abnormal findings. Which is best for this patient?
A. No treatment is needed
B. Isoniazid and rifapentine weekly x 3 months
C. Isoniazid, rifampin, pyrazinamide, and ethambutol x 2 months, then isoniazid and rifampin x 4 months
D. Rifampin monotherapy x 9 months
Answer: C. Isoniazid and rifapentine weekly x 3 months
Rationale: The patient has latent tuberculosis based on a positive TB test and lack of symptoms and imaging abnormalities; treatment is warranted (choice 1 is incorrect). RIPE therapy is the treatment of choice for active TB but is not required for latent TB (choice 3 is incorrect). Isoniazid and rifapentine weekly x 3 months is a preferred treatment regimen for latent TB (choice 2 is correct). Rifampin monotherapy is a treatment option but the duration is only 4 months, not 9 months.
Citation: Sterling TR, Njie G, Zenner D, et al. Guidelines for the Treatment of Latent Tuberculosis Infection: Recommendations from the National Tuberculosis Controllers Association and CDC, 2020. MMWR Recomm Rep. 2020;69(1):1-11.
A 52-year-old male presents with shortness of breath and chest pain after smoking crack cocaine. History includes end stage renal disease (hemodialysis 3 x weekly) and systolic heart failure. Physical exam showed jugular venous distention. Blood pressure is 210/110 mmHg and heart rate 78 BPM. What treatment is best?
A. Dobutamine
B. Furosemide
C. Nitroglycerin
D. Normal Saline
Answer: C. Nitroglycerin
Rationale: The answer is option C; nitroglycerin. Based on the physical exam and history, the patient is most likely suffering from flash pulmonary edema and hypertension. Nitroglycerin will help with both flash pulmonary edema (reduce preload) and lower blood pressure. Furosemide most likely would not be effective in this patient secondary to his underlying end stage renal disease. Dobutamine is not indicated in this patient because he is not showing signs of cardiogenic shock and is hypertensive. Normal saline is not indicated because he is showing signs of volume overload.
Citation: Yancy CW, et al. 2013 ACCF/AHA Guideline for the management of heart failure: executive summary: a report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines. Circulation 2013;62:1495-1539.
A 64-year-old man with a history of hypertension presents with chest pain and no jugular venous distention, shortness of breath or lower extremity swelling. He is admitted for medical management of NSTEMI complicated by new atrial fibrillation and reduced left ventricular ejection fraction (25%). Which rate-control agent should be started?
A. Digoxin
B. Metoprolol succinate
C. Metoprolol tartrate
D. Verapamil
B. Metoprolol succinate
Rationale: Option B is the correct answer. Patients with acute coronary syndrome, such as NSTEMI, should be initiated on a beta-blocker in the absence of hemodynamic instability, low cardiac output, or other contraindications. For patients with reduced left ventricular ejection fraction, the beta-blocker chosen should be one of the 3 drugs proven to reduce mortality (carvedilol, metoprolol succinate, or bisoprolol). Metoprolol tartrate (option 3) has not been shown to reduce mortality in patients with reduced systolic function. A non-dihydropyridine calcium channel blocker (option 4) would not be recommended given this patient’s LV dysfunction. Digoxin (option 1) could be considered as additional therapy for this patient if unable to achieve rate control but would not be considered first-line.
Citations: 1) Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC Guideline for the Management of Patients with Non-ST-Elevation Acute Coronary Syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014 Dec 23;130(25):e344-e426. 2) 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol 2022; 79(17):e263–e421