COMSAE Renal and Urological Systems 1

Question 1

A patient presents with oliguria, hematuria, and periorbital edema 2-3 weeks after a streptococcal throat infection. Urinalysis shows RBC casts. What is the most likely diagnosis?

Accepted Answer

Post-streptococcal glomerulonephritis

Answer

Post-streptococcal glomerulonephritis presents with nephritic syndrome (hematuria, RBC casts, hypertension) occurring 2-3 weeks after Group A strep pharyngitis.

Question 2

On COMSAE, which diuretic is most appropriate for a patient with heart failure and severe symptomatic edema requiring rapid fluid removal?

Accepted Answer

Furosemide (loop diuretic)

Answer

Loop diuretics like furosemide act at the thick ascending limb of the loop of Henle, producing the most potent diuresis and are first-line for acute fluid overload.

Question 3

A 65-year-old man with diabetes presents with creatinine 3.2 mg/dL, hyperkalemia, and metabolic acidosis with a normal anion gap. Which acid-base disorder is most likely?

Accepted Answer

Type 4 renal tubular acidosis (hyperkalemic RTA)

Answer

Type 4 RTA is the most common RTA in adults, caused by hypoaldosteronism (often from diabetic nephropathy) leading to hyperkalemia and normal anion gap acidosis.

Question 4

Which finding best distinguishes prerenal azotemia from acute tubular necrosis (ATN)?

Accepted Answer

Fractional excretion of sodium (FENa) < 1%

Answer

In prerenal azotemia, intact tubular function avidly reabsorbs sodium, yielding FENa < 1%, whereas ATN causes tubular dysfunction resulting in FENa > 2%.

Question 5

A 30-year-old man presents with recurrent hematuria coinciding with upper respiratory infections (synpharyngitic hematuria). Kidney biopsy shows mesangial IgA deposits. What is the diagnosis?

Accepted Answer

IgA nephropathy (Berger disease)

Answer

IgA nephropathy (Berger disease) is characterized by mesangial IgA immune complex deposition, presenting with gross hematuria during mucosal infections (within 1-2 days).

COMSAE - Comprehensive Osteopathic Medical Self-Assessment Examination Practice Test

COMSAE - Comprehensive Osteopathic Medical Self-Assessment Examination Practice Test

COMSAE Renal and Urological Systems 1