Renal and Urological Systems Flashcards

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?

Answer: Post-streptococcal glomerulonephritis

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

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

Answer: Furosemide (loop diuretic)

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.

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?

Answer: Type 4 renal tubular acidosis (hyperkalemic RTA)

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.

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

Answer: Fractional excretion of sodium (FENa) < 1%

In prerenal azotemia, intact tubular function avidly reabsorbs sodium, yielding FENa 2%.

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?

Answer: IgA nephropathy (Berger disease)

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

Which electrolyte abnormality is the most immediately life-threatening complication of acute renal failure requiring emergent treatment?

Answer: Hyperkalemia

Hyperkalemia is the most immediately dangerous complication of acute renal failure because it can cause fatal cardiac arrhythmias including ventricular fibrillation.