A 68-year-old man is evaluated on hospital day 3 for acute decompensated heart failure. On… — USMLE Step 3

A $68$ -year-old man is evaluated on hospital day $3$ for acute decompensated heart failure. On admission, he had severe dyspnea, orthopnea, and $3+$ bilateral lower extremity edema. He was initiated on intravenous bumetanide. Over the past $48$ hours, his total urine output has been $6,500\text{ mL}$ , and his weight has decreased from $92\text{ kg}$ to $86\text{ kg}$ . Today, the patient reports significant improvement in his breathing and is able to lie flat comfortably. Physical examination shows clear lungs bilaterally and trace lower extremity edema. Vital signs are temperature $37.0^\circ\text{C}$ ( $98.6^\circ\text{F}$ ), blood pressure $112/70\text{ mmHg}$ , and heart rate $82/\text{min}$ .

Laboratory studies today:
Blood urea nitrogen: $54\text{ mg/dL}$ (baseline $24\text{ mg/dL}$ )
Serum creatinine: $2.3\text{ mg/dL}$ (baseline $1.2\text{ mg/dL}$ )

Which of the following is the most appropriate next step in management?

A
Administer an intravenous bolus of $0.9\%$ sodium chloride
B
Continue intravenous bumetanide at the current dose
Hold intravenous bumetanide and monitor renal functionCevap
D
Add oral metolazone
E
Obtain a renal ultrasound

Cevap

The correct answer is to hold intravenous bumetanide and monitor renal function.

The patient has experienced significant diuresis, evidenced by a

6\text{ kg}

weight loss,

6,500\text{ mL}

urine output, and resolution of his heart failure symptoms. However, his new laboratory findings show an acute rise in blood urea nitrogen and serum creatinine, with a BUN-to-creatinine ratio greater than

20:1

. This pattern clearly indicates prerenal acute kidney injury secondary to intravascular volume depletion from aggressive diuresis. Because the patient is clinically euvolemic (clear lungs, breathing comfortably flat), the most appropriate next step in treatment evaluation is to hold the loop diuretic. This approach prevents further volume depletion and allows renal perfusion to recover, while strictly observing the patient to ensure he does not slip back into volume overload.

Adım Adım Çözüm

Assess the patient's clinical volume status based on symptoms and physical exam.

The patient can lie flat comfortably, has clear lungs, and has trace edema, indicating successful resolution of volume overload.

Clinical assessment is the primary driver for determining if ongoing diuresis is necessary.

Evaluate the new laboratory findings in the context of recent therapy.

BUN has increased to

54\text{ mg/dL}

and creatinine to

2.3\text{ mg/dL}

(BUN:Cr ratio

> 20:1

To identify any adverse effects of aggressive diuresis, specifically prerenal acute kidney injury.

Determine the safest and most appropriate intervention to address the acute kidney injury.

Hold the intravenous loop diuretic and monitor the patient.

The patient is clinically euvolemic, and pausing the diuretic allows intravascular volume to equilibrate and renal perfusion to recover without risking recurrent heart failure.

Anahtar Kavram

In patients receiving aggressive diuresis for heart failure, the development of prerenal acute kidney injury (elevated BUN and creatinine) with clinical euvolemia indicates overdiuresis, and the appropriate management is to hold the diuretic rather than administer intravenous fluids.

Tahmini Süre:1m 15s

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