A 58-year-old man with a history of alcohol-associated cirrhosis and refractory ascites is… — USMLE Step 2 CK

A 58-year-old man with a history of alcohol-associated cirrhosis and refractory ascites is hospitalized due to an acute rise in serum creatinine. Over the past week, his weight has increased by $4$ kg ( $8.8$ lbs), and his urine output has decreased. His home medications include furosemide, spironolactone, and nadolol. On admission, his temperature is $37.1^\circ$ C ( $98.8^\circ$ F), blood pressure is $90/60$ mm Hg, and pulse is $98$ /min. Physical examination reveals scleral icterus, spider angiomas, and a markedly distended abdomen with shifting dullness. There is no abdominal tenderness, rebound, or guarding. Lungs are clear to auscultation. Laboratory studies on admission reveal:

Sodium: $131$ mEq/L
Potassium: $4.2$ mEq/L
Bicarbonate: $22$ mEq/L
BUN: $45$ mg/dL
Creatinine: $2.8$ mg/dL (baseline $1.1$ mg/dL one month ago)
Total bilirubin: $3.5$ mg/dL

Diagnostic paracentesis yields clear, yellow fluid with a leukocyte count of $120$ /mm $^3$ ( $10\%$ neutrophils) and negative Gram stain. All diuretics and nadolol are discontinued. He is given intravenous albumin at a dose of $1$ g/kg/day. Forty-eight hours later, his blood pressure is $92/60$ mm Hg and pulse is $95$ /min. Repeat laboratory studies show a serum creatinine of $3.1$ mg/dL. Urinalysis reveals no red blood cells, white blood cells, or casts. Urine sodium concentration is $8$ mEq/L. Renal ultrasound shows normal kidney size with no hydronephrosis. Which of the following is the most appropriate next step in management?

Initiate combination therapy with midodrine and octreotideAnswer
B
Administer intravenous piperacillin-tazobactam
C
Perform an echocardiogram to evaluate for heart failure
D
Administer intravenous sodium bicarbonate infusion
E
Obtain a computed tomography scan of the abdomen to evaluate for small bowel obstruction

Answer

The most appropriate next step is to initiate combination therapy with midodrine and octreotide, along with continued intravenous albumin.

This patient meets all the classic diagnostic criteria for hepatorenal syndrome (HRS), specifically HRS-AKI (formerly Type 1 HRS). HRS is a functional renal failure seen in advanced cirrhosis. It is caused by severe splanchnic arterial vasodilation, which critically reduces the effective arterial blood volume. This triggers intense activation of the renin-angiotensin-aldosterone system and the sympathetic nervous system, resulting in profound reflex renal vasoconstriction. The diagnosis requires the presence of cirrhosis with ascites, acute kidney injury, the absence of other causes of AKI (such as shock or nephrotoxic drugs), the lack of intrinsic renal disease (evidenced by a bland urinalysis and normal ultrasound), and the failure of renal function to improve after at least 48 hours of diuretic withdrawal and volume expansion with intravenous albumin. Because the core pathophysiology is splanchnic vasodilation, the treatment of choice relies on splanchnic vasoconstrictors. In the United States, a combination of midodrine (an alpha-1 adrenergic agonist) and octreotide (a somatostatin analog), along with continued albumin infusions, is the standard medical therapy. Terlipressin and norepinephrine are also utilized as first-line therapies depending on availability and care setting.

Step-by-Step Solution

Analyze the patient's clinical presentation and initial laboratory findings.

The patient has advanced cirrhosis with refractory ascites and a new-onset acute kidney injury (serum creatinine increased from

1.1

2.8

mg/dL).

Establishing the presence of severe AKI in the setting of portal hypertension is the first step in the diagnostic algorithm for renal failure in cirrhosis.

Evaluate the response to diuretic withdrawal and targeted volume expansion.

Despite stopping all diuretics and administering intravenous albumin (

1

g/kg/day) for

48

hours, the serum creatinine worsened to

3.1

mg/dL.

This lack of response strictly rules out simple volume depletion (pre-renal azotemia) and fulfills a core diagnostic criterion for hepatorenal syndrome.

Rule out other intrinsic and post-renal causes of acute kidney injury.

The urinalysis is completely bland, urine sodium is profoundly low (

8

mEq/L), ultrasound shows no obstruction, and there is no shock or nephrotoxic drug use.

This definitively rules out intrinsic renal parenchymal disease (such as acute tubular necrosis) and post-renal obstruction.

Determine the appropriate treatment for the established diagnosis.

The diagnosis is hepatorenal syndrome (HRS-AKI). The definitive medical treatment requires splanchnic vasoconstrictors (midodrine and octreotide, or terlipressin) in addition to albumin.

HRS is driven by profound splanchnic vasodilation; using specific vasoconstrictors reverses this pathophysiology, increases effective arterial blood volume, and restores renal perfusion.

Key Concept

Diagnosis and management of Hepatorenal Syndrome (HRS-AKI)

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