From the Guidelines
The initial workup for hepatorenal syndrome (HRS) should focus on excluding other causes of acute kidney injury in patients with advanced liver disease, beginning with a thorough history and physical examination, followed by comprehensive laboratory tests and imaging studies, as outlined in the most recent guidelines 1. The workup should include:
- Comprehensive laboratory tests, such as complete blood count, comprehensive metabolic panel, urinalysis, and urine electrolytes
- Specific tests, including serum creatinine, blood urea nitrogen, sodium, and assessment of urine sodium concentration and fractional excretion of sodium, which is typically low (<1%) in HRS
- Abdominal ultrasound with Doppler to evaluate kidney structure and rule out obstruction or vascular abnormalities
- Additional tests, such as urinary sediment examination, urine protein quantification, and plasma volume expansion with albumin (1 g/kg up to 100 g) to assess for response
- Diagnostic paracentesis may be necessary if ascites is present to rule out spontaneous bacterial peritonitis The workup aims to confirm HRS by meeting diagnostic criteria: cirrhosis with ascites, serum creatinine >1.5 mg/dL, no improvement after albumin challenge, absence of shock, no recent nephrotoxic drugs, and exclusion of parenchymal kidney disease. The most recent and highest quality study recommends that treatment of HRS-AKI should be initiated with albumin at a dose of 1 g/kg intravenously on day 1 followed by 20–40 g daily along with vasoactive agents, such as terlipressin, and continued either until 24 hours following the return of the serum creatinine level to within ≤0.3 mg/dL of baseline for 2 consecutive days or for a total of 14 days of therapy 1. Key considerations in the management of HRS include:
- Close monitoring for possible development of side effects of vasoconstrictors and albumin, including ischemic complications and pulmonary edema
- Response to terlipressin or norepinephrine is defined by creatinine decreases to <1.5 mg/dL or return to within 0.3 mg/dL of baseline over a maximum of 14 days
- Recurrence may occur after treatment discontinuation and should be retreated
- All patients with cirrhosis and AKI should be considered for urgent liver transplant evaluation given the high short-term mortality even in responders to vasoconstrictors.
From the Research
Initial Workup for Hepatorenal Syndrome (HRS)
The initial workup for HRS involves several key steps to diagnose and manage this life-threatening condition:
- Diagnosis of HRS relies on serum creatinine changes, rather than a fixed high value, as recommended by the International Club of Ascites 2
- Urinary biomarkers, such as urinary neutrophil gelatinase-associated lipocalin, can help identify patients with acute tubular necrosis and differentiate them from HRS 2
- Assessment of kidney function is crucial, and novel glomerular filtration rate equations have been developed to better estimate kidney function in patients with liver disease 3
- Differential diagnosis from other forms of acute kidney injury (AKI), particularly acute tubular necrosis, is essential 4
Diagnostic Criteria
The diagnosis of HRS is based on the following criteria:
- Reduction in renal blood flow and glomerular filtration rate 5
- Absence of evidence of intrinsic kidney disease, such as hematuria, proteinuria, or abnormal kidney ultrasonography 5
- Presence of cirrhosis and portal hypertension 6
Laboratory Tests
Laboratory tests that may be useful in the initial workup of HRS include:
- Serum creatinine and bilirubin levels 2
- Urinary biomarkers, such as urinary neutrophil gelatinase-associated lipocalin 2
- Blood pressure and systemic inflammatory response syndrome markers 2
Imaging Studies
Imaging studies, such as kidney ultrasonography, may be useful to rule out other causes of kidney injury and to assess kidney function 5
Treatment and Prevention
Treatment and prevention of HRS involve: