From the Guidelines
Spontaneous bacterial peritonitis (SBP) should be suspected in any patient with acute liver failure who develops leukocytosis, especially when accompanied by fever, abdominal pain, worsening encephalopathy, or deteriorating renal function, as indicated by a WBC count of 18 in this scenario.
Key Considerations
- Diagnostic paracentesis should be performed immediately when SBP is suspected, regardless of the presence of ascites, as recommended by the American Association for the Study of Liver Diseases in their 2021 practice guidance 1.
- A positive diagnosis is confirmed when the ascitic fluid polymorphonuclear leukocyte count exceeds 250 cells/mm³.
- Empiric antibiotic therapy should be initiated promptly, typically with a third-generation cephalosporin like ceftriaxone (1-2g IV daily) or cefotaxime (2g IV every 8 hours) for 5-7 days, as suggested by various guidelines including those from the Journal of Hepatology in 2018 1 and Gut in 2021 1.
- For patients with renal dysfunction or severe liver disease, dose adjustments may be necessary, and albumin administration (1.5 g/kg on day 1 and 1 g/kg on day 3) is recommended alongside antibiotics to reduce the risk of renal impairment and improve survival, as supported by evidence from studies such as those referenced in 1.
Rationale
The rationale behind these recommendations is based on the high morbidity and mortality associated with SBP in patients with liver failure, and the importance of early diagnosis and treatment to improve outcomes. The use of third-generation cephalosporins as empiric therapy is supported by their effectiveness against common causative organisms and their penetration into ascitic fluid. Albumin administration is recommended to reduce the risk of renal impairment, a common complication in these patients.
Clinical Application
In clinical practice, it is crucial to maintain a high index of suspicion for SBP in patients with acute liver failure and leukocytosis, and to promptly initiate diagnostic paracentesis and empiric antibiotic therapy when SBP is suspected. Regular monitoring of the patient's condition and adjustment of the treatment plan as necessary are also essential to optimize outcomes.
From the Research
Suspecting Spontaneous Bacterial Peritonitis (SBP) in Acute Liver Failure
- SBP should be suspected in patients with acute liver failure and ascites, particularly those with a high white blood cell (WBC) count, such as 18 2, 3, 4.
- A high index of suspicion and a low threshold for performing an abdominal paracentesis are required to detect infection early, when survival is most likely 3.
- The diagnosis of SBP is based on ascitic fluid analysis, specifically polymorphonuclear cell count and culture (in blood culture bottles) 3, 4.
Risk Factors and Clinical Presentation
- Patients with cirrhosis and ascites are at high risk for developing SBP, particularly those with low-protein ascites (ascitic fluid total protein < 1g/dL) 2, 5.
- Fever and abdominal pain are the most common presenting symptoms, but asymptomatic patients are being increasingly recognized 4.
- A high WBC count, such as 18, may indicate an increased risk of infection, including SBP 2, 3, 4.
Diagnostic Criteria
- An absolute polymorphonuclear leukocyte count greater than 500/mm3 in ascitic fluid is highly suggestive of SBP 3, 4.
- Ascitic fluid lactate and pH may offer additional diagnostic assistance when the PMN count is ambiguous 4.
- Paracentesis is indicated when SBP is suspected, and ascitic fluid analysis should be performed promptly to confirm the diagnosis 3, 4.