What is the treatment for a significant ascitic fluid cell count indicative of spontaneous bacterial peritonitis (SBP)?

Treatment of Spontaneous Bacterial Peritonitis (SBP)

Immediately initiate empirical antibiotic therapy with a third-generation cephalosporin (cefotaxime 2g IV every 8-12 hours or ceftriaxone 1-2g IV every 12-24 hours) plus intravenous albumin (1.5 g/kg at diagnosis and 1 g/kg on day 3) as soon as the ascitic fluid polymorphonuclear (PMN) count exceeds 250 cells/mm³, without waiting for culture results. 1, 2, 3

Diagnostic Confirmation

• SBP is diagnosed when ascitic fluid PMN count >250/mm³, regardless of culture results 1
• Obtain ascitic fluid culture by inoculating at least 10 mL into blood culture bottles at bedside before starting antibiotics, which increases culture sensitivity to >90% 1
• Simultaneously obtain blood cultures before antibiotic initiation to increase organism isolation rates 1
• Do not delay treatment waiting for culture results—the PMN count is sufficient to initiate therapy 1

First-Line Antibiotic Therapy

Community-Acquired or Standard SBP

Third-generation cephalosporins remain the gold standard for initial empirical treatment:

• Cefotaxime 2g IV every 8-12 hours for 5 days is the most extensively studied regimen with 77-98% resolution rates 1, 2
• Ceftriaxone 1-2g IV every 12-24 hours is an equally effective alternative 4
• A 5-day course is as effective as 10 days of treatment 1

Alternative Regimens for Uncomplicated Cases

• Oral ofloxacin 400mg twice daily can be used in uncomplicated SBP (patients without vomiting, shock, grade II or higher hepatic encephalopathy, or serum creatinine >3 mg/dL) 1
• Amoxicillin-clavulanic acid (1g/0.2g IV every 8 hours, then 0.5g/0.125g PO every 8 hours) shows similar efficacy to cefotaxime 1
• Ciprofloxacin (200mg IV every 12 hours for 2 days, then 500mg PO every 12 hours for 5 days) is effective but more costly 1

Nosocomial or Healthcare-Associated SBP

For nosocomial SBP or patients with recent hospitalization, use broader-spectrum coverage due to high rates of multidrug-resistant organisms (MDROs):

• Meropenem 1g IV every 8 hours plus daptomycin 6 mg/kg/day is significantly more effective than ceftazidime for nosocomial SBP (86.7% vs 25% resolution rate) 5
• Consider carbapenems in critically ill patients or those in intensive care units 1
• Avoid quinolones in patients already on quinolone prophylaxis, in areas with high quinolone resistance, or in nosocomial settings 1, 2

Albumin Therapy: Critical for Reducing Mortality

Intravenous albumin administration is essential and significantly reduces mortality and hepatorenal syndrome:

• Give 1.5 g/kg body weight within 6 hours of diagnosis, followed by 1.0 g/kg on day 3 1, 3
• This regimen reduces mortality from 29% to 10% and decreases type 1 hepatorenal syndrome from 30% to 10% 1
• Albumin is particularly critical in patients with baseline serum bilirubin ≥4 mg/dL or serum creatinine ≥1 mg/dL 1
• The benefit in patients with bilirubin <4 mg/dL and creatinine <1 mg/dL is less clear but still recommended 1

Monitoring Treatment Response

Perform a repeat paracentesis at 48 hours to assess treatment efficacy:

• Treatment success is defined as a decrease in ascitic PMN count to <25% of the pre-treatment value 1, 2
• Clinical improvement should accompany the laboratory response 1
• If PMN count fails to decrease by at least 25%, suspect treatment failure 1

Management of Treatment Failure

If treatment fails (no PMN reduction or clinical worsening), consider:

• Resistant bacteria requiring antibiotic modification based on culture sensitivities or empiric escalation to broader-spectrum agents 1, 2
• Secondary bacterial peritonitis requiring CT imaging and surgical consultation 1
• Change antibiotics according to in vitro susceptibility or switch to alternative broad-spectrum agents empirically 1

Common Pitfalls and Caveats

• Never delay antibiotic initiation—every hour of delay in septic shock increases mortality by 10% 2
• Avoid aminoglycosides as empirical therapy due to nephrotoxicity risk 1
• Patients with focal intra-abdominal pathology (diverticulitis, cholecystitis) may have PMN >250/mm³ but require treatment for the specific condition, not SBP 1
• Do not place chest tubes for spontaneous bacterial empyema despite the term "empyema"—treat with antibiotics as for SBP 1
• Cefotaxime and amoxicillin-clavulanic acid remain effective in patients who develop SBP while on norfloxacin prophylaxis 1, 2

Prognosis

• SBP carries approximately 20% hospital mortality despite infection resolution 1, 3
• Early appropriate antibiotic treatment combined with albumin therapy significantly improves survival 3
• Ineffective response to first-line treatment is a strong independent predictor of 90-day mortality 5