What is the management and treatment approach for a patient with a history of liver disease, such as cirrhosis, suspected of having Spontaneous Bacterial Peritonitis (SBP)?

Management of Spontaneous Bacterial Peritonitis in Cirrhotic Patients

Perform immediate diagnostic paracentesis without delay in any cirrhotic patient with ascites at hospital admission or when clinical suspicion arises, then start empirical cefotaxime 2g IV every 8 hours plus intravenous albumin (1.5 g/kg within 6 hours, then 1 g/kg on day 3) as soon as the ascitic fluid polymorphonuclear count exceeds 250/mm³, without waiting for culture results. 1, 2, 3

Diagnostic Approach

When to Perform Paracentesis

Perform diagnostic paracentesis immediately in the following scenarios:

• All cirrhotic patients with ascites at hospital admission, even without symptoms (16% of SBP cases are completely asymptomatic) 1, 2
• Fever or signs of systemic inflammation (hypothermia, chills, tachycardia, tachypnea) 4
• Abdominal pain, tenderness, vomiting, or diarrhea 4
• Altered mental status or hepatic encephalopathy 4, 2
• Gastrointestinal bleeding 4, 2
• Shock or hemodynamic instability 4, 2
• Worsening liver and/or renal function 4, 2

Paracentesis Technique and Safety

Coagulopathy is NOT a contraindication to paracentesis. 5 Although cirrhotic patients typically have prolonged prothrombin time, paracentesis should proceed without routine correction. 5 Consider platelet transfusion only if platelets are <40,000-50,000/μL. 5 Use ultrasound guidance to optimize the procedure. 6

Diagnostic Criteria

SBP is diagnosed when ascitic fluid polymorphonuclear (PMN) count exceeds 250/mm³, regardless of culture results. 4, 1, 2 This lower threshold is deliberately chosen because the greater clinical risk lies with underdiagnosing SBP rather than overdiagnosing it—each hour of delay in treatment increases in-hospital mortality by 3.3%. 1

Obtain cultures properly:

• Inoculate at least 10 mL of ascitic fluid into blood culture bottles at bedside before starting antibiotics (increases culture sensitivity to >90%) 1, 2
• Simultaneously obtain blood cultures before antibiotic initiation 4, 1, 2
• Culture positivity is not required for diagnosis or treatment initiation 4, 1

Special Diagnostic Scenarios

Culture-negative neutrocytic ascites (PMN >250/mm³ with negative culture) should be treated identically to culture-positive SBP, as both have similar morbidity and mortality. 1

Bacterascites (positive culture but PMN <250/mm³): If symptomatic with signs of systemic inflammation, treat as SBP immediately. 4 If asymptomatic, repeat paracentesis—if culture remains positive regardless of neutrophil count, initiate treatment. 4

Secondary bacterial peritonitis should be suspected when patients have localized abdominal symptoms, multiple organisms on culture, very high ascitic neutrophil count, high ascitic protein concentration, or inadequate response to therapy. 4 These patients require prompt CT scanning and early surgical consultation. 4

Treatment Protocol

First-Line Antibiotic Therapy

Initiate empirical antibiotics immediately upon diagnosis without waiting for culture results. 1, 2, 3

Community-acquired SBP:

• Cefotaxime 2g IV every 8-12 hours for 5 days (77-98% resolution rates) 1, 2, 3, 5
• Alternative: Cefotaxime 2g IV every 6-8 hours for 5 days 1, 3
• Oral option for uncomplicated cases: Ofloxacin 400mg twice daily 1
• A 5-day course is as effective as 10 days 1, 3

Nosocomial or healthcare-associated SBP:

• Use carbapenem or piperacillin-tazobactam empirically 5, 6, 7
• Do NOT use quinolones in patients already on quinolone prophylaxis, in areas with high quinolone resistance, or in nosocomial SBP 1, 7

For patients on quinolone prophylaxis who develop SBP:

• Use cefotaxime or amoxicillin-clavulanic acid 1

Albumin Therapy: Critical for Mortality Reduction

Administer intravenous albumin 1.5 g/kg body weight within 6 hours of diagnosis, followed by 1.0 g/kg on day 3. 1, 2, 3 This regimen reduces mortality from 29% to 10% and decreases type 1 hepatorenal syndrome from 30% to 10%. 1, 2 Albumin therapy is essential and significantly improves survival when combined with appropriate antibiotics. 1, 2, 3

Monitoring Treatment Response

Perform repeat paracentesis at 48 hours to assess treatment efficacy. 1, 2, 3

Treatment success is defined as:

• PMN count decrease to <25% of pre-treatment value 1, 2, 3
• Clinical improvement in signs and symptoms 1, 3

Treatment failure is defined as:

• Failure of ascitic neutrophil count to decrease by at least 25% of pre-treatment value 1, 3
• Worsening of clinical signs and symptoms 1, 3

Management of Treatment Failure

If treatment fails at 48 hours, consider:

• Resistant bacteria requiring antibiotic modification based on culture sensitivities 1, 3
• Empiric escalation to broader-spectrum agents (carbapenem or piperacillin-tazobactam) 6, 7
• Secondary bacterial peritonitis requiring CT imaging and surgical consultation 4, 1, 3

Critical Pitfalls to Avoid

Do not delay paracentesis due to coagulopathy concerns. Most cirrhotic patients have prolonged PT/INR, but this is not a contraindication. 5 Delaying antibiotic therapy increases mortality by 10% for every hour's delay in cirrhotic patients with septic shock. 1

Do not wait for culture results to initiate treatment. The PMN count alone is sufficient to diagnose and treat SBP. 4, 1

Do not use quinolones in patients already on quinolone prophylaxis. This population requires cefotaxime or amoxicillin-clavulanic acid. 1

Do not omit albumin therapy. This is not optional—albumin significantly reduces mortality and hepatorenal syndrome. 1, 2, 3

Prognosis

SBP carries approximately 20% hospital mortality despite infection resolution. 1, 2, 3 Early appropriate antibiotic treatment combined with albumin therapy significantly improves survival. 1, 2, 3 The most common organisms are Escherichia coli, Klebsiella species, and Streptococcus species, though Gram-positive cocci and multidrug-resistant bacteria are increasingly common. 6, 8, 7