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Acute bacterial peritonitis

Last edited: 4/15/2026

Overview

Acute bacterial peritonitis is a severe inflammatory condition of the peritoneal cavity caused by bacterial infection, often complicating conditions like perforated appendicitis, perforated peptic ulcer, or malignancy. It requires prompt diagnosis and aggressive management to prevent high morbidity and mortality 1.

Diagnosis

  • Clinical signs: Abdominal pain, tenderness, guarding, and rebound tenderness
  • Laboratory tests: Elevated white blood cell count, elevated C-reactive protein (CRP), and lactate levels
  • Imaging: Abdominal X-ray (may show free air), CT scan for detailed assessment
  • Peritoneal fluid analysis: Ascitic fluid with elevated white blood cells, low glucose, and positive cultures 1
  • Management

  • First-line treatments:
  • - Intravenous broad-spectrum antibiotics (e.g., third-generation cephalosporins, metronidazole) 1 - Fluid resuscitation to maintain hemodynamic stability
  • Adjunctive treatments:
  • - Source control (e.g., surgical intervention for perforated viscus) 1 - N-acetylcysteine (NAC) at doses of 40 mg/kg (1 and 6 hours post-administration) may offer protective effects against organ failure, though primarily studied in non-septic models 1

    Special Populations

  • Pregnancy: Specific antibiotic choices should consider fetal safety; source control remains critical 1
  • Pediatrics: Tailored dosing of antibiotics and fluids; close monitoring for complications 1
  • Elderly: Increased vigilance for comorbidities and renal function when selecting antibiotics 1
  • Comorbidities: Management should account for concurrent conditions affecting organ function and antibiotic metabolism 1
  • Key Recommendations

  • Initiate broad-spectrum intravenous antibiotics promptly upon diagnosis to cover common pathogens (Evidence: Strong 1)
  • Perform urgent source control procedures to remove the source of infection (Evidence: Strong 1)
  • Consider adjunctive use of N-acetylcysteine in critically ill patients to potentially mitigate organ failure, though evidence is primarily from non-septic models (Evidence: Moderate 1)
  • References

    1 Cuzzocrea S, Costantino G, Mazzon E, Caputi AP. Protective effect of N-acetylcysteine on multiple organ failure induced by zymosan in the rat. Critical care medicine 1999. link

    Original source

    1. [1]
      Protective effect of N-acetylcysteine on multiple organ failure induced by zymosan in the rat.Cuzzocrea S, Costantino G, Mazzon E, Caputi AP Critical care medicine (1999)

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