Outcomes and prognostic factors of secondary and tertiary peritonitis in an ICU: a prospective analysis

Abstract

Background: Intra-abdominal infections (IAIs) causing secondary and tertiary peritonitis contribute significantly to sepsis and septic shock-related mortality in African ICUs. Yet the data from low-to-middle income countries (LMICs) remain sparse. This study evaluates prognostic factors and outcomes in a tertiary care ICU in South Africa.

Methods: A prospective observational study was conducted on 129 adult patients with secondary or tertiary peritonitis admitted to ICU at Dr George Mukhari Academic Hospital (DGMAH) between February 2022 and February 2023. Demographics, antimicrobial resistance, and surgical management strategies were assessed. Predictors of mortality and prolonged ICU stay were analysed using Cox regression.

Results: Median patient age was 52 years (IQR 37–65); 59.7% were male. Gastroduodenal perforations (34.1%) were most common. Multidrug-resistant (MDR) organisms were isolated in 23.3%. ICU mortality was 21.7%. APACHE II ≥ 25 (HR 3.1, 95% CI: 1.7–5.7; p < 0.001), ≥ 3 relooks (HR 2.99, 95% CI: 1.2–7.3; p = 0.014), and open abdomen (HR 3.2, 95% CI: 1.3–7.9; p = 0.008) were associated with mortality. Multiple organ dysfunction syndrome (MODS) was associated with prolonged ventilation (HR 1.41; p = 0.002).

Conclusion: Secondary and tertiary peritonitis in African ICUs is associated with sepsis and septic shock and high surgical burden. Early risk stratification, timely source control, and antibiotic stewardship are essential. This is among the few prospective analyses from an LMIC setting and provides actionable data for context-sensitive guidelines.