Capillary Leak Index Versus Conventional Biomarkers in Predicting Sepsis-Related Outcomes

• Capillary Leak Index Versus (Diagnostic test): Blood samples will be collected at three time points: within 1-2 hours of ICU admission (Day 0), Day 1, Day 2 and Day 7, to monitor trends in CLI and conventional biomarkers during the ICU stay. • CR

Primary outcomes

• all-cause mortality [From 1-10-2025 to 1-10-2026]

Sex: All, ages: 18 Years to any

Inclusion Criteria:

Age ≥ 18 years.

Postoperative secondary peritonitis requiring ICU admission, with clinical evidence of:

Diffuse or localized abdominal pain/tenderness. Peritoneal signs (e.g., guarding, rigidity, rebound tenderness). Imaging or intraoperative confirmation of purulent/exudative intra-abdominal fluid.

Systemic inflammation (e.g., fever, leukocytosis, or vasopressor requirement). Sepsis diagnosis per Sepsis-3 criteria: Suspected/confirmed infection with acute increase in SOFA score ≥2 points (6).

Anticipated ICU stay ≥48 hours postoperatively.

Exclusion Criteria:

* Pregnancy

  * Advanced liver disease (Child-Pugh class B or C) that might independently affect albumin levels
  * Advanced kidney disease (CKD stage 4 or 5) or patients on chronic dialysis
  * Expected mortality within 48 hours of ICU admission
  * Patients with primary peritonitis or tertiary peritonitis
  * Immunocompromised patients (e.g., on chronic immunosuppressive therapy, solid organ transplant recipients, patients with HIV and CD4 count <200/mm³)
  * Patients with pre-existing systemic inflammatory diseases that might affect baseline CRP levels
  * Patients participating in interventional trials that might affect outcomes