Aims: Secondary peritonitis is a common surgical emergency worldwide, but there is limited information on whether pre-operative serum High Mobility Group Box Protein 1 (HMGB1) can help in identification of patients at risk for mortality.

Methodology: The in-patient record of 140 patients of secondary peritonitis was prospectively maintained to identify the role of pre-operative serum HMGB1 in predicting mortality.

Results: There were 123 (87.86%) male and 17 (12.14%) female patients with an average age of 38.81 years; the commonest site of perforation was gastroduodenal area (64 patients; 45.71%). Mortality in the present series was 15% (21 patients). Univariate analysis revealed higher mortality in patients above 50 years of age, those with pre-existing comorbidity, and in those patients having on admission APACHE II score greater than 6, respiratory rate greater than 23 per minute, need for vasopressor support, deranged pre-operative serum creatinine (greater than 1.4 mg/dl), and bicarbonate (less than 18 mmol/L); HMGB1 levels higher than 130 ng/ml was associated with significantly higher mortality.

Conclusion: HMGB1 levels (greater than 130 ng/ml) are associated with significantly higher mortality, especially in association with age above 50 years and the need for inotropic support on admission. Understanding the role of HMGB1 may open further avenues for therapy in secondary peritonitis.