Predictive power of Mannheim Peritonitis Index.

Objective: To evaluate Mannheim Peritonitis Index (MPI) in predicting outcome in patients with secondary peritonitis and to assess each risk factor independently regarding its contribution towards final outcome.

Design: Prospective analytical study.

Place And Duration Of Study: Surgical Unit-II of Rawalpindi General Hospital, from December 1999 to January 2001.

Patients And Methods: One hundred and twenty-six patients who presented to the department with secondary peritonitis were included in the study. MPI score was calculated for each patient on a pre-designed proforma and the patients were followed-up till death or discharged from the hospital. Death was the main outcome measure against which the MPI scores were analyzed under two categories; (i) score > or = 26 and < 26 (ii) scores < 21, 2-29, and > 29. Data was analyzed on software SPSS (version 11.0). Chi-square test was used to assess any significant association between scores and outcome. Odds ratios were calculated for individual risk factors.

Results: Mortality rate for MPI score > or = 26 was 28.1% while for scores less than 26 it was 4.3%. For MPI scores pound 20 mortality rate was 1.9%, for scores 21-29 it was 21.9% and for score 30 or more it was 28.1%. Chi-square showed significant association between mortality and increasing MPI score (p < 0.01). Odd ratios calculated were significant for age > 50 years, malignancy, organ failure, pre-operative duration of peritonitis > 24 hours and cloudy, purulent exudate.

Conclusion: Increasing MPI score is strongly associated with outcome in secondary peritonitis.