Clinical evaluation of the Mannheim Prognostic Index in post-operative peritonitis: a prospective cohort study.

Postoperative peritonitis (PoP), despite their relatively low incidence, are associated with high mortality. Such poor outcomes are also related to the high proportion of aged patients, whose intra-abdominal infections are difficult to manage. The study included 84 consecutive patients with PoP. The aim was the validation of the Mannheim Prognostic Index (MPI) in the context of PoP and the assessment of the prognostic impact of age and other clinical factors in a large series from a tertiary center. PoP had an incidence of 3.9% in all the abdominal surgeries in the study period. Surgical control of POP focus was achieved in 90.5% of cases and a complete abdominal clearance in 58.3%. Complication rate was 75% with a mortality of 26.2%. For MPI score, the ROC curve indicated a cut-off value of 29 with a sensitivity of 72.7% and specificity of 67.7% in predicting death. At univariate analysis, factors significantly related to poorer prognosis included advanced age (p 0.001), site of primary surgery (p 0.05), lack of abdominal clearance (p 0.003), generalized peritonitis (p 0.04) and high MPI score (p < 0.001). Age, MPI score and absence of abdominal clearance resulted in independent prognostic factors at multivariate analysis. MPI showed good efficacy in identifying POP patients at high risk of death. The increased risk of mortality related to advanced age should be considered with MPI score in planning the treatment. An aggressive and early diagnostic-therapeutic approach is required to reduce the MPI score and improve the prognosis.