Mannheim's peritonitis index in the prediction of postoperative outcome of peritonitis.

Objective: evaluate the effectiveness of MPI to predict mortality in patients with peritonitis in Santa Casa de Misericordia de Vitoria Hospital (HSCMV).

Methods: a longitudinal observational cohort retrospectively study, with a sample of 75 patients diagnosed with peritonitis between January 2010 to December 2 of 2015, in HSCMV and with all the necessary criteria for the calculation of IPM.

Results: we found a profile of the patients, 33 female and 42 male, mean age 42 years, 11 deaths and 14.67% mortality percentage. Comparing the MPI variables into two groups (survivors and deceased) was found that older than 50 years, presence of malignancy and patients with organ dysfunction have statistical significance for mortality, with p<0.05. The MPI ranged between 4-41 points, with average of 21.2 points. However, among the dead, the score ranged from 23 to 41, with a mean of 32.8. Therefore, the cutoff point of 27 points was established by evaluating the best value of Kappa concordance index, and through it were calculated: 90.90% sensitivity and specificity of 78.13% by the ROC curve.

Conclusion: based on these results, it was established that the MPI was effective in estimating the risk of death when the index reaches values = 27 points. Categorizing patients into different risk groups helps in determining a better prognosis and defining operative risk, thus contributing to the choice of the surgical procedure nature.