Mannheim’s peritonitis index in the prediction of postoperative outcome of peritonitis

ABSTRACT 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.

摘要
目的：评估蒙得维的亚慈悲圣家医院（Hospital Santa Casa de Misericordia de Vitoria，HSCMV）内，腹膜炎患者的MPI对死亡风险的预测效能。
方法：本研究为回顾性纵向观察队列研究，纳入2010年1月至2015年12月2日期间于HSCMV确诊为腹膜炎、且满足MPI计算所需全部标准的75例患者作为研究样本。
结果：本研究纳入患者的基线特征为：女性33例，男性42例，平均年龄42岁；共发生死亡11例，总病死率为14.67%。将研究对象按生存状态分为存活组与死亡组，对比两组的MPI相关指标后发现，年龄＞50岁、合并恶性肿瘤以及存在器官功能障碍的患者，其死亡风险具有统计学显著性差异（p<0.05）。本研究中MPI评分区间为4~41分，平均分为21.2分；其中死亡组患者的MPI评分区间为23~41分，平均分为32.8分。通过评估Kappa一致性指数的最优阈值，确定MPI的最佳截断值为27分，以此为界经ROC曲线计算可得，该截断值下的灵敏度为90.90%，特异度为78.13%。
结论：基于上述研究结果，当MPI评分≥27分时，该指数可有效预测腹膜炎患者的死亡风险。将患者划分为不同风险等级，有助于优化预后判断与手术风险分层，进而为手术方式的选择提供依据。