Nosocomial infection, indices of intrinsic infection risk, and in-hospitalmortality in general surgery

The objectives of this paper are to assess whether two indices of intrinsic infection risk (the SENIC and the NNIS index) predict in-hospital mortalit y and the attributable in-hospital mortality due to nosocomial infection in surgical patients. A prospective study on 4714 patients admitted to three hospitals has been carried out. The relative risk and its 95% confidence in terval (CI) were estimated. Multiple-risk factors adjusted for odds ratios (OR) were yielded by logistic regression analysis. Overall, 119 patients (2 .5%) died before hospital discharge. Both the SENIC and the NNIS indices we re related to in-hospital mortality in crude data. After controlling for se veral variables (age, sex, ASA score, cancer, renal failure, diabetes melli tus, stay at the ICU), the SENIC index did not show any significant trend w ith mortality (P=0.252), whereas the trend was significant for the NNIS ind ex (P<0.001). Risk of death in patients with one nosocomial infection was 7 .5%, and in patients developing more than one nosocomial infection was 17.1 %. After adjusting for several confounding variables, the development of an organ/space surgical site infection was significantly related to mortality (OR = 4.5, 95% CI 1.5-15.6) as was blood infection (OR = 17.3, 95% CI 3.5- 87.0). The association of a surgical site infection and either a respirator y tract infection or a blood infection also increased significantly the ris k of in-hospital mortality (OR = 3.3, 95% CI 1.2-8.7). In conclusion, the N NIS index is a good predictor of in-hospital mortality. Patients developing an organ/space surgical site infection and/or a blood infection have an in creased risk of in-hospital mortality.