MORTALITY OF NOSOCOMIAL PNEUMONIA IN VENTILATED PATIENTS - INFLUENCE OF DIAGNOSTIC-TOOLS

The overmortality induced by nosocomial infections, especially pneumon ia in ventilated patients (VNP), is still a matter of controversy beca use it is difficult to know precisely the respective effects of VNP pe r se and both the underlying illness and the severity of the disease t hat indicates ICU stay. During a 3-yr period, for each patient mechani cally ventilated for more than 48 h we recorded underlying illness, re ason for mechanical ventilation, clinical and therapeutic data collect ed during the first 48 h of ventilation, and death in the ICU. Patient s with suspicion of VNP (S-VNP) according to clinical, radiologic, and biologic criteria underwent bronchoscopy with protected specimen brus h (PSB) and bronchoalveolar ravage culture (BAL-C). VNP was confirmed (C-VNP) if PSB greater than or equal to 10(3) cfu/ml and/or BAL-C grea ter than or equal to 10(4) cfu/ml. Prognostic multivariate analysis wa s performed introducing S-VNP and C-VNP as time-dependent covariates. Of the 387 studied patients, 112 S-VNP and 56 C-VNP were observed with overall mortality of 43% (168 patients). MacCabe, APACHE II score, sh ock, use of sedatives and absence of enteral nutrition were additively associated with an increased mortality as well as C-VNP (relative ris k [88]: 1.8, p = 0.007). Nevertheless, when S-VNP and C-VNP were simul taneously introduced in the Cox model, only S-VNP remained associated with increased mortality. In patients suspected of VNP, confirmation o f VNP using PSB and/or BAL-C adds no prognostic information. Whether t his could be explained by the lack of sensitivity of protected distal samples or the severity of underlying conditions of S-VNP patients is still an open issue. A multivariate analysis based on follow-up data d uring the ICU course of ventilated patients will be initiated in the n ear future.