LENGTH OF STAY AND MORTALITY IN CRITICALLY ILL PATIENTS WITH VENTILATOR-ASSOCIATED PNEUMONIA

 

Rocco, J.R.; Guimarães, M.M.R.; Nouér, S.A.

jrrocco@openlink.com.br

 

Infection Control and Intensive Care Unit - Hospital Universitário Clementino Fraga Filho - Federal University of Rio de Janeiro – Rio de Janeiro - Brazil

 

Introduction: Ventilator-associated pneumonia (VAP) frequently complicates the outcome of patients in the intensive care unit (ICU). The question of whether or not critically ill patients are at increased risk of death as a result of acquiring pneumonia remains controversial. Objective: To determine length of stay and the attributable mortality associated with VAP. Methods: Prospective cohort of mechanically ventilated (MV) patients admitted in ICU between Sep 1999 and Aug 2000. The diagnosis of VAP was done according to NNISS definitions. A two tailed chi-square (with Yates correction) was used to compare differences between groups, with VAP and the remained group of patients (C), for discrete variables and Mann Whitney Rank Sum for the nonparametric continuous variables. Linear regression and Pearson correlation coefficient were used to evaluate the relationship between number of days of MV and VAP (p<0.05). Results: A total of  193 critically ill patients were studied; 83 (43%) developed VAP, 5.6 ±  4.8 days of MV. The mean age was 59 ± 20 years. The risk of developing VAP increased with the number of days of MV (R=0.992); the hazard rate was 8.8% between 1-3 days of MV and 83.3% above 15 days, with an overall rate of 42.2 cases per 1000 ventilator-days. The majority of VAP patients had medical conditions (62.6% VAP vs. 41.8% C; p=0.006). VAP patients developed more ARDS (21.7% vs. 6.4%; p=0.004), atelectasis (20.5% vs. 4.5%; p=0.002), pneumothorax (13.3% vs. 2.7%; p=0.02) and sinusitis (13.3% vs. 0.9%; p=0.0002). Duration of mechanical ventilation was longer in VAP patients (16.7 ± 16.5 vs. 5.4 ±  4.8 days; p<0.0001). Time to start the weaning process was also longer (11.5 ± 8.7 vs. 4.0 ± 3.5 days; p<0.0001). In addition, VAP group stayed more days in ICU (17.7 ± 18.3 vs. 6.1 ± 5.1 days; p<0.0001) and in the hospital (32.3 ± 25.7 vs. 22.4 ± 22.4 days; p=0.002). The mortality rate of VAP patients was not different (47% vs. 44.5%; p=0.84) as well as APACHE II probability of death score (43.6 ± 26.6% vs. 41.4 ± 29.0%; p=0.39). Conclusions: VAP prolonged the time in mechanical ventilation, ICU and hospital length of stay and number of complications, but did not increase mortality in our critically ill patients.