Effect of ventilator-associated pneumonia on mortality and morbidity

The aim of this study was to evaluate the attributable mortality and excess intensive care unit (ICU) stay as linked to ventilator-associated pneumonia (VAP) in a medical-surgical ICU. We performed a matched cohort study. The diagnosis of VAP was established when clinical, biologic, and radiologic signs of VAP were associated with the presence of at least one microorganism at a concentration greater than or equal to 10(3) CFU/ml on the protected specimen brush sample. Each case patient with VAP was matched to one control patient on the basis of the following potential confounding factors: same diagnosis and same indication for mechanical ventilation, same age +/- 5 yr, same sex, same APACHE II score +/- 5 on admission. In addition, control patients had to be ventilated for at least as long as the case patient prior to the onset of VAP, and date of admission of the case and control patients had to be matched within 1 yr. In 85 of the 97 patients with VAP, we were able to match one case patient with one control patient. Mortality was similar in both case (40%) and control (38.8%) patients. The duration of mechanical ventilation was increased in survivor case patients (27.2 +/- 24.7 d) compared with survivor control patients (18.5 +/- 15.7 d) (p < 0.01). The duration of hospitalization in ICU was increased in survivor case patients (34.9 +/- 23.6 d) compared with survivor control patients (26.1 +/- 18.6 d) (p < 0.02). When confounding factors were controlled, VAP did not appear to increase mortality.