[Incidences of early- and late-onset ventilator-associated pneumonia in a postanesthesia and critical care unit]

To ascertain the frequency, risk factors, and causes of early- and late-onset ventilator-associated pneumonia (VAP) in a postanesthesia and critical care unit.

A prospective study was carried out between January 1, 1996 and December 31, 2001 of all ventilated patients staying longer than 48 hours in the critical care unit, with follow-up for 48 hours following discharge from the unit. Descriptive statistics were compiled for episodes of early- and late-onset VAP for a period of up to 4 days after intubation; univariate and multiple variable Cox regression analyses were also carried out.

A total of 3614 patients were admitted to the unit (study cohort, 652 patients). The mean length of stay in the unit for the study cohort was 13.64 days. The most frequent diagnosis was multiple trauma (50.46%). The incidence density of VAP was 20.31 cases per 1000 patient-days on mechanical ventilation. The pathogens most often isolated in early-onset VAP cases were Staphylococcus aureus and Pseudomonas aeruginosa. In late-onset cases, the pathogens were Pseudomonas species. Early-onset VAP was 2.54 and 2.81 times more frequent in comatose and head-injury patients, respectively. Those rates were significantly different in late-onset cases.

Early-onset VAP was more common in comatose and head-injury patients. The risk of developing late-onset versus early-onset VAP was twice as great for postoperative patients.