Ventilator-associated pneumonias in a cardiothoracic surgery centre postoperative intensive care unit

Cases of ventilator-associated pneumonia (VAP) were investigated in a cardiothoracic surgery postoperative intensive care unit between 1 January 1999 and 31 December 1999. A total of 1716 patients who had undergone cardiothoracic operations and admitted to the intensive care unit (ICU) were included in the study. Patient- and laboratory-based prospective surveillance of VAP was done along with other hospital-acquired infections. During the study period a total of 26 585 patient-days with 2708 ventilator-days were recorded. Forty-six cases of VAP occurred in 36 of 1716 patients who had undergone cardiothoracic operations (2.09%, 1.3 episodes of pneumonia per patient). The ventilator utilization rate at our institution was 0.10. There were 16.4 VAPs per 1000 ventilation days. Thirty-eight percent of VAP were caused by Gram-negative enteric rods, 34% by Pseudomonas aeruginosa, and 17% by Staphylococcus aureus. VAP was polymicrobial in 9% of cases. No causative micro-organism was identified in 2% of cases. The same bacteria were isolated in both blood and endotracheal aspirate cultures in 10 of 46 pneumonia cases (22%). The crude mortality rate of VAP was calculated as 30%