STUDIES OF PREVALENCE OF VENTILATOR-ASSOCIATED PNEUMONIA IN INTENSIVE CARE UNIT OF THE UNIVERSITY BRAZ CUBAS ? MOGI DAS CRUZES HOSPITAL (BRAZIL) AND FACTORS AND CHARACTERIZE PATIENT EVOLUTION

Pneumonia is the second leading nosocomial infection and presents high mortality rates. Ventilator-associated pneumonia (VAP) is the leading infection in intensive care units (ICUs).The incidence ranges from 9% to 68%, depending on the diagnostic method used and on the population studied. Its lethality is high, ranging from 33% to 71%, and the case fatality rate can reach up to 55%. Of all cases of hospital-acquired pneumonia , 86% are associated with mechanical ventilation(MV). However, only 9% to 27% of mechanically ventilated patients develop pneumonia. The prevalence reported is 21.7 to 35.6 cases/1000 MV days, compared with 3.2 cases/1000 days for patients not on ventilation. The proportion of intubated patients who develop pneumonia varies from 10% to 50%, with an approximaterisk of 1% to 3% per day of endo tracheal intubation.
OBJECTIVE: To determine the prevalence of ventilator-associated pneumonia in an intensive care unit, as well as to identify related factors and characterize patient evolution. METHODS: This study evaluated 98 patients on mechanical ventilation for more than 24 hours in a university hospital. RESULTS: Ventilator-associated pneumonia developed in 43.2% of the patients, translating to 39.6 cases/1000 ventilator-days: 55.8% were caused by gram-negative agents (Pseudomonas aeruginosa accounting for 27%); and multidrug resistant organisms were identified in 43.4%. In the ventilator-associated pneumonia group, time on mechanical ventilation, time to mechanical ventilation weaning, hospital stays and intensive care unit stays were all longer (p < 0.001). In addition, atelectasis, acute respiratory distress syndrome, pneumothorax, sinusitis, tracheobronchitis and infection with multidrug resistant organisms were more common in the ventilator-associated pneumonia group (p < 0.05). Mortality rates in the intensive care unit were comparable to those observed in the hospital infirmary. Associations between ventilator-associated pneumonia and various factors are expressed as odds ratios and 95% confidence intervals: acute sinusitis (41.1; 3.4-441); > 10 days on mechanical ventilation (7.9; 4.1-14.2); immunosuppression (4.3; 1.3-14.3); acute respiratory distress syndrome (3.5; 1.4-9.0); atelectasis (3.8; 1.2-7.3); cardiac arrest (0.19; 0.05-0.66); and upper gastrointestinal tract bleeding (0.05; 0.009-0.62). The variables found to be associated with in-hospital death were as follows: chronic renal failure (26.1; 1.9-350.7); previous intensive care unit admission (15.6; 1.6-152.0); simplified acute physiologic score II > 50 (11.9; 3.4-42.0); and age > 55 years (4.4; 1.6-12.3). CONCLUSION: Ventilator-associated pneumonia increased the time on mechanical ventilation and the number of complications, as well as the length of intensive care unit and hospital stays, but did not affect mortality rates.

American Thoracic Society; Infectious Diseases Society of America. Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia. Am J Resp Crit Care Med. 2005;171(4):388-416.
National Nosocomial Infections Surveillance (NNIS) System Report: data summary from January 1992-April 2000, issued June 2000. Am J Infect Control. 2000;28(6):429-48.
Uchino S, Kellum JA, Bellomo R, Doig GS, Morimatsu H, Morgera S, et al. Acute renal failure in critically ill patients. A multinational, multicenter study. JAMA. 2005;294(7):813-8.