Prevalência e prognóstico dos pacientes com pneumonia associada à ventilação mecânica em um hospital universitário

Abstract

To determine the prevalence of ventilator-associated pneumonia in an intensive care unit, as well as to identify related factors and characterize patient evolution. This study evaluated 278 patients on mechanical ventilation for more than 24 hours in a university hospital. Ventilator-associated pneumonia developed in 38.1% of the patients, translating to 35.7 cases/1000 ventilator-days: 45.3% were caused by gram-negative agents (Pseudomonas aeruginosa accounting for 22%); 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 (38.8; 3.4-441); > 10 days on mechanical ventilation (7.7; 4.1-14.2); immunosuppression (4.3; 1.3-14.3); acute respiratory distress syndrome (3.5; 1.4-9.0); atelectasis (3.0; 1.2-7.3); cardiac arrest (0.18; 0.05-0.66); and upper gastrointestinal tract bleeding (0.07; 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). 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.