Noninvasive positive-pressure ventilation and ventilator-associated pneumonia.

There is much interest in the use of noninvasive positive-pressure ventilation (NPPV) to prevent intubation and afford a survival benefit for patients. The risk of pneumonia in patients receiving NPPV has been reported in 12 studies. Compared to patients receiving invasive mechanical ventilation (4 studies), the pneumonia rate is lower with the use of NPPV (relative risk [RR] 0.15, 95% confidence interval [CI] 0.04 to 0.58, p = 0.006). Compared to patients assigned to invasive mechanical ventilation (3 studies), in which some of the patients assigned to NPPV did not respond and were eventually intubated, there was also a benefit for the use of NPPV (RR 0.24, 95% CI 0.08 to 0.73, p = 0.01). In studies in which patients assigned to NPPV were compared to patients assigned to standard therapy (5 studies), in which some of the patients in each group were eventually intubated, there was benefit shown for the use of NPPV (RR 0.56, 95% CI 0.31 to 1.02, p = 0.06). When this meta-analysis is repeated without the results of the negative study for NPPV (extubation failure), there is a stronger benefit in support of NPPV to decrease the risk of pneumonia in the remaining 4 studies (RR 0.38, 95% CI 0.20 to 0.73, p = 0.003). A meta-analysis combining the results from the 12 studies reviewed shows a strong benefit for NPPV (RR 0.31, 95% CI 0.16 to 0.57, p = 0.0002). One randomized controlled trial of continuous positive airway pressure compared with standard treatment in patients who developed acute hypoxemia after elective major abdominal surgery reported a lower rate of pneumonia with continuous positive airway pressure (2% vs 10%, RR 0.19, 95% CI 0.04 to 0.88, p = 0.02). In patients who are appropriate candidates for NPPV or continuous positive airway pressure, the available evidence suggests a benefit in terms of a lower risk of pneumonia. Perhaps "endotracheal-tube-associated pneumonia" is a better term than "ventilator-associated pneumonia."