The role of noninvasive positive pressure ventilation in community-acquired pneumonia

Despite the increasing use of noninvasive positive pressure ventilation (NIV) in the treatment of critically ill patients with respiratory failure, its role in the treatment of severe community-acquired pneumonia (CAP) is controversial. The aim of this study was to assess the use of NIV in patients with CAP requiring ventilation who are admitted an intensive care unit.

A retrospective cohort study of all consecutive patients admitted to 3 tertiary care, university-affiliated, intensive care units from January 2007 to January 2012 with the principal diagnosis of CAP and requiring positive pressure ventilation was carried out. The primary outcome was acute hospital mortality. Univariable and multivariable analysis were performed to assess the association between mode of ventilation and death as well as factors associated with failure of NIV.

A total of 229 patients were admitted, with 20 patients excluded from the analysis because of do-not-resuscitate orders. Fifty-six percent of patients were initially treated with NIV. Of those, 76% failed NIV and required intubation and invasive ventilation. After adjusting for confounders, no difference in mortality was seen between patients who received NIV as first-line therapy in comparison with patients who received invasive ventilation (odds ratio [OR], 1.63; 95% confidence interval [CI], 0.81-3.28; P = .17). Multivariable analysis demonstrated a trend toward increased NIV failure for the patients who had higher Acute Physiology and Chronic Health Evaluation II scores (P = .07) and vasopressor use at 2 hours after initiation of positive pressure ventilation (OR, 7.5; 95% CI, 1.8-31.3, P = .006). In an adjusted analysis, patients who failed NIV had an increased odds of death when compared with patients who were treated with invasive ventilation (OR, 2.2; 95% CI, 1.0-4.8; P = .03).

Noninvasive pressure ventilation is frequently used in CAP but is associated with high failure rates. Mortality was not improved in the group of patients who received NIV as first-line therapy despite clinical characteristics that might have suggested a more favorable prognosis. Given the high rates of NIV use, high failure rates, and the hypothesis generating nature of the data in this study, further randomized studies are needed to better delineate the role of NIV in CAP.