Pneumonia is the leading infectious cause of hospitalization in US, resulting in more than 1 million admissions annually. Roughly 60% of patients with severe pneumonia develop acute respiratory failure and require invasive mechanical ventilation (IMV). Strong evidence supports the use of noninvasive mechanical ventilation (NIV) in patients with COPD or pulmonary edema, but data on its effectiveness in patients with pneumonia are conflicting.
For a study published in the Journal of Critical Care, my colleagues and I compared the outcomes of patients with pneumonia initially treated with NIV with those of patients initially treated with IMV using a large multihospital electronic medical record database that contains results of laboratory testing. We developed a propensity model for receipt of NIV and assessed the outcomes in a propensity-matched cohort. Among nearly 4,000 patients hospitalized with pneumonia who were ventilated, 28% were treated with NIV. Mortality rates were 15.8%, 29.8%, and 25.9.0% among patients treated with initial NIV, treated with initial IMV, or who failed NIV and had to be intubated, respectively. In the propensity matched analysis, the risk of death was 30% lower in patients treated with NIV than in those treated with IMV. However, in the subgroup analysis, we showed that NIV was beneficial only among patients with cardiopulmonary comorbidities. We also found that patients with pneumonia without coexistent COPD or heart failure were more likely to fail NIV than those with cardiopulmonary conditions (21.3% vs13.8%).
Our results suggest that NIV is efficacious only in pneumonia patients who also have comorbid COPD or heart failure. Careful monitoring is required when managing severe pneumonia with NIV.