Outcomes of Noninvasive Ventilation in Obese Patients With Acute Asthma Exacerbations

The role of noninvasive positive pressure ventilation (NIPPV) in acute asthma exacerbation is controversial. However, the outcome of NIPPV in obese patients with asthma during such exacerbation has not been well studied despite well-established relationship between obesity and asthma.

Does body mass index (BMI) play a role in the outcome of NIPPV during an acute exacerbation and does it predict of the success or failure of NIPPV?

The study was a retrospective analysis by design. The purpose of the study was to assess factors predicting the success or failure of NIPPV. The entire cohort was divided into 2 groups: patients who failed NIPPV and patients who did not. Univariate and multivariate regression analysis was used to predict the variables. Stepwise selection method was used to select variables for final regression model.

A total 96 patients were included in the study. Of those, 18 patients (18.9%) failed NIPPV and required endotracheal intubation (group 1). Rest (78.1%) did not fail NIPPV (group 2). Mean age of the study population was 48.8 years and 53% of patients were female. In the univariate analysis, the group that did not fail NIPPV (group 2) had significantly higher number of obese patients (47.9% versus 22.2%; P 0.013). Multivariate analysis showed significant association between BMI categories (BMI of 30 or more) and failure of NIPPV (odds ratio 0.26, 95% confidence interval, 0.08-0.85; P-value 0.017). Forced introduction of smoking status as a risk factor did not change the significance of association.

Despite the limitations of the study design and the sample size, our analysis showed that patients with high BMI (obese) fared well with NIPPV during acute asthma exacerbation. Because there are controversies on use of NIPPV during asthma exacerbation, larger-scale prospective studies are needed to better understand the role of NIPPV in obese patients with asthma during acute exacerbation.