Utilization of mechanical ventilation for asthma exacerbations: analysis of a national database

Abstract

Background: The current frequency of noninvasive (NIV) and invasive mechanical ventilation use in asthma exacerbations (AEs) and the relationship to outcomes are unknown.

Methods: We used the Healthcare Cost and Utilization Project Nationwide Inpatient Sample to identify patients discharged with a principal diagnosis of AE. For each discharge, we determined whether NIV or invasive mechanical ventilation was initiated during the first 2 hospital days. Using multivariate logistic regression to adjust for potential confounders, we determined whether use of mechanical ventilation and in-hospital mortality changed between 2000 and 2008.

Results: The number of AEs increased by 15.8% from 2000 to 2008. The proportion of admissions for which invasive mechanical ventilation was used during the first 2 days decreased from 1.4% in 2000 to 0.73% in 2008, whereas NIV use increased from 0.34% to 1.9%. The adjusted mortality from AEs requiring NIV or invasive mechanical ventilation was unchanged from 2000 to 2008. The hospital stay was also unchanged.

Conclusions: There was a substantial increase in the use of mechanical ventilation, accompanied by a shift from invasive mechanical ventilation to NIV. Although we could not determine the clinical reasons for this increase, hospital stay and mortality were unchanged. A randomized trial is needed to determine whether NIV can improve outcomes in AEs before widespread adoption makes it impossible to conduct such a trial.

Keywords: asthma; intensive care unit; mechanical ventilation.

Fig. 1

Selection of asthma cases for this study. NIV = noninvasive ventilation.

Fig. 2

Utilization of noninvasive and invasive mechanical ventilation in asthma. Bars represent standard error. NIV = noninvasive ventilation; IMV = invasive mechanical ventilation; OSA = obstructive sleep apnea.