A prospective and randomized study for improvement of acute asthma by non-invasive positive pressure ventilation (NPPV)

Abstract

Objective: We hypothesized that non-invasive positive pressure ventilation (NPPV) would improve an acute asthma attack in mild to moderate cases without bronchodilator therapy.

Methodology: A total of 44 eligible patients with acute asthma of mild to moderate severity who had acute attacks were randomly allocated to a NPPV (n=30) or control group (n=14). Both groups received intravenous infusion of hydrocortisone prior to the study. Patients in the NPPV group were divided into two subgroups at random: a high- (n=16) and a low-pressure group (n=14). The former had a fixed expiratory positive airway pressure and inspiratory positive airway pressure of 6 cmH2O and 8 cmH2O, respectively, while the latter had levels of 4 cmH2O and 6 cmH2O, respectively. Effects on the following variables were assessed: FEV(1), oxygen saturation, heart rate, respiratory rate, scores of accessory muscle use and wheezing by auscultation, modified Borg scale score, and mean intra-airway pressure on the monitor.

Results: A total of 26 patients completed the study in the NPPV group. The mean percent change in FEV(1) significantly improved after 40 minutes in the high-pressure group compared with that in the control group (p<0.0001). Similar significant improvements in modified Borg scale score and physical examination findings were observed in the high- and low-pressure groups. None of the patients required re-hospitalization or return to the emergency room in either the NPPV or control group.

Conclusion: We conclude that higher inflation pressure on NPPV led to clinical improvement in patients with acute asthma attacks of mild to moderate severity.