Objectives To study the role of non-invasive positive pressure ventilation (NIPPV) in management of acute severe asthma.
Study design Open randomised controlled trial.
Methods 50 patients of acute severe asthma having asthma for at least 1 year duration with exacerbation of less than 7 days duration, FEV1 <50% of predicted, respiratory rate of >25 breaths/min and pulse rate >110/min after half hour of 5 mg nebulised salbutamol were included in the study over 1 year. Patients with known COPD, history of smoking >10 years, HR >140/min, systolic BP <90 mm Hg, facial deformity, pulmonary oedema, pneumonia and pregnancy were excluded. Patients were divided into two groups A and B. All patients received nebulisation with salbutamol 5 mg and ipratropium bromide 0.5 mg and hydrocortisone 100 mg IV at zero hour and later 5 mg salbutamol with small volume oxygen driven nebuliser @ 6 l/min at 1, 2, 3, 5 h of the study. Group B patients were given NIV support in addition to medical therapy for 6 h. All patients received O2 at 6–8 l/min for 6 h. NIV and medical treatment were stopped after 6 h. Spirometry, ABG, respiratory rate (RR), accessory muscles of respiration (AMR) and Borg dyspnoea score were assessed at 0, 1, 3, 6 and 7th hour of study.
Results Out of 308 patients 246 were excluded because of non-fulfilment of inclusion criteria. Eight patients refused consent, three had pneumonia and claustrophobia to mask respectively. One patient deteriorated in Group A and was withdrawn. The use of accessory muscles of respiration (AMR) reduced significantly in group B at 3, 6 and 7 h (p<0.01), BORG dyspnoea score improved significantly (p<0.01) in group B after 1 h. There was no difference between two groups in terms of improvement in RR, HR, FEV1 and ABG. In group B, the mean IPAP and EPAP used was 14.32±0.945 and 7.16±0.472 cm of water, respectively.
Conclusion The use of NIPPV in patients with acute severe asthma though found to be useful in terms of faster resolution of dyspnoea and decrease in use of AMR but did not improve pulmonary functions significantly.