Background: Despite improvements in asthma medication, Intubation is deemed necessary in severe asthma with its complications. Non-invasive ventilation is the evolving method to manage acute respiratory failure in these patients. But the effect of non-invasive ventilation is unclear and there are debates regarding its safety.
Aims: To assess the effect of NIV in acute asthma.
Design: Two years of a prospective interventional study.
Methods: Patients with acute asthma were classified into two groups: 1 (standard medical therapy alone) and group 2 (addition of NIV to medical therapy). Demographic, physiological, functional data and blood gas results were recorded. The primary outcomes were the improvement in forced expiratory volume in the first second (FEV1), heart rate, respiratory rate, PaO2, PaCO2, and pH. The secondary outcomes were the need for invasive mechanical ventilation, intensive care unit (ICU) and hospital stay.
Results: Ninety patients with severe acute asthma (57 females and 33 males, mean ± SD age 52 ± 15.7 y, FEV1 < 60% of predicted). APACHE II score was higher in NIV group. There was a significant improvement after 6 hours in respiratory rate (16.6 ± 3.7), heart rate (95.8 ± 11.3), and PaO2 (88.09 ± 20.2). After 1h and 24 hours > 50% improvement in FEV1 was significantly greater in the NIV group. The time needed to alleviate accessory muscle use was shorter in the NIV group. The failure rate was more with group1 (4 patients needed intubation, but only 2 patients in group 2). There was no mortality in any group of our study.
Conclusion: The use of NIV was effective in improving oxygenation, heart rate, and respiratory rate, shorten the length of hospital and ICU stay in acute severe asthma.