This randomized controlled study found the use of nasal high flow therapy to be advantageous over conventional oxygen therapy in terms of providing respiratory support and oxygenation in adults with severe asthma and lower oxygen levels in the emergency ward.

This pilot study aimed to compare the effectiveness of nasal high flow (NHF) and conventional oxygen therapy (COT) in the improvement of dyspnea (shortness of breath) in acute severe asthma in the emergency department.      

Thirty-seven patients aged ≥ 18 years with acute severe asthma and lower oxygen levels than normal (hypoxemia) were recruited. These patients were arbitrarily allotted to receive either COT (18 patients) or NHF (19 patients) for 2 hours.

Comparison of effects of the interventions used on the degree of dyspnea evaluated via the modified Borg scale (MBS) was the primary outcome. Comparisons of the numeric rating scale (NRS) of dyspnea, the dyspnea scale evaluating accessory muscle use, vital signs, and blood gas outcomes comprised of secondary outcomes.

The intention-to-treat analysis encompassed 37 patients. Both groups had a baseline mean MBS of 7.8. The mean MBSs in patients receiving COT and NHF were 3.3 and 1.4, respectively at 120 minutes.

Similar trends followed in NRS and dyspnea score results to those of MBS. There were lower respiratory rates with the use of NHF. No between- or in-group differences in blood gas outcomes were noted.

NHF proved to be efficacious in decreasing the severity of dyspnea and respiratory rate in hypoxemic adult patients with asthma.