Value and Safety of High Flow Oxygenation in the Treatment of Inpatient Asthma: A Randomized, Double-blind, Pilot Study

This study was aimed to compare the value and safety of high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) in patients with asthma exacerbation. In this randomized double-blind study, forthy patients with moderate-to-severe asthma exacerbations, aged 18 years or older were enrolled. Patients were randomly assigned to receive either HFNC or COT for 24 hours. Dyspnea scale, O2 saturation, spirometer indexes, respiratory and heart rate, and arterial blood gas (ABG) were compared within 2 and 24 hours of intervention. Dyspnea scale decreased significantly from 7.58±1.04 to 6.45±0.51 (p=0.000), and from 7.84±1.7 to 6.89±0.9 (p=0.049) within 2 hours in HFNC and COT groups, respectively. In the HFNC group, forced expiratory volume in one second (FEV1) was 1.48 ±0.94 L at the time of admission and increased to 1.61±0.66 L (p=0.19) and 1.82±0.92 L (p=0.003) after 2 and 24 hours of experience, respectively. In addition, in the COT group, FEV1 increased from 1.43±0.65 L to 1.46±0.53 L and 1.64±0.6 L in the respective time-points, (p=0.071, 0.079). PaO2 and O2 saturation increased significantly in both groups during the first 2 hours. Two patients in the HFNC group had the complaint of nasal irritation and the device-produced heat; while one patient in the COT group needed more respiratory care. HFNC could be a therapeutic option for asthma exacerbation among adult patients after considering the patient's selection.