Physiological variables and modified Wood clinical asthma score (m-WCAS) at 1 h and after 6 and 12 h after randomisation according to group
| HFNC | Control | Mean difference (95% CI) | p-value | |
| Subjects n | 133 | 135 | ||
| 1 h | ||||
| fR breaths·min−1 | 46±13 | 50±13 | −4. (−7.5–−0.9) | 0.01 |
| HR bpm | 151±18 | 151±16 | 0.3 (−3.9–4.6) | ns |
| SpO2 % | 97±2 | 97±3 | 0.02 (−0.6–0.7) | ns |
| FiO2# or oxygen flow rate¶ | 25±5% | 0.5±0.4 L·min−1 | NA | |
| m-WCAS change | −0.098±0.22 | −0.036±0.23 | −0.06 (−0.12–−0.004) | <0.01 |
| Apnoea events | 1 | 1 | ND | |
| 6 h | ||||
| fR breaths·min−1 | 45±13 | 49±15 | −3.6 (−7.2–0.004) | 0.05 |
| HR bpm | 152±17 | 151±18 | 1.2 (−3.1–5.6) | ns |
| SpO2 % | 97±2 | 97±2 | −0.04 (−0.6–0 .5) | ns |
| PtCO2 mmHg | 44 ±7 | 48±10 | −3.6 (−8.5–1.2) | ns |
| FiO2# or oxygen flow rate¶ | 26±6% | 0.5±0.3 L·min−1 | NA | |
| m-WCAS change | −0.16±0.35 | 0.11±0.31 | −0.05 (−0.1–0.03) | ns |
| Apnoea events | 0 | 0 | ND | |
| 12 h | ||||
| fR breaths·min−1 | 42±13 | 47±14 | −4.8 (−8.3–−1.2) | 0.01 |
| HR bpm | 146±18 | 145±18 | 1.5 (−3.1–6.1) | ns |
| SpO2 % | 97±2 | 97±2 | −0.3 (−0.9–0.2) | ns |
| FiO2# or oxygen flow rate¶ | 25±5% | 0.5±0.4 L·min−1 | NA | |
| m-WCAS change | −0.23±0.31 | −0.15±0.38 | −0.07 (−0.1–0.02) | ns |
Data are presented as n, mean±sd or n (%), unless otherwise stated. HFNC: high-flow nasal cannula; fR: respiratory frequency; HR: heart rate; SpO2: pulse oximetry-measured oxygen saturation; FiO2: inspiratory oxygen fraction; PtCO2: transcutaneous carbon dioxide tension; ns: nonsignificant; NA: not applicable; ND: not determined. #: HFNC group; ¶: control group.