Table 3.
Outcomes
| Outcome | NHF manual N=10 | NHF automatic N=10 | Difference (95% CI) | P value |
| Median (IQR) | Rank based | |||
| Time in target SpO2 range (%) | 71 (59.4 to 88.3) | 96.2 (95.2 to 97.8) | 24.2 (7.9 to 35) | <0.001 |
| Time in target SpO2 range—all SQ (%) | 69 (52 to 82.4) | 93.3 (89.7 to 97.1) | 24.3 (11.7 to 37.6) | <0.001 |
| Time ≥2% above range (%) | 5.6 (9) | 0.8 (2.2) | −1 (−8.2 to −0.04) | 0.017 |
| Time ≥4% above range (%) | 0 (0 to 0.4) | 0 (0 to 0) | −0.01 (−0.25 to 0) | 0.021 |
| Time ≥2% below range (%) | 1.5 (0.5 to 8.2) | 0.1 (0 to 0.2) | −2.4 (−11.5 to 0.3) | 0.05 |
| Time ≥4% below range (%) | 0 (0 to 0.3) | 0 (0 to 0) | −0.25 (−4.8 to 0.4) | 0.31 |
| Time ≥8% below range (%) | 0.1 (0 to 1.6) | 0.1 (0 to 0.2) | −0.01 (−1.5 to 0.1) | 0.54 |
| Mean (SD) | Mean difference* | |||
| Mean heart rate (beats/min) | 78 (13.1) | 87.9 (15.1) | 0.5 (−8.2 to 9.1) | 0.91 |
| Mean FiO2 (%) | 29.4 (3.5) | 29.1 (2) | 1.5 (−0.5 to 3.4) | 0.13 |
| Minimum FiO2 (%) | 25.3 (4.2) | 23.3 (2.6) | −0.5 (−3.5 to 2.6) | 0.76 |
| Maximum FiO2 (%) | 32 (4.3) | 37.1 (2.7) | 7.1 (4.6 to 9.7) | <0.001 |
| No of manual FiO2 changes† | 4.8 (5.4) | 4 (3.9) | −0.8 (−5.3 to 3.7) | 0.35 |
| No of automatic FiO2 changes | N/A | 72 103 (15118) | N/A | N/A |
*Adjusted for baseline, other than number of manual FiO2 changes.
†In the automatic group the number of manual FiO2 changes refers to the number of times the FiO2 limits were changed by nursing staff.
FiO2, fractional inspired oxygen; NA, not available; NHF, nasal high-flow.