Table 3

Outcomes

OutcomeNHF manual N=10NHF automatic N=10Difference (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 changesN/A72 103 (15118)N/AN/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.