Table 2. Initial Intervention Details, Prone Positioning, and Clinical Conditions Prior to Tracheal Intubation.
| Continuous positive airway pressure (n = 380) |
High-flow nasal oxygen (n = 418) |
Conventional oxygen therapy (n = 475) |
|
|---|---|---|---|
| Initial intervention details and prone positioning | |||
| Continuous positive airway pressure | |||
| Positive end-expiratory pressure, mean (95% CI), cm H20 | (n = 304) 8.3 (8.1-8.5) |
NA | NA |
| Delivery device, No. (%) | NA | NA | |
| Noninvasive ventilationa | 147 (38.7) | NA | NA |
| Continuous positive airway pressure | 173 (45.5) | NA | NA |
| Otherb | 24 (6.3) | NA | NA |
| Initial flow for high-flow nasal oxygen, mean (95% CI), L/min | NA | (n = 323) 52.4 (51.4-53.5) |
NA |
| Treatment delivery duration, mean (SD), d | (n = 340) 3.5 (4.6) |
(n = 378) 3.7 (4.1) |
NA |
| Awake and in prone position, No./total (%)c | 207/327 (63.3) | 243/341 (71.3) | 252/374 (67.4) |
| Clinical condition prior to tracheal intubationd | |||
| Alert (conscious), No./total (%) | 72/80 (90.0) | 91/103 (88.3) | 112/122 (91.8) |
| Respiratory rate, median (IQR), /min | (n = 73) 34 (26-39) |
(n = 86) 28 (24-37) |
(n = 103) 30 (25-38) |
| Fio2, median (IQR) | (n = 88) 0.80 (0.65-0.98) |
(n = 100) 0.90 (0.70-0.99) |
(n = 117) 0.90 (0.80-0.98) |
| Spo2, median (IQR), % | (n = 86) 92.0 (89.0-95.0) |
(n = 100) 92.0 (88.0-94.0) |
(n = 122) 92.0 (88.0-93.0) |
| Ratio of Spo2 to Fio2, median (IQR), % | (n = 81) 118.8 (95.9-146.7) |
(n = 89) 103.4 (92.6-135.7) |
(n = 109) 98.0 (92.0-116.3) |
| Pao2, median (IQR), mm Hg | (n = 69) 66.0 (57.0-81.8) |
(n = 71) 63.0 (56.3-72.8) |
(n = 94) 64.5 (54.0-77.3) |
| Ratio of Pao2 to Fio2, median (IQR), mm Hg | (n = 65) 89.0 (69.5-111.0) |
(n = 65) 75.0 (60.0-98.1) |
(n = 84) 76.0 (60.0-98.0) |
| Paco2, median (IQR), mm Hg | (n = 70) 43.1 (34.5-49.5) |
(n = 76) 36.8 (30.8-46.1) |
(n = 97) 40.5 (34.5-47.3) |
Abbreviations: Fio2, fraction of inspired oxygen; NA, not applicable; Spo2, oxygen saturation as measured by pulse oximetry.
a
In continuous positive airway pressure mode.
b
Classified by hospital site as “other” and included noninvasive ventilation device in continuous positive airway pressure mode (n = 17) or the specific type of continuous positive airway pressure device was missing (n = 7).
c
Use of prone positioning was recorded during follow-up and was defined as any use during the hospital stay (both prior to and after randomization). Does not include use of prone positioning after tracheal intubation.
d
Data reflect the worst physiological levels within the 60 minutes prior to undergoing tracheal intubation.