Table.
Demographic details of the included RCTs
| Country | Study design | Enrolment location | Intervention* | Control* | Primary outcome | Follow-up time | Secondary outcome(s) | |
|---|---|---|---|---|---|---|---|---|
| Ehrmann et al (2021)11 | USA, Mexico, Canada, Ireland, France, and Spain | Multicentre RCT | ICU, intermediate care unit, emergency department, and general wards | 564 participants received awake prone positioning for as long and as frequently as possible; daily median duration 5·0 h (IQR 1·6–8·8) plus usual care | 557 participants received usual care (HFNC) | Treatment failure within 28 days of enrolment, defined as intubation or death | 28 days | Intubation; mortality; use of NIV; length of hospital stay; time to HFNC weaning in patients with treatment success; duration of IMV among intubated patients surviving to day 28; mortality in IMV patients; predefined safety outcomes; physiological response to awake prone positioning, including ROX index |
| Taylor et al (2021)12 | USA | Single-centre RCT | General ward | 27 participants received awake prone positioning plus usual care | 13 received usual care (room air, nasal cannula, HFNC, or NIV) | Outcomes relative to the successful implementation of a future definitive RCT | Until discharge or death | S/F; time on S/F <315; receipt of intensive care; oxygen flow >6 L/min; intubation; hospital length of stay; hospital mortality at 48 h; safety outcomes |
| Johnson et al (2021)13 | USA | Single-centre RCT | General ward | 15 participants received awake prone positioning every 4 h, with a duration of 1–2 h or as long as tolerated; total median duration 1·6 h (IQR 0·2–3·1) plus usual care | 15 participants received usual care (room air or nasal cannula) | The change in P/F at 72 h after admission | 28 days | The change in P/F at 48 h; the need for endotracheal intubation; ICU transfer; escalation in oxygen delivery system; the length of stay; ventilator-free days; in-hospital mortality |
| Rosén et al (2021)14 | Sweden | Multicentre RCT | ICU and general ward | 36 participants received awake prone positioning for at least 16 h/day; daily median duration 9·0 h (IQR 4·4–10·6) plus usual care | 39 participants received usual care (HFNC or NIV) | Intubation within 30 days after enrolment | 30 days | Duration of awake prone positioning; use of NIV; time to NIV for patients included with HFNC; use of vasopressors or inotropes; CRRT; ECMO; ventilator-free days; days free of NIV or HFNC; hospital and ICU length of stay; 30-day mortality; WHO-ordinal scale for clinical improvement at 7 and 30 days; adverse events |
| Kharat et al (2021)15 | Switzerland | Single-centre RCT | General ward | 10 participants received awake prone positioning, self-proning for 12 h/day and alternate body positioning every 4 h; total median duration 4·9 h (SD 3·6) plus usual care | 17 participants received usual care (nasal cannula) | Oxygen needs assessed by nasal cannula oxygen flow at 24 h | 28 days | S/F ratio at 24 h; respiratory and heart rate at 24 h; patient trajectory (transfer to critical care unit) and potential intervention-related adverse effects as defined by neck pain; position-related discomfort and gastro-oesophageal reflux; intubation; death at 28 days |
| Jayakumar et al (2021)16 | India | Multicentre RCT | ICU | 30 participants received awake prone positioning for at least 6 h/day plus usual care | 30 participants received usual care (nasal cannula, face mask, non-rebreather mask, HFNC, or NIV) | The proportion of patients adhering to the protocol | Until discharge or death | Proportion of patients requiring escalation of respiratory support; number of h prone and maximum h of continuous prone positioning in a day; the length of stay in ICU; ICU mortality; adverse events |
| Gad et al (2021)17 | Egypt | Single-centre RCT | ICU | 15 participants received awake prone positioning for 1–2 h each session 3 h apart during waking h for the first 3 days plus usual care | 15 participants received usual care (non-rebreather mask) | Improvement of oxygenation and avoidance of intubation within the first 3 days of critical care admission | .. | ICU stay and hospital stay |
| Fralick et al (2021)18 | Canada, USA | Multicentre RCT | General ward | 126 participants received awake prone positioning four times per day (up to 2 h for each session) and they were encouraged to sleep in the prone position overnight; total median duration 6 h (IQR 1·5–12·8) in the first 72 h and 0 h (IQR 0–12) from 72 h to 7 days; plus usual care | 122 participants received usual care (nasal cannula, venturi mask, HFNC) | A composite of in-hospital death, mechanical ventilation, or worsening respiratory failure defined as requiring at least 60% fraction of inspired oxygen for more than 24 h | 30 days | The components of the composite analysed individually; time spent in the prone position; change in S/F; time to recovery (defined as being on room air for at least 24 h); time to discharge from hospital; and the rate of serious adverse events |
| Garcia et al (2021)19 | USA | Multicentre RCT | General ward | 159 participants received awake prone positioning in up to four 1–2 h daily sessions, and up to 12 h nightly plus usual care | 134 participants received usual care (room air, nasal cannula, mask, or HFNC) | Progression of acute respiratory failure, composite outcome of either respiratory deterioration (ie, progression to non-rebreather mask, HFNC, NIV, IMV, or requiring an increase in oxygen ≥2 L/min compared with their baseline) or admission to the ICU | 14 days (or until discharge or death) | Respiratory deterioration; admission to the ICU; receipt of IMV; hospital mortality; diagnosis of ARDS; median self-reported dyspnoea (Borg Score); safety outcomes; and compliance with awake prone positioning |
| Harris et al (NCT04853979) | Qatar | Multicentre RCT | General ward | 31 participants received awake prone positioning for at least 3 h/day and up to 16 h/day plus usual care | 30 participants received usual care (nasal cannula, non-rebreather mask, HFNC, or NIV) | Escalation of respiratory support within the 30 days of the study | 30 days | Incidence of intubation within 30 days of enrolment; use of nasal prongs, Hudson mask, non-rebreather mask, NIV, and IMV in each group in the first 3 days of the study; physiological response to prone averaged over days 1–3; P/F or S/F ratio and ROX index at baseline, 1 h after the first prone and daily for 4 days; length of time tolerating proning; 28-day mortality; length of stay in ICU and hospital; duration of IMV; displacement of devices; adverse events |
RCT=randomised controlled trial. ICU=intensive care unit. HFNC=high flow nasal cannula. NIV=non-invasive ventilation. IMV=invasive mechanical ventilation. S/F=ratio of pulse oxygen saturation to fraction of inhaled oxygen. S/F=ratio of pulse oximetric saturation to fraction of inhaled oxygen. P/F=ratio of partial pressure of arterial oxygen to fraction of inhaled oxygen. ROX index= ratio of S/F to respiratory rate. CRRT=continuous renal replacement therapy. ECMO=extracorporeal membrane oxygenation. ARDS=acute respiratory distress syndrome.
*
For further baseline characteristics of the participants please see the full table in the appendix (appendix pp 46–47)