First author, published year | Study design | Study setting | Study location | Enrollment period | Total sample size (prone/non-prone) | Age (year, IQR or SD) (prone/non-prone) | Male (%) (prone/non-prone) | Oxygen therapy methods | Proning protocol | Location of proning | Proning duration in prone group | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Daily | Total | |||||||||||
Ehrmann [22] | RCT | Multicenter | Canada, France, Ireland, Mexico, USA, Spain | 2020.4.2.–2021.1.26 | 1121 (564/557) | 61.5 (13.3)/60.7 (14.0) | 67/66 | HFNC | As long and as frequently as possible each day | ICU, Ward, ER | 5 (IQR 1.6–8.8) h | NR |
Jayakumar [25] | RCT | Multicenter | India | NR | 60 (30/30) | 54.8 (11.1)/57.3 (12.1) | 83.3/83.3 | Nasal prongs, face mask, non-rebreather mask, HFNC, or NIV | ≥ 6 h/day (cumulative) | ICU |  ≥ 6 h in 43% of intervention group | NR |
Kharat [26] | RCT | Single center | Switzerland | 2020.4.6.–2020.4.25 | 27 (10/17) | 54 (14)/60 (11) | 60/65 | Nasal cannula | ≤ 12 h/day | Ward | 295 (SD 216) m | NR |
Rosén [27] | RCT | Multicenter | Sweden | 2020.10.7.–2021.2.7 | 75 (35/39) | 66 (53–74)/65 (55–70) | 64/82 | HFNC, NIV | ≥ 16 h/day | Ward, ICU | 9.0 (IQR 4.4–10.6) h | 4.2 (1.7–5.7) d |
Taylor [28] | RCT | Single center | US | 2020.6.1.–2020.8.31 | 40 (27/13) | 56 (45–66)/60 (54–63) | 63/77 | Nasal cannula, MFNC | As long as possible and allowed to return to the supine position as necessary | Ward | NR | NR |
Fralick [23] | RCT | Multicenter | Canada, US | 2021.3.-2021.5 | 248 (126/122) | 59.5 (45–68)/54 (44–62) | 65/63 | Nasal cannula, mask, HFNC | Four sessions/day (up to 2 h/sessions), encouraged to sleep in pone position overnight | Ward | NR | From randomization to first 72 h: 6 (1.5–12.8) h, from 72 h to 7 d: 0 (0–12) h |
Gad [24] | RCT | Single center | Egypt | 2020.6.-2020.9 | 30 (15/15) | 49.0 (38–62)/46.0 (33–51) | 60.0/53.3 | High flow with non-rebreathing facemask | Each session for 1–2 h according to patient to tolerability with 3 h apart during waking hours | Critical care isolation | NR | NR |
Ibarra-Estrada [11] | RCT | Multicenter | Mexico | 2020.5.5.–2021.1.26 | 430 (216/214) | 58.6 (15.8)/58.2 (15.8) | 61.1/58.9 | HFNC | As long as possible | Intermediate or intensive care unit | 4 sessions/d (3–5) 3.4 (3–3.6) h/session | 9.4 (5.6–12.9) h for 6 (3.7–9) ds |
Alhazzani [12] | RCT | Multicenter | Multicountry | 2020.5.19–2021.5.13 | 400 (205/195) | 56.8 (12.5)/58.3 (13.2) | 73/69 | HFNC, LFNC, NPPV | 8 h/d–10 h/d with 2 to 3 breaks (1–2 h each), if needed | ICU or a monitored acute care unit | NR | 3 (1–5) d |
Musso [30] | NRCT | Single center | Italy | Int 2020.12.16.–2021.5.30. Cont 2020.4.1.–2020.12.15 | 243 (81/162) | 68 (60–75)/69 (61–78) | 76/72 | NIV | As long as possible, at least 1 session/day lasting ≥ 8 h scheduled overnight | Subintensive care unit | 12.2 (10.1–13.8) h, 2 session/d | 6 (5–8) d |
Qian [29] | NRCT | Multicenter | US | 2020.5.13.–2020.12.11 | 501 (243/258) | 61.6 (15.4)/60.3 (15.2) | 56.6/56.8 | HFNC, LFNC, NIV | Encouraged as often and consistently as possible | NR | 4.2 (1.8–6.7) h | NR |
Ferrando [32] | Prospective cohort study | Multicenter | Spain, Andorra | 2020.3.12.–2020.6.9 | 199 (55/144) | 60.0 (54.0–70.0)/63.0 (55.0–71.0) | 75.9/72.7 | HFNC |  > 16 h regardless of the number of sessions | ICU | NR | NR |
Ni [5] | Prospective cohort study | Single center | China | 2020.1.31.–2020.2.15 | 52 (17/35) | 60 (12)/64 (12) | 64.7/60 | NR | ≥ 4 h/day for 10 days | Provisional ICU | NR | NR |
Zang [35] | Prospective cohort study | Single center | China | 2020.2.1.–2020.4.30 | 60 (23/37) | 63 (59–71)/66 (60–72) | 56.5/70.3 | O2 storage mask | 1–2 h/session, 3–4 sessions/day for more than 5 consecutive days | NR | NR | 13.4 (SD 8.0) h |
Bahloul [7] | Prospective cohort study | Single center | Tunisia | 2020.9.1.–2020.12.4 | 38 (21/17) | 61 (10)/60 (12) | 76.2/NR | Facial mask, HFNC | 2–4 h followed by 2 h of supine positioning during the day, and to sleep in a proning at night, when possible | ICU | NR | NR |
Esperatti [31] | Prospective cohort study | Multicenter | Argentina | 2020.6.–2021.1 | 335 (187/148) | 57 (47–66)/66.5 (56.5–75) | 76/72 | HFNC | ≥ 6 h/day, no time limits for prone position | ICU | 12 (IQR 9–16) h | 5 (IQR 3–8) d |
Sryma [34] | Prospective cohort study | NR | India | NR | 45 (30/15) | 50.9 (10.1)/57.5 (12.2) | 96.7/60 | NIV, HFNC, COT | ≥ 2 h/session, target duration of 8 h/day | NR | 7.5 (range 4–12) h on the first day | NR |
Pierucci [33] | Prospective cohort study | Single center | Italy | 2020.3.11.–2020.4.30 | 32 (16/16) | 59 (11)/70 (15) | 81/62 | Int: spontaneously breathing Cont: HFNC, CPAP, NIV | As long as possible with intervals for meals and other personal care |  |  |  |
Jagan [39] | Retrospective cohort study | Single center | US | 2020.3.24.–2020.5.5 | 105 (40/65) | 56.0 (14.4)/65.8 (16.3) | 50/56.9 | Non-intubation | ≥ 1 h/day for at least 5 sessions, ≥ 1 h/overnight | NR | NR | NR |
Padrão [42] | Retrospective cohort study | Single center | Brazil | 2020.3.1.–2020.4.30 | 166 (57/109) | 51.8 (13)/61.4 (13.6) | 70/66 | Nasal cannula, venturi mask, non-rebreather mask | ≥ 4 h in the first session, stimulated twice daily to maintain proning | NR | First session < 1 h 6%, 1–2 h 14%, 2–3 h 12%, 3–4 h 10%, > 4 h 58% | NR |
Barker [37] | Retrospective cohort study | Single center | UK | 2020.3.26.–2020.6.26 | 20 (10/10) | 59 (55–63)/65 (55–71) | 60/60 | NIV (Int 90%, Con 70%) | 30 m–2 h, repeated as many times as comfortable | ICU | NR | 120 (IQR 76–161) m, 4 (IQR 1–7) sessions/patient |
Jouffroy [6] | Retrospective cohort study | Multicenter | France | 2020.2.20.–2020.4.24 | 379 (40/339) | 59.5 (56–64)/62 (53–69) | 90/75.2 | HFNC | 3–6 h/session, twice a day | ICU | NR | 2.5 (IQR 1.6–3.4) d, 3 (IQR 2–5) sessions |
Loureiro-Amigo [8] | Retrospective cohort study (SEMI-COVID-19) | Multicenter | Spain | 2020.3.1.–2020.8.31 | 163 (60/103) | 66.57 [59.2–72.4]/70.81 [60.6–74.2] | 71.7/68.9 | Venturi masks, rebreathing masks | NR | Ward | NR | NR |
Prud’homme [44] | Retrospective cohort study | Multicenter | France | 2020.3.20–2020.4.20 | 96 (48/48) | 62 (11)/61 (18) | 77.1/64.6 | COT, HFNC | ≥ 3 h/day during 3 consecutive days, 1 to 12 h/session | Non-ICU | 3–8 h in 67%, > 5 h in 38% of intervention group | 6.9 (SD 5.2) d |
Shelhamer [9] | Retrospective cohort study | Single center | US | 2020.3.25.–2020.5.2 | 261 (62/199) | 60.0 (54.3–66.5)/66.0 (55.0–74.5) | 67.7/60.3 | IMV | ≥ 16 h in the afternoon, supine position the following morning | Traditional ICU, Converted floor ICU | NR | NR |
Stilma [45] | Retrospective cohort study | Multicenter | Netherlands | 2020.3.1.–2020.6.1 | 734 (438/296) | Without indication for proning 65.0 (10.3)/64.2 (11.4) With indication for proning 62.6 (11.2)/66.6 (9.1) | 72.6/73.3 | IMV | NR | ICU | 15.0 (IQR 10.5–21.0) h | 3 (2–3) d |
Tonelli [46] | Retrospective cohort study | Multicenter | Italy | 2020.3.1.–2020.6.1 | 114 (38/76) | 61 (32 − 75)/70 (33 − 80) | 66/73 | HFNC, CPAP, NIV | ≥ 3 h before back to supine | ICU | NR | NR |
Perez-Nieto [43] | Retrospective cohort study (APRONOX study) | Multicenter | Mexico, Ecuador | 2020.5.1.–2020.6.12 | 827 (505/322) | 53.4 (13.9)/55.8 (14.5) | 73.3/71.4 | LFNC, HFNC or a non-rebreather mask | ≥ 2 h continuously | ICU 13% non-ICU 87% | NR | 12 (IQR 8–24) h |
Koike [40] | Retrospective study | Single center | Japan | Int: 2020.10.1.–2020.12.1. Cont: 2020.12.1.–2020.3.31 | 58 (27/31) | 71 (55–77)/63 (49–70) | 90/87 | Simple O2, HFNC, NPPV | Discontinued if the patient developed intolerable respiratory distress, tachypnea > 35 bpm, or new unacceptable back pain during proning | ICU | 2 (2–3) sessions/d 180 (120–240) m | 13 (7–16) d |
Altinay [36] | Retrospective study | Single center | Turkey | 2020.3.15.–2020.6.15 | 48 (25/23) | 62.4 (10.9)/72.6 (10.1) | 44/39.1 | Nonrebreather mask oxygen | 18 h intermittently in a day | ICU | NR | NR |
Numata [41] | Retrospective study | Multicenter | Japan | 2020.7–2021.2 | 108 (54/54) | 68 (58–76)/70 (59–79) | 68.5/42.6 | HFNC | As long as possible, at least 3 times a day and for at least 6 h per day | Severe COVID-19 patient unit | NR | NR |
Chen [38] | Retrospective study | Single center | China | 2020.1.9.–2020.4.10 | 40 (17/23) | 69 (56–87)/72 (54–89) | 64.7/78.3 | IMV | NR | ICU | NR | NR |