Table 1.
Characteristics of studies examining awake prone positioning in non-intubated patients with hypoxemic respiratory failure due to COVID-19.
| Author | Study Type | N | Inclusion Criteria | Exclusion Criteria | Setting | Oxygen Delivery Mode | Prone Positioning Protocol | Study Outcome | Duration of Follow-up | Duration of Prone Positioning | Supine Oxygenation and Resp Rate (if available) mean (SD), median [IQR] |
Prone Position Oxygenation and Resp Rate (if available) mean (SD), median [IQR] | Intubation Rate, No. (%) | Adverse Event Reporting |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Coppo (2020) | PC | 56 | Age 18–75, confirmed COVID-19, hypoxemia consent | Pregnant, uncollaborative, altered mental status, NYHA < II, increased BNP, COPD on home NIV or O2, impending intubation | Non-ICU Medical units, ED, ICU | Helmet CPAP, Reservoir mask, Venturi mask | Assisted proning, encouraged to maintain x 3 h, Repeat up to 8 h/d | PaO2:FiO2 | Hospital discharge | Median 3 h [3, 4] Up to 7 sessions. |
PaO2:FiO2 180.5 (76.6) RR 24.5 (5.5) |
PaO2:FiO2 285.5 (112.9) RR 24.5 (6.9) |
18/56 (32) | 9% discomfort 4% worsening oxygenation 2% coughing 5 deaths (9%) |
| Golestani-Eraghi (2020) | PC | 10 | COVID-19, not mech ventilated, PaO2:FiO2 < 150 | Not reported | ICU | Helmet NIV | 2 h sessions | Not reported | Not reported | Mean 9 h | PaO2 46.3 (5.2) | PaO2 62.5 (4.6) | 2/10 (20%) | None reported 2 deaths (20%) |
| Moghadam (2020) | PC | 10 | COVID-19, not mech ventilated | Not reported | Non-ICU Medical unit | Not reported | Not reported | SpO2, RR, auxiliary muscle use | Hospital discharge | Not reported | SpO2 86% (0.7) | SpO2 96% (2.2) | 0/10 (0) | Not reported |
| Elharrar (2020) | PC | 24 | Hypoxemia, CT chest with COVID-19 and posterior lesions | Requiring intubation, altered consciousness | Non-ICU Medical unit | NP, facemask, HFNC | Single episode, no goal duration | Proportion of patients with PaO2 increase ≥20%from supine to PP | 10 days | 17% <1 h 21% 1–3 h 63% >3 h |
PaO2 72.8 (14.2) | PaO2 91 (27.3) 25% had ≥20% increase PaO2 |
5/24 (20.8) | 42% backpain 17% tolerated <1 h 17% required intubation within 72 h |
| Ng (2020) | PC | 10 | Hypoxemia | Drowsy, uncooper-ative, ophthalmic or cervical pathology, pregnancy, hemodyn-amic instability, FiO2 > 0.5 | Non-ICU Medical unit | NP, HFNC, or Venturi mask | 1 h sessions, 5 sessions/d spaced 3 h apart. Continued until on RA x 24 h |
Not reported | Median 8 days (range 2–19) | Median total duration 21 h (range 2–58) | SpO2 91.5 (range 88–95) | Not reported | 1/10 (10) | Discomfort, nausea, vomiting reported 1 death (10%) |
| Retucci (2020) | PC | 26 | COVID-19, spontane-ous breathing, GCS = 15, PaO2:FiO2 < 250 after 48 h Helmet CPAP | Requiring intubation, GCS < 15, SBP < 90, SpO2 < 90% on FiO2 > 0.8 | ICU | Helmet CPAP | Prone/lateral positioning based on CXR or CT scan, 1 h sessions. 39 sessions: 12 prone, 27 lateral |
Successful trial, defined as all 4 of: 1. decrease A-aO2 gradient ≥20%, 2. equal or reduced RR, 3. equal or reduced dyspnea 4. SBP ≥ 90 mmHg |
Not reported | 1 h | PaO2:FiO2 182.9 (43) A-aO2 207.1 [160.7–251.3] RR 23.7 (4.7) |
PaO2:FiO2 220 (64.5) A-aO2 184.3 [141.4–246.8] RR 23.1 (4.5) |
7/26 (27) | 39% of trials did not meet primary outcome. 25% of prone position trials failed 40% of lateral position trials failed 8% did not tolerate (both in lateral position) 5% discomfort 3% SBP < 90 mmHg 8% increased RR 2 deaths (8%) |
| Sartini (2020) | PC | 15 | Hypoxemia (SpO2 < 94%), FiO2 > 0.6 and CPAP 10 cm H2O | – | Non-ICU Medical Unit | NIV | Not reported | PaO2:FiO2, RR, patient comfort with NIV | 14 days | Median 3 h (IQR 1–6) | PaO2:FiO2 58–117** Supine RR: 21–31** |
PaO2:FiO2 114–122** PP: 18–27** |
1/15 (6.6) | 1 death (7%) |
| Thompson (2020) | PC | 29 | Confirmed COVID-19, Severe hypoxemia (RR > 30 and SpO2 < 93% on 6 L O2 by NP and 15 L by NRB | Altered mental status, inability to turn without help, immediate intubation needed, mild hypoxemia. | Step-down unit (interme-diate) | NP or NRB | Repeated episodes, up to 24 h per day, use a pillow under hips/pelvis. | Change in SpO2 at 1 h | Up to 49 days or to hospital discharge | Median 4 h (range 1–24) in not-intubated group, Median 6 h (range 1–24) in intubated group. |
SpO2 65–95%** | SpO2 90–100%** Median SpO2 improvement 7% [4.6–9.4] |
16/29 (55) | 13% refused 3 deaths (10%) |
| Tu (2020) | PC | 9 | COVID-19 confirmed, HFNC >2 days, PaO2:FiO2 < 150 | – | Not reported | HFNC | Repeated episodes, as long as tolerated | SpO2 PaO2 |
Hospital discharge, mean LOS 28 (10) d | Median 2 h [1–4] per session, median 5 [3–8] sessions | SpO2 90% (2) PaO2 69 (10) |
SpO2 96% (3) PaO2 108 (14) |
2/9 (22) | None reported 1 intubated patient required ECMO 0 deaths (0%) |
| Caputo (2020) | PC | 50 | Hypoxemia (SpO2 < 90%) | NIV use, DNR order | ED | NP or facemask | Not reported | SpO2 5 min after PP, intubation rate within 24 h | 3 days | Not reported | SpO2 84% [75–90] | SpO2 94% [90–95] | 13/50 (26.0) | 22% required intubation within 60 min |
| Zhang (2020) | PC | 23 | COVID-19, Hypoxemia (SpO2 < 90%), Age 18–80, consent | Need for intubation, inability to self position, basal lung disease, unstable spine, high ICP, severe burns, abdo surgery, abdo HTN, cranial injury, tracheotomy, immuno-suppresion, pregnant, imminent death. | Not reported | NP, HFNC, NIV | Evaluated muscle strength first, self position prone, 1-2 h sessions 3–4 times/day for 5 days. Vitals measured at 10 min and 30 min in PP | SpO2, RR, ROX | 90 days | Median 9 h [8–22] | SpO2 91.1 (1.5), RR 28.2 (3.1) ROX 3.35 (0.46) |
SpO2 95.5 (1.7) RR 24.9 (1.8) ROX 3.96 (0.45) |
8/23 (35) | 10 deaths (43%) |
| Bastoni (2020) | RC | 10 | Receiving helmet NIV, awake & able to prone | Need for rapid intubation & ICU, End-stage comorbid disease | ED | Helmet CPAP 10–20 cmH2O | Nurse assisted, Morphine infusion for sedation. | PaO2:FiO2, Lung US signs | Hospital discharge | 1 h | PaO2:FiO2 68 (5) | PaO2:FiO2 97 (8) No change in lung US findings |
6/10 (60) | 40% did not tolerate or refused. 4 deaths (40%) |
| Burton-Papp (2020) | RC | 20 | COVID-19, Hypoxemia, received CPAP or NIV | – | ICU | CPAP or NIV | Not described | ΔP/F | Hospital discharge | Median 3 [2] Median 5 cycles per patient [6.25] |
– | ΔPaO2/FiO2 + 28.7 [95%CI 18.7–38.6] ΔRR −0.98 [95%CI -2-0.04] |
7/20 (35) | None reported 2 intubated patients required ECMO 0 deaths |
| Cohen (2020) | RC | 2 | 52 Female 40 Male |
– | Non-ICU Medical unit | HFNC, NP | Self-prone as long as possible | – | Discharge from unit | 2–4 h per day | Patient 1. SpO2 90% on HFNC FiO2 1.0, RR 45 Patient 2. SpO2 92% on 4 L |
Patient 1. SpO2 100% on HFNC FiO2 1.0, RR 25 Patinet 2. SpO2 96% on 2 L |
0/2 (0) | None reported |
| Damarla (2020) | RC | 10 | Confirmed COVID-19, rapidly increasing O2 requiring ICU | Requiring intubation | ICU | NP or HFNC | Alternate prone/supine every 2 h, supervised first episode | SpO2, RR at 1 h | 28 d | 2 h | SpO2 94% [91–95] RR 31 [28–39] |
SpO2 98 [97–99] RR 22 [18–25] |
2/10 (20) | None 0 deaths |
| Despres (2020) | RC | 6 | COVID-19, PaO2:FiO2 ≤ 300 | Requiring intubation | ICU | NP, HFNC | As long as tolerated | PaO2:FiO2 | Not reported | Median 2 h [1–7] | PaO2:FiO2 183 [144–212] | PaO2:FiO2 168 [156–225] | 3/6 (50%) | Not reported |
| Dong (2020) | RC | 25 | COVID-19, Severe disease (RR ≥ 30, SpO2 ≤ 93% or PaO2:FiO2 〈300), or critical disease (Requiring ventilation, shock, organ failure) | Excluded patients who received PP but rapidly improved or who did not tolerate first session. | ICU | NP, Mask, HFNC, NIV | Daily session >4 h, nurse instructions, lateral positioning if PP not tolerated | Survival, intubation, PaO2:FiO2 | Hospital discharge | Mean 4.9 h (SD 3.1) | PaO2:FiO2 194 [164–252] RR 27 [26–30] |
PaO2:FiO2 348 [288–390] RR 22 [20−22] |
0/25 | 16% Sternal pain 4% Scrotal pain 4% Lumbago 4% Pruritis 0 deaths |
| Froelich (2020) | RC | 3 | Confirmed COVID-19 | – | Not reported | NP. Face Mask, HFNC | Varied positions, supine, lateral, prone, ergonomic prone. | SpO2 | Not reported | <30 min | Patient 1. SpO2 94% on 4 L Patient 2. SpO2 95% on 6 L Patient 3. SpO2 91% on 15 L |
Patient 1. SpO2 97% on 4 L Patient 2. SpO2 97% on 6 L Patient 3. SpO2 95% on 15 L (lateral position only) |
0/3 (0) | 33% Hip and back pain 33% Inability to maintain prone position due to jaw dislocation |
| Huang (2020) | RC | 3 | SpO2 < 92% on ≥6 L or PaO2:FiO2 < 200, bilateral opacities, RR < 30 | Accessory muscle use, Contraindic-ations (cervical instability, pregnancy) | Not reported | HFNC, Venturi mask | Four 2 h sessions daily | PaO2:FiO2 | Up to 6 days | Not reported | Patient 1. PaO2:FiO2 84.8 Patient 2. PaO2:FiO2 160 Patient 3. PaO2:FiO2 60.6 |
Patient 1. PaO2:FiO2 114 Patient 2. PaO2:FiO2 169 Patient 3. PaO2:FiO2 133 |
1/3 (33) | Not reported |
| Paul (2020) | RC | 2 | 42 Male 35 Male |
– | ICU | HFNC, NIV | Not reported | – | Hospital discharge | 2–3 h sessions, over 3 days | Patient 1. SpO2 92% on FiO2 0.7 Patient 2. FiO2 0.8 |
Patient 1. SpO2 98% on FiO2 0.5 Patient 2. FiO2 0.4 |
0/2 (0) | Anxiety and discomfort in both patients |
| Ripoll-Gallardo (2020) | RC | 13 | PaO2:FiO2 < 150 | Requiring intubation, hemodyn-amic instability, multiorgan failure | Non-ICU Medical unit | Helmet CPAP | Encouraged as long as possible | PaO2:FiO2 | Hospital discharge | Mean 2.4 h (SD 0.87) | PaO2:FiO2 113 [108–121] | PaO2:FiO2 138 [126–178] | 9/13 (69) | No complications 7 deaths (54%) |
| Solverson (2020) | RC | 17 | Suspected or confirmed COVID-19, ICU consult, Hypoxemia (5 L to maintain SpO2 ≥ 90%), at least 1 prone session | – | ICU, non-ICU medical ward | NP, HFNC | Encouraged as long as possible | SpO2 Tolerability |
Hospital discharge | 35% < 1 h Median 75 min (range 30–480), Median 2 sessions (range 1–6) per day |
SpO2 91% (range 84–95) RR 28 (range 18–38) SpO2:FiO2 152 (range 97–233) |
SpO2 98% (range 92–100) RR 22 (range 15–33) SpO2:FiO2 165 (range 106–248) |
7/17 (41) | 47% pain/discomfort 6% delirium 2 deaths (12%) |
| Sztajnbok (2020) | RC | 2 | 43 Male 37 Male |
– | ICU | NRB | Encouraged as long as possible | – | ICU discharge | 8–10 h, single sessions | Patient 1. SpO2 100% on 10 L, RR 30 Patient 2. SpO2 94% on 10 L, RR 28 |
Patient 1. Decreased to 5 L Patient 2. SpO2 96% on 3 L, RR 22 |
0/2 (0) | Not reported |
| Xu (2020) | RC | 10 | COVID-19 confirmed, | Not reported | Target 16 h/d, target SpO2 > 90% | PaO2:FiO2 | Hospital discharge, mean LOS 17.7 d | 4–6 h sessions | PaO2:FiO2 89–228 | PaO2:FiO2 200–325** on day 3 of PP | 0/10 (0) | 0 deaths | ||
| Cascella (2020) | CR | 1 | 54 Male Received tocilizumab |
– | Not reported | NIV | 3 sessions per day | PaO2:FiO2 | Hospital discharge | Mean 90 min per session | PaO2:FiO2 150 | PaO2:FiO2 300 | 0/1 (0) | Not reported |
| Vibert (2020) | CR | 1 | 23 Female pregnant Hypoxemia |
– | ICU | HFNC and NIV | Not reported | – | Hospital discharge | 2 h periods | SpO2 89%, FiO2 0.6, 60 L/min | SpO2 96%, FiO2 0.6, 60 L/min | 0/1 (0) | No adverse patient or fetal events |
| Elkattawy (2020) | CR | 1 | 36 Male Hypoxemia | – | Non-ICU Medical unit | NP | Not reported | – | 1 day | >12 h per day | SpO2 94%, 4 L/min NP | SpO2 95%, room air | 0/1 (0) | Not reported |
| Slessarev (2020) | CR | 1 | 68 Male Hypoxemia | – | ICU | HFNC | Not reported | – | 4 days | 16–18 h per day | PaO2:FiO2 100** | PaO2:FiO2 250** | 0/1 (0) | 1 Nosebleed |
| Whittemore (2020) | CR | 1 | 60 Male Hypoxemia | – | ICU | NRB | Not reported | SpO2 | Hospital discharge | >18 h per day | SpO2 82% on 12 L NRB | SpO2 94% on 12 L NRB | 0/1 | Not reported |
* High flow nasal cannula success/failure, ** Range, estimated from a figure. Abbreviations: ARDS, acute respiratory distress syndrome; BNP, B-type natriuretic peptide; CPAP, continuous positive airway pressure; CR, case report; CT, computed tomography; DNR, do not resuscitate; ECMO, extracorporeal membrane oxygenation; ED, emergency department; FiO2, fraction of inhaled oxygen; GCS, Glasgow Coma Scale; HFNC, high-flow nasal cannula; HFPV, high-frequency percussive ventilation; HTN, hypertension; ICP, intracranial pressure; ICU, intensive care unit; IQR, interquartile range; LOS, length of stay; NIV, non-invasive ventilation; NP, nasal prongs; NRB, non-rebreather face mask; NYHA, New York Heart Association; PaO2, partial pressure of arterial oxygen; PC, prospective cohort; PP, prone position; RC, retrospective cohort; RA, room air; ROX, ROX index = SpO2/FiO2 x 1/respiratory rate; RR, respiratory rate; SBP, systolic blood pressure; SD, standard deviation; SpO2, oxygen saturation; US, ultrasound.