Table 2.
Secondary outcomes for the study cohort
| Variable | Control group | Prone group | P value |
|---|---|---|---|
| Count | 39 | 36 | |
| Daily total prone time, hours | 3.4 [1.8–8.4] | 9.0 [4.4–10.6] | 0.014 |
| Total protocol duration, days | 4.9 [2.3–8.1] | 4.2 [1.7–5.7] | 0.33 |
| Daily prone time day 1–3, hours | 2.6 [0.3–8.1] | 8.5 [5.2–12.2] | 0.001 |
| 30-day mortality | 3 (8%) | 6 (17%) | 0.30 |
| VFDa, all patients, days | 30 [11–30] | 30 [12–30] | 0.69 |
| VFDa, intubated patients, days | 2 [1–10] | 7 [0–20] | 0.38 |
| Days free from HFNO/NIVb | 24 [22–26] | 26 [23–28] | 0.15 |
| Enrolment to IMV, days | 2 [1–6] | 2 [1–5] | 0.59 |
| Use of NIV | 27 (69%) | 21 (58%) | 0.33 |
| Enrolment to NIV, days | 0.25 [0.1–1.1] | 0.23 [0.05–1.2] | 0.63 |
| Admitted to ICU | 27 (69%) | 27 (75%) | 0.58 |
| ICU LOS, days | 11 [3–22] | 5 [4–13] | 0.25 |
| ICU-free daysc | 26 [8–30] | 25 [14–28] | 0.56 |
| Hospital LOS, days | 18 [11–30] | 16 [11–22] | 0.44 |
| Vasoactive drugs | 17 (44%) | 13 (37%) | 0.57 |
| Sedation by continuous infusiond | 14 (36%) | 16 (44%) | 0.45 |
| Renal replacement therapy | 1 (3%) | 1 (3%) | – |
| ECMO | 1 (3%) | 0 (0%) | – |
| WHO clinical progression scale day 7, (0–10) | 6 [6, 7] | 6 [5–7] | 0.35 |
| WHO clinical progression scale, day 30, (0–10) | 2 [2–6] | 2 [2–4] | 0.28 |
| Adverse events | |||
| Pressure sores | 9 (23%) | 2 (6%) | 0.032 |
| Vomiting during proning | 0 (0%) | 1 (3%) | - |
| Central or arterial line dislodgement | 0 (0%) | 0 (0%) | - |
| Cardiac arrest within 30 days | 1 (3%) | 2 (6%) | 0.51 |
| During proning | 0 (0%) | 0 (0%) | - |
Categorical parameters are presented as n (%), continuous variables as median (interquartile range [IQR]), VFD, Ventilator-Free Days; HFNO High-flow Nasal Oxygen; NIV, Noninvasive Ventilation; IMV, Invasive Mechanical Ventilation; ICU, Intensive Care Unit; LOS, Length of Stay; ECMO, Extracorporeal Membrane Oxygenation; WHO, World Health Organization
aVentilator-free days were calculated for intubated (Control n = 13, Prone n = 12) and all patients, respectively, and defined as days free from invasive mechanical ventilation from enrollment until day 30. Patients who died were registered as 0 VFD
bPatients who were not intubated. Calculated from enrollment until day 30. Control n = 26, Prone n = 24
cDays when patients were not in the ICU. Patients who died were registered as 0 ICU-free days
dNon-intubated patients during protocol