Table 1.
Baseline characteristics and outcomes according to allocated group
| APP (n = 216) |
Standard care (n = 214) |
RR (95% CI) |
P | |
|---|---|---|---|---|
| Characteristics | ||||
| Age—years | 58.6 ± 15.8 | 58.2 ± 15.8 | – | – |
| Female sex—no. (%) | 84 (38.9) | 88 (41.1) | – | – |
| Body mass indexa—kg/m2 | 30.3 ± 4.6 | 30.0 ± 3.8 | – | – |
| Days from symptoms onset to hospital admission | 8 (7–10) | 8 (7–9) | – | – |
| SpO2 at hospital admission—% | 79 (75–84) | 80 (75–85) | – | – |
| Hours from admission in hospital to study enrollment | 17 ± 9.3 | 16 ± 9.9 | – | – |
| Hours from HFNC to enrollment | 11.1 (4.8–20) | 9.4 (4.2–18.6) | – | – |
| At study enrollment | – | – | ||
| Respiratory rate—breaths/min | 25.0 ± 4.3 | 25.3 ± 4.2 | – | – |
| HFNC flow settings—L/min | 40 (40–40) | 40 (40–40) | – | – |
| FIO2 | 0.7 (0.6–1.0) | 0.7 (0.6–1.0) | – | – |
| SpO2/FIO2 | 134.7 ± 38.7 | 135.5 ± 37.9 | – | – |
| ROX index | 5.3 (3.7–7.1) | 5.5 (3.8–6.9) | – | – |
| Silent hypoxemia—no. (%) b | 58 (27) | 59 (27) | – | – |
| Lung ultrasound scorec | 18 (16–21) | 18 (15–22) | – | – |
| D-dimer—mg/dL | 1.2 (0.9–1.6) | 1.1 (0.8–1.7) | – | – |
| Coexisting illnessd | 153 (71) | 151 (71) | – | – |
| Use of glucocorticoids for treatment of COVID-19—no. (%) | 182 (84) | 184 (86) | – | – |
| Highest treating location | – | – | ||
| Intermediate care unit (patient-to-nurse-ratio 4:1)—no. (%) | 172 (80) | 162 (76) | – | – |
| Intensive care unit (patient-to-nurse-ratio 2:1)—no. (%) | 44 (20) | 52 (24) | – | – |
| Outcomes | ||||
| Intubation at day 28—no. (%) | 65/216 (30) | 92/214 (43) | 0.70 (0.54–0.90) | 0.006 |
| Mortality at day 28—no. (%) | ||||
| All patients | 71/216 (33) | 79/214 (37) | 0.89 (0.68–1.15) | 0.37 |
| Patients with IMV | 48/65 (74) | 59/92 (64) | 1.15 (0.93–1.42) | 0.18 |
| Treatment success at day 28 (alive without intubation)—no. (%) | 128/216 (59) | 102/214 (48) | 1.28 (1.04–1.57) | 0.01 |
| Adverse events | ||||
| Skin breakdown—no. (%) | 1 (0.5) | 3 (1.4) | – | – |
| Vomiting—no. (%) | 5 (2.3) | 10 (4.7) | – | – |
| Intravascular lines dislodgement—no. (%) | 14 (6.5) | 14 (6.5) | – | – |
| Back pain—no. (%) | 16 (7.4) | 13 (6.1) | – | – |
| Cardiac arrest related to position change | 0 | 0 | – | – |
| Median difference (95% CI) |
||||
|---|---|---|---|---|
| Days of HFNC in patients who had treatment success, median (IQR) | 8.7 (7.4–11.7) | 9.6 (7.5–12) | − 0.5 (− 1.4–0.2) | 0.21 |
| Days from study enrollment to intubation in patients with IMV, median (IQR) | 2.8 (1.9–4.1) | 2.2 (1.4–3.5) | 0.6 (0.1–1.0) | 0.02 |
| Days of IMV, median (IQR) | 9.4 (6.0–14.5) | 10.6 (7.8–14.3) | − 0.9 (− 2.6–0.8) | 0.29 |
| Hospital LOS, median (IQR) | 11 (9–14) | 13 (10–17) | − 1.5 (− 2–0) | 0.001 |
Plus–minus values are means ± SD; median with interquartile ranges is in parentheses. APP, awake prone positioning; HFNC, high-flow nasal cannula; SpO2, saturation of pulse oximetry; FIO2, fraction of inspired oxygen; ROX, SpO2/FIO2 /respiratory rate; CI, confidence interval; RR, relative risk; IMV, invasive mechanical ventilation; LOS, length of stay
aBody mass index is the weight in kilograms divided by the square of the height in meters
bSilent hypoxemia was defined as SpO2 < 90% at ambient air but no perception of symptoms of dyspnea or shortness of breath at hospital admission
cLung ultrasound with 12-lung regions technique, scores range from 0 to 36, with higher scores indicating lower lung aeration
dCoexisting illness included: chronic heart disease (known heart failure, coronary artery disease, or hypertension); chronic lung disease (obstructive or restrictive); chronic kidney disease (estimated glomerular filtration rate < 60 mL/min/1.73 m2 prior to hospital admission; severe liver disease (cirrhosis and/or portal hypertension with history of variceal bleeding, or liver disease with Child–Pugh score ≥ 10)