Table 1.
Comparison of baseline characteristics and outcomes between patients treated by noninvasive positive pressure ventilation (NIV) or high-flow nasal cannula (HFNC) oxygen therapy alone
| NIV (n = 55) | HFNC (n = 60) | p value | |
|---|---|---|---|
| Age (years) | 58 (44–66) | 62 (50–70) | 0.06 |
| Gender (male) | 42 (76 %) | 35 (58 %) | 0.048 |
| Knaus chronic health status score | 0.46 | ||
| A | 15 (27 %) | 19 (32 %) | |
| B | 17 (31 %) | 22 (37 %) | |
| C | 21 (38 %) | 15 (25 %) | |
| D | 2 (3.6 %) | 4 (6.7 %) | |
| Mac Cabe classification | 0.20 | ||
| 1 | 20 (36 %) | 19 (32 %) | |
| 2 | 19 (35 %) | 30 (50 %) | |
| 3 | 16 (29 %) | 11 (18 %) | |
| SAPS II at ICU admission (points) | 42 ± 11 | 46 ± 13 | 0.10 |
| Modified SOFA score at inclusion (points) | 3 (1–6) | 4 (1–6) | 0.28 |
| Type of immunosuppression | 0.30 | ||
| Hematologic cancer or neutropenia | 33 (60 %) | 31 (52 %) | |
| Solid cancer | 11 (20 %) | 8 (13 %) | |
| Drug-induced immunosuppression | 10 (18 %) | 20 (33 %) | |
| Acquired immune deficiency syndrome | 1 (2 %) | 1 (2 %) | |
| Cause of respiratory failure | 0.38 | ||
| Documented infection | 24 (44 %) | 31 (52 %) | |
| Cardiogenic pulmonary edema | 5 (9 %) | 5 (8 %) | |
| Specific | 13 (24 %) | 6 (10 %) | |
| Other identified causes | 7 (13 %) | 11 (18 %) | |
| Not identified cause | 6 (11 %) | 7 (12 %) | |
| Clinical and biological parameters at inclusion | |||
| Heart rate (beats/min) | 111 ± 22 | 113 ± 23 | 0.71 |
| Systolic blood pressure (mmHg) | 130 (113–150) | 119 (110–147) | 0.28 |
| Respiratory rate (breaths/min) | 30 (26–33) | 29 (26–32) | 0.75 |
| SpO2 (%) | 94 (91–98) | 96 (94–99) | 0.02 |
| Body temperature (°C) | 37.8 ± 1.1 | 38.0 ± 1.1 | 0.47 |
| Bilateral lung infiltrates on chest X-ray | 46 (84 %) | 50 (83 %) | >0.99 |
| Arterial pH | 7.44 (7.40–7.47) | 7.46 (7.43–7.50) | 0.02 |
| PaO2-to-FiO2 ratio (mmHg) | 141 (111–177) | 149 (107–204) | 0.19 |
| PaO2-to-FiO2 ratio ≤ 200 mmHg | 47 (85 %) | 44 (73 %) | 0.17 |
| PaCO2 (mmHg) | 37 (32–45) | 32 (29–38) | <0.0001 |
| PaCO2 > 45 mmHg | 12 (22 %) | 2 (3 %) | 0.003 |
| Sodium bicarbonate (mmol/l) | 25 (22–28) | 21 (24–26) | 0.04 |
| Vasopressors within 24 h after ICU admission | 9 (16 %) | 14 (23 %) | 0.35 |
| Time from admission to ventilatory support initiation (h) | 1 (0–1) | 1 (0–1) | 0.62 |
| Need for immunosuppressive drug during ICU stay | 13 (24 %) | 15 (25 %) | >0.99 |
| Admission before 2011 | 26 (47 %) | 12 (20 %) | <0.0001 |
| Primary outcome | |||
| 28-day mortality | 22 (40 %) | 12 (20 %) | 0.02 |
| Secondary outcomes | |||
| Intubation | 30 (55 %) | 21 (35 %) | 0.04 |
| Time from admission to intubation (h) | 28 (18–49) | 35 (9–49) | 0.99 |
| Length of invasive mechanical ventilation (days) | 8 (4–11) | 7 (4–12) | 0.63 |
| Length of ICU stay (days) | 8 (5–13) | 7 (4–9) | 0.08 |
| In-ICU mortality | 20 (36 %) | 9 (15 %) | 0.01 |
Nominal variables are given as number (%), and continuous data are given as median (25th–75th percentile) or mean ± standard deviation (SD) according to their distribution using the Kolmogorov–Smirnov test
SAPS Simplified Acute Physiology Score, SOFA Sequential Organ Failure Assessment