Table 1 Characteristics of patients at randomization
Characteristic | All patients (n = 788) | Modified high-flow nasal cannula oxygen group therapy (n = 392) | Conventional oxygen therapy group (n = 396) |
|---|---|---|---|
Age (years) | 58.5 (49.0–66.0) | 58.0 (50.0–66.0) | 59.0 (48.0–66.0) |
Male, no. (%) | 426 (54.1) | 204 (52.4) | 222 (56.1) |
Body mass index (kg/m2) | 23.7 (21.1–26.0) | 23.7 (21.3–26.0) | 23.6 (21.0–26.1) |
Current smoker, no. (%) | 173 (22.0) | 85 (21.7) | 88 (22.2) |
Pack-years no | 30.0 (15.0–45.0) | 30.0 (13.5–50.0) | 30.0 (15.0–40.0) |
Indication for bronchoscopy, no. (%) | Â | Â | Â |
 Hemoptysis | 87 (11.0) | 40 (10.2) | 47 (11.9) |
 Unexplained chronic cough | 39 (4.9) | 22 (5.6) | 17 (4.3) |
 Non-resolving pneumonia | 165 (20.9) | 78 (19.9) | 87 (22.0) |
 Pneumonia in immunocompromised host | 71 (9.0) | 41 (10.5) | 30 (7.6) |
 Interstitial lung disease | 158 (20.1) | 85 (21.7) | 73 (18.4) |
 Suspected lung cancer | 260 (33.0) | 123 (31.4) | 137 (34.6) |
 Foreign body aspiration | 8 (1.0) | 3 (0.8) | 5 (1.3) |
Vital signs | Â | Â | Â |
 Temperature, °C | 36.6 ± 0.51 | 36.6 ± 0.49 | 36.6 ± 0.53 |
 Respiratory rate (beats/min) | 17 ± 4 | 17 ± 5 | 18 ± 4 |
 Heart rate (beats/min) | 84 ± 15 | 84 ± 15 | 83 ± 15 |
 Mean arterial pressure (mmHg) | 93 ± 17 | 93 ± 20 | 94 ± 13 |
Arterial blood gas (room air) | Â | Â | Â |
 pH | 7.42 (7.40–7.44) | 7.42 (7.40–7.44) | 7.42 (7.39–7.44) |
 PaO2 (mmHg) | 79.0 (71.0–88.0) | 80.0 (70.0–89.0) | 79.0 (71.0–88.0) |
 PaCO2 (mmHg) | 40.0 (37.0–43.0) | 40.0 (37.0–43.0) | 40.0 (37.0–43.0) |
 HCO3− (mmol/L) | 24.4 (21.8–27.2) | 24.6 (22.2–26.9) | 23.8 (21.4–27.9) |
 SaO2 (%) | 96.0 (94.0–97.0) | 96.0 (94.0–97.0) | 96.0 (94.0–97.0) |
Baseline spirometry | Â | Â | Â |
 FVC (L) | 3.08 ± 0.95 | 3.13 ± 0.91 | 3.03 ± 0.98 |
 FEV1 (L) | 2.32 ± 0.78 | 2.36 ± 0.74 | 2.28 ± 0.82 |
 FEV1 (% predicted) | 82.7 ± 12.7 | 81.3 ± 13.3 | 83.9 ± 12.2 |
 FEV1/FVC (%) | 73.4 ± 12.8 | 73.7 ± 12.0 | 73.2 ± 13.2 |
 DLco (% predicted) | 78.1 ± 9.9 | 77.9 ± 9.5 | 78.4 ± 10.3 |
Laboratory parameters | Â | Â | Â |
 White blood cell (× 109/L) | 6.59 (5.23–8.27) | 6.34 (5.07–8.25) | 6.79 (5.34–8.33) |
 Platelet count (× 109/L) | 237 (194–293) | 232 (192–288) | 242 (196–300) |
 Prothrombin time (s) | 11.2 (9.9–12.6) | 11.1 (10.0–12.4) | 11.3 (9.8–12.7) |
 Fibrinogen (mg/dL) | 285.1 ± 104.1 | 283.6 ± 104.6 | 286.6 ± 103.7 |
 C-reactive protein (mg/dL) | 0.8 (0.5–1.2) | 0.8 (0.5–1.1) | 0.8 (0.5–1.2) |
 Procalcitonin (pg/ml) | 0.10 (0.08–0.12) | 0.10 (0.08–0.11) | 0.10 (0.08–0.12) |