Table 2 Vitals, respiratory parameters, and outcomes (n = 111)
|  | Total HFNC (n = 111) | HFNC success (n = 72) | HFNC failure (n = 39) | P value |
|---|---|---|---|---|
Vital signs before the initiation of HFNC | ||||
 GCS | 15 (13–15) | 15 (14–15) | 15 (12–15) | 0.223 |
 Heart rate | 103.0 (87.0–114.0) | 103.0 (84.5–115.8) | 105.0 (92.0–113.0) | 0.834 |
 Respiratory rate | 26.0 (21.0–30.0) | 25.0 (21.0–28.8) | 27.0 (21.0–33.0) | 0.238 |
 SpO2, % | 95.0 (91.0–97.0) | 94.5 (91.0–97.0) | 95.0 (91.0–97.0) | 0.804 |
Arterial blood gas analysis before the initiation of HFNC | ||||
 pH | 7.44 (7.38–7.47) | 7.45 (7.40–7.47) | 7.41 (7.37–7.47) | 0.558 |
 PaO2, mmHg | 68.7 (59.0–80.0) | 69.5 (58.7–81.8) | 65.0 (59.0–74.5) | 0.261 |
 PF ratio | 162.5 (112.0–228.0) | 179.0 (126.5–268.3) | 140.0 (100.0–176.0) | 0.128 |
 PaCO2, mmHg | 32.6 (28.0–38.0) | 32.0 (28.4–38.0) | 33.0 (28.0–38.0) | 0.640 |
 SaO2, % | 94.0 (92.0–97.0) | 95.0 (92.0–97.0) | 93.0 (91.0–96.0) | 0.261 |
 Bicarbonate, mmol/L | 21.9 (18.7–25.4) | 21.9 (18.9–25.2) | 22.4 (18.7–26.0) | 0.944 |
HFNC settings and duration | ||||
 Initial HFNC flow | 60.0 (60.0–60.0) | 60.0 (60.0–60.0) | 60.0 (60.0–60.0) | 1.000 |
 Initial FIO2 set on HFNC | 40.0 (33.0–80.0) | 40.0 (35.0–50.0) | 50.0 (40.0–60.0) | 0.123 |
 Duration of HFNC (hours) | 18.2 (10.3–34.5) | 26.1 (15.6–41.9) | 9.6 (5.1–14.8) |  < 0.001** |
Mortality outcome | ||||
 Hospital Mortality | 18 (16.2%) | 7 (9.7%) | 11 (28.2%) |  < 0.001** |
 ICU Mortality | 7 (6.3%) | 1 (1.4%) | 6 (15.4%) | 0.004** |