Patients’ baseline demographic and clinical characteristics, and clinical and laboratory data at RICU admission
| All cases (n=28) | Success group (n=19) | Failure group (n=9) | P value | |
| Clinical and demographic features | ||||
| Age (years), median (min–max) | 69 (42–87) | 67 (42–84) | 80 (64–87) | 0.0543 |
| Gender (males/females) | 21/7 | 13/6 | 8/1 | 0.2513 |
| No of smokers | 6 (21.4%) | 3 (15.7%) | 3 (33.3%) | 0.2995 |
| No of patients with comorbidities | 20 (71.4%) | 13 (68.4%) | 7 (77.8%) | 0.5286 |
| No of comorbidities per patient, median (min–max) | 1 (0–4) | 1 (0–4) | 2 (0–4) | 0.3922 |
| Clinical and laboratory data at RICU admission | ||||
| Respiratory rate (breaths/min), median (min–max) | 26 (12–40) | 24 (12–40) | 26 (15–36) | 0.6950 |
| Heart rate (beats/min), median (min–max) | 77 (59–105) | 77 (59–89) | 77.5 (62–150) | 0.6362 |
| No of patients with fever (temperature >38°C) | 11 (21.4%) | 6 (31.6%) | 5 (55.6%) | 0.2770 |
| No of patients with leucopenia (WBC <4400×106/L) | 3 (10.7%) | 3 (15.7%) | 0 (0%) | 0.2154 |
| PaO2 (mm Hg), median (min–max) | 57 (36.2–67.1) | 58.3 (36.2–67.1) | 55.5 (39.9–61) | 0.1224 |
| PaCO2 (mm Hg), median (min–max) | 32 (27–45) | 31.9 (28–45) | 32.9 (27–39) | 0.9115 |
| Arterial pH, median (min–max) | 7.48 (7.39–7.54) | 7.49 (7.39–7.52) | 7.47 (7.40–7.54) | 0.9357 |
| SaO2 (%), median (min–max) | 92 (79–97) | 93 (79–97) | 90 (79–94) | 0.0293 |
| FiO2, median (min–max) | 0.6 (0.4–1.0) | 0.6 (0.4–1.0) | 0.8 (0.6–1.0) | 0.0085 |
| PaO2/FiO2 (mm Hg), median (min–max) | 108 (52–296) | 126 (52–296) | 76 (53–190) | 0.0194 |
| No of patients with PaO2/FiO2 ≤100 | 13 (46.4%) | 6 (31.6%) | 7 (77.8%) | 0.0246 |
| D-dimer (ng/mL), median (min–max) | 444 (159–259) | 327 (168–759) | 727 (159–259) | 0.1985 |
| Serum CRP (μg/mL), median (min–max) | 110 (29–270) | 110 (29–180) | 130.0 (110–270) | 0.0277 |
| Ferritin (ng/mL), median (min–max) | 1465.5 (156–5292) | 1399.5 (156–5292) | 1465.5 (877–1999) | 1.000 |
| SOFA score, median (min–max) | 2 (2–4) | 2 (2–4) | 3 (2–3) | 0.4610 |
P values refer to differences between HFNC success and HFNC failure groups.
CRP, C reactive protein; HFNC, high-flow nasal cannula; PaO2/FiO2, arterial oxygen tension to inspired oxygen fraction ratio; SaO2, arterial oxygen saturation; SOFA, sequential organ failure assessment.