Table 1.
Baseline characteristics of patients (n=124)
| n (%) | |
|---|---|
| Age | 65 (55-78) |
| Body weight (kg) | 54.2 (44.28-59.95) |
| Height (cm)¥ | 157.86 (10.03) |
| Physical parameters upon ICU admission | |
| O2 flow (LPM) | 8 (6-15) |
| Respiratory rate | 26 (22-32) |
| SpO2 | 94 (91-97) |
| Temp (°C) | 37.6 (36.93-38.3) |
| Heart rate¥ | 107.54 (23.13) |
| MAP (mmHg) | 85 (71.25-97.75) |
| Physical parameters before HFNC | |
| FiO2 1 h before HFNC (LPM) | 8 (6-11) |
| Respiratory rate before HFNC | 28 (23.75-32) |
| SpO2 before HFNC | 92 (90-94) |
| GCS before HFNC | 15 (15-15) |
| Flow of HFNC at commencement (LPM) | 40 (40-40) |
| Physical parameters 1 h after HFNC | |
| Flow rate (LPM) | 40 (40-40) |
| FiO2 | 0.5 (0.45-0.6) |
| GCS | 15 (14-15) |
| Heart rate | 104.28 (21.61) |
| Respiratory rate | 26 (23-32) |
| SpO2 | 92 (90-94) |
| Physical parameters 12 h after HFNC | |
| Heart rate¥ | 96.2 (21.4) |
| Respiratory rate | 27.25 (23-31) |
| ROX index | |
| ROX 1 h | 6.45 (4.95-8.24) |
| ROX 12 h | 7.14 (5.61-9.20) |
| Blood parameters on day of HFNC | |
| pH | 7.46 (7.42-7.49) |
| PaCO2 (kPa) | 4.37 (3.86-5.18) |
| PaO2 (kPa) | 9.93 (8.66-11.6) |
| HCO3 (mmol/L) | 22.4 (19.8-26.0) |
| Hemoglobin (g/dL) | 10.2 (9.1-11.9) |
| White cell count ×109/L | 12.2 (8.31-17.64) |
| Platelet×109/L | 209 (108-288) |
| Sodium (mmol/L) | 137 (133-140) |
| Potassium (mmol/L) | 3.8 (3.5-4.1) |
| Urea (mmol/L) | 6.9 (4.8-11) |
| Creatinine (µmol/L) | 69 (55-127) |
| Bilirubin (mmol/L) | 14 (9.23-22) |
| ICU stay days | 6.6 (3.99-14.88) |
| APACHE IV score | 68.5 (56.25-89.75) |
| Time from admission to HFNC (h) | 21.36 (5.04-54.72) |
| HFNC duration (h) | 27.41 (11.61-64.48) |
| Categorical baseline characteristics | |
| Sex¶ | |
| Male | 82 (66.7) |
| Cause of respiratory failure¶ | |
| Pneumonia | 96 (77.4) |
| Cancer or carcinomatosis | 4 (3.2) |
| Interstitial lung disease | 6 (4.8) |
| Fluid overload/CHF | 12 (9.7) |
| ARDS | 2 (1.6) |
| Hemoptysis | 1 (0.8) |
| Pulmonary embolism | 1 (0.8) |
| Pleural effusion | 1 (0.8) |
| Atelectasis | 1 (0.8) |
| Cause of pneumonia¶ | |
| Nonspecific, bacterial | 85 (88.5) |
| Influenza | 3 (3.1) |
| CMV | 1 (1) |
| Aspiration | 3 (3.1) |
| PCP | 1 (1) |
| Adenovirus | 1 (1) |
| Other viruses | 2 (2.1) |
| Modality of O2 delivery before HFNC¶ | |
| Nasal cannula | 35 (28.2) |
| Nonrebreathing mask | 72 (58.1) |
| Hudson mask | 1 (0.8) |
| Optiflow | 2 (1.6) |
| NIV | 14 (11.3) |
| Choice of vasopressor 1 h before HFNC¶ | |
| None | 109 (87.9) |
| Noradrenaline | 14 (11.3) |
| Dopamine | 1 (0.8) |
| Choice of vasopressor 12 h after HFNC¶ | |
| None | 112 (90.3) |
| Noradrenaline | 12 (9.7) |
| Dopamine | 0 (0) |
| Modality of O2 delivery after HFNC¶ | |
| Nasal cannula | 48 (38.7) |
| NRM | 5 (4) |
| Noninvasive ventilation | 21 (16.9) |
| Mechanical ventilation | 43 (34.7) |
| Death | 2 (1.6) |
| ECMO | 1 (0.8) |
| Direct high-flow nasal cannula to general ward | 4 (3.2) |
| Success¶ | 55 (44.35) |
| Failure¶ | 69 (55.6) |
| Direct to mechanical ventilation | 43 (34.7) |
| Direct to NIV (in which 6 patients later escalate to mechanical ventilation) | 21 (16.9) |
| Direct to ECMO | 1 (0.8) |
| Death during HFNC | 2 (1.6) |
| HFNC to Nasal cannula or NRM to mechanical ventilation | 2 (0.8) |
| Mortality¶ | 31 (25) |
Results shown as median (IQR) unless otherwise specified, ¶n (%) ¥Mean±SD. FiO2: Fraction of inspired oxygen, SpO2: Peripheral capillary oxygen saturation, MAP: Mean arterial pressure, HFNC: High-flow nasal cannula, GCS Glasgow Coma Scale, CHF: Congestive heart failure, ROX: Ratio of pulse oximetry/fraction of inspired oxygen to respiratory rate, APACHE: Acute Physiology and Chronic Health Evaluation, AKI: Acute kidney injury, ARDS: Acute respiratory distress syndrome, CMV: Cytomegalovirus, PCP: Pneumocystis pneumonia, NRM: Nonrebreathing mask, NIV: Noninvasive ventilation, ECMO: Extracorporeal membrane oxygenation, IQR: Interquartile range, ICU: Intensive care unit, SD: Standard deviation