Table 1.
Patient characteristics and ventilation variables at enrolment
| Age, median (IQR) | 54 (49, 60) |
| Female sex, n (%) | 10 (33) |
| APACHE II, median (IQR) | 21 (18, 24) |
| SOFA, median (IQR) | 11 (10, 12) |
| AHRF severity, median (IQR) | |
| Moderate: PaO2:FiO2 100-200 mm Hg | 7 (23) |
| Severe: PaO2:FiO2 <100 mm Hg | 23 (77) |
| Comorbidities, n (%) | |
| COPD | 5 (17) |
| Asthma | 3 (10) |
| Diabetes | 8 (27) |
| Chronic kidney disease | 1 (3) |
| Interstitial lung disease | 7 (23) |
| Etiology of respiratory failure | |
| Bacterial pneumonia | 13 (43) |
| Fungal pneumonia | 1 (3) |
| Viral pneumonia (non-COVID-19) | 2 (7) |
| COVID-19 pneumonia | 14 (47) |
| SAS, median (IQR) | 1 (1,2) |
| PaO2:FiO2 (mm Hg)*, median (IQR) | 109 (79, 167) |
| Ventilatory ratio†, median (IQR) | 2 (1.6, 2.7) |
| Mode of ventilation, n (%) | |
| Assist-control volume ventilation | 21 (70) |
| Assist-control pressure ventilation | 9 (30) |
| VT/PBW (ml/kg), median (IQR) | 6 (5, 8) |
| PEEP (cm H2O), median (IQR) | 10 (9, 14) |
| Driving pressure (cm H2O), median (IQR) | 17 (12, 19) |
| Respiratory system compliance (ml/cm H2O), median (IQR) | 23 (16, 37) |
| Normalized respiratory system elastance (cm H2O/ml/PBW), median (IQR) | 2.6 (1.9, 5) |
| ECLS blood flow, (L/min) median (IQR) | 5 (4, 5) |
| Sweep gas flow (L/min), median (IQR) | 5 (4, 5) |
IQR interquartile range, COPD chronic obstructive pulmonary disease, SOFA sequential organ failure assessment, SAS sedation-agitation score, VT tidal volume, PEEP positive end-expiratory pressure, PBW predicted body weight, ECLS extracorporeal life support
*Represents only patients not receiving VV-ECMO (n = 14). Values of PaO2:FiO2 may not be representative of lung function in patients receiving VV-ECMO at enrolment
†Represents only patients not receiving VV-ECMO (n = 14). Values of VR may not be representative of lung function in patients receiving VV-ECMO at enrolment