Table 1.
Patient characteristics including clinically relevant features used for prediction
| Parameter | Missing (%) | Values | Units |
|---|---|---|---|
| Number of prone events | 3619 | ||
| Number of patients | 1142 | ||
| Prone events per patient, median [Q1, Q3] | 2 [1, 4] | ||
| Age, median [Q1,Q3] | 0.0 | 66.0 [58.0,72.0] | Years |
| Gender, female, n (%) | 0.0 | 944 (26.1) | |
| BMI, median [Q1,Q3] | 0.0 | 27.2 [24.6,30.0] | |
| Comorbidities | |||
| Chronic dialysis, n (%) | 30.0 | 43 (1.7) | |
| Chronic renal insufficiency, n (%) | 30.0 | 256 (10.1) | |
| Cirrhosis, n (%) | 30.0 | 103 (4.1) | |
| COPD, n (%) | 30.0 | 349 (13.8) | |
| Diabetes, n (%) | 30.0 | 613 (24.2) | |
| Neoplasm, n (%) | 30.0 | 132 (5.2) | |
| Hematologic malignancy, n (%) | 30.0 | 193 (7.6) | |
| Immune insufficiency, n (%) | 30.0 | 356 (14.1) | |
| Respiratory insufficiency, n (%) | 30.0 | 196 (7.7) | |
| Cardiovascular insufficiency, n (%) | 30.0 | 131 (5.2) | |
| Clinical measurements, average | |||
| etCO2 2 h, mean (SD) | 14.6 | 41.3 (11.0) | mmHg |
| paCO2-etCO2 2 h, mean (SD) | 27.5 | 13.3 (10.9) | mmHg |
| FiO2 2 h, mean (SD) | 3.3 | 65.6 (17.6) | % |
| Peak airway pressure 2 h, mean (SD) | 10.3 | 27.2 (6.2) | cmH2O |
| Delta pressure 2 h, mean (SD) | 20.3 | 13.5 (5.4) | cmH2O |
| PEEP 2 h, mean (SD) | 8.1 | 12.2 (3.3) | cmH2O |
| Respiratory system compliance 2 h, mean (SD) | 10.2 | 43.6 (31.0) | ml/cmH2O |
| Tidal volume per kg 2 h, mean (SD) | 8.2 | 6.7 (1.5) | ml/kg |
| Respiratory rate 2 h, mean (SD) | 1.5 | 24.7 (5.5) | /min |
| Minute volume 2 h, mean (SD) | 8.3 | 11.0 (3.0) | ml/min |
| PaO2/FiO2 ratio 2 h, mean (SD) | 20.4 | 120.5 (45.4) | mmHg |
| Ventilatory ratio 2 h, mean (SD) | 12.6 | 2.3 (0.9) | |
| Mechanical power 2 h, mean (SD) | 12.5 | 32.9 (14.3) | J/min |
| Mean arterial blood pressure 2 h, mean (SD) | 3.2 | 78.7 (12.5) | mmHg |
| Heart rate 2 h, mean (SD) | 5.9 | 88.5 (19.6) | /min |
| CRP 2 h, mean (SD) | 21.0 | 199.2 (123.8) | mg/l |
| Leukocytes 2 h, mean (SD) | 6.5 | 11.5 (5.5) | 109/l |
| Thrombocytes 2 h, mean (SD) | 4.8 | 304.9 (135.1) | 109/l |
| d-dimer 2 h, mean (SD) | 57.7 | 3061.2 (2251.5) | ng/ml |
| Lactate arterial 2 h, mean (SD) | 44.0 | 1.3 (0.6) | mmol/l |
| pO2 arterial 2 h, mean (SD) | 19.5 | 69.7 (10.2) | mmHg |
| pCO2 arterial 2 h, mean (SD) | 6.8 | 53.9 (14.3) | mmHg |
| pH arterial 2 h, mean (SD) | 24.8 | 7.4 (0.1) | |
| Creatinine 2 h, mean (SD) | 6.0 | 115.8 (105.2) | µmol/l |
| Clinical measurements, slopes | |||
| Last FiO2 2 h slope, median [Q1,Q3] | 13.5 | 0.0 [− 5.0,2.5] | %/h |
| PaO2/FiO2 ratio 8 h slope, median [Q1,Q3] | 80.2 | 1.0 [− 1.7,3.7] | mmHg/h |
| Ventilatory ratio 8 h slope, median [Q1,Q3] | 47.6 | − 0.0 [− 0.0,0.0] | /h |
| Mechanical power 8 h slope, median [Q1,Q3] | 32.0 | 0.0 [− 0.6,0.6] | J/min/h |
| Outcomes | |||
| PaO2/FiO2 ratio 3 h last, median [Q1,Q3] | 18.3 | 111.6 [86.8,141.7] | |
| Ventilatory ratio 3 h last, median [Q1,Q3] | 32.2 | 2.2 [1.7,2.9] | |
| Mechanical power 3 h last, median [Q1,Q3] | 23.5 | 32.0 [20.9,44.7] | J/min |
| Respiratory system compliance 3 h last, median [q1, q3] | 9.8 | 32.8 [24.4,48.5] | ml/cmH2O |
| PaO2/FiO2 ratio difference, median [Q1, Q3] | 27.3 | 14.9 [− 5.3,40.5] | |
| Ventilatory ratio difference, median [Q1, Q3] | 37.4 | 0.0 [− 0.3,0.4] | |
| Mechanical power difference, median [Q1, Q3] | 26.7 | 0.2 [− 9.8,9.2] | J/min |
| Respiratory system compliance difference, median [Q1, Q3] | 12.9 | − 0.6 [− 5.8,3.6] | ml/cmH2O |
For clinical parameters, the mean of the past 2 h was aggregated per patient and slopes were calculated based on mean values in the hour before proning