Table 1.
Baseline patient characteristics
| All participants (n=553) | |||
|---|---|---|---|
| Age, years | 67·0 (59·0–73·0) | ||
| Gender | |||
| Men | 417/553 (75%) | ||
| Women | 136/553 (25%) | ||
| Body-mass index, kg/m2 | 27·7 (25·1–30·4) | ||
| Transferred from another intensive care unit under invasive ventilation | 104/553 (19%) | ||
| Duration of invasive ventilation before admission, days | 0·0 (0·0–2·0) | ||
| Use of non-invasive ventilation | 51/489 (10%) | ||
| Duration of non-invasive ventilation, h | 8·0 (3·8–13·9) | ||
| Chest CT scan performed | 146/553 (26%) | ||
| Lung parenchyma affected | |||
| 0% | 8/146 (5%) | ||
| 25% | 46/146 (32%) | ||
| 50% | 39/146 (27%) | ||
| 75% | 46/146 (32%) | ||
| 100% | 7/146 (5%) | ||
| Chest x-ray performed | 321/553 (87%) | ||
| Number of quadrants affected* | |||
| 1 | 16/318 (5%) | ||
| 2 | 69/318 (22%) | ||
| 3 | 97/318 (31%) | ||
| 4 | 136/318 (43%) | ||
| Pneumothorax† | 1/129 (1%) | ||
| Severity of illness | |||
| SAPS II (n=198) | 38·0 (31·0–45·0) | ||
| APACHE II (n=146) | 16·0 (12·0–20·0) | ||
| APACHE IV (n=271) | 57·0 (45·0–70·5) | ||
| SOFA (n=253) | 8·0 (6·0–11·0) | ||
| Severity of acute respiratory distress syndrome‡ | |||
| Mild | 135/541 (25%) | ||
| Moderate | 360/541 (67%) | ||
| Severe | 46/541 (9%) | ||
| Co-existing disorders | |||
| Hypertension | 200/553 (36%) | ||
| Heart failure | 25/553 (5%) | ||
| Diabetes | 111/553 (20%) | ||
| Chronic kidney disease | 23/553 (4%) | ||
| Baseline creatinine, μmol/L§ | 79·0 (64·0–98·0) | ||
| Liver cirrhosis | 2/553 (<1%) | ||
| Chronic obstructive pulmonary disease | 52/553 (9%) | ||
| Active haematological neoplasia | 8/553 (1%) | ||
| Active solid neoplasia | 13/553 (2%) | ||
| Neuromuscular disease | 8/553 (1%) | ||
| Immunosuppression | 12/553 (2%) | ||
| Previous medication | |||
| Systemic steroids | 27/553 (5%) | ||
| Inhalation steroids | 67/553 (12%) | ||
| Angiotensin-converting enzyme inhibitor | 106/553 (19%) | ||
| Angiotensin II receptor blocker | 64/553 (12%) | ||
| β blockers | 113/553 (20%) | ||
| Insulin | 31/553 (6%) | ||
| Metformin | 74/553 (13%) | ||
| Statins | 174/553 (31%) | ||
| Calcium channel blockers | 104/553 (19%) | ||
Data are median (IQR) or n/N (%). APACHE=Acute Physiology and Chronic Health Evaluation. SAPS=Simplified Acute Physiology Score. SOFA=Sequential Organ Failure Assessment.
*
321 patients had a chest x-ray, but three are not included here because original images could not be accessed for analysis.
†
Data was available for 129 patients.
‡
Baseline ratio of partial pressure of arterial oxygen to fractional concentration of oxygen in inspired air was missing in 12 patients.
§
Most recent measurement in the 24 h before intubation or at ICU admission under invasive ventilation.