Table 1 Characteristics, illness severity profile and outcomes of patients with COVID-19, acute respiratory distress syndrome (ARDS) stratified by the presence of acute kidney injury (AKI)
| Â | n | No AKIa | Stage 1 AKIa | Stage 2 AKIa | Stage 3 AKIa | p valueb |
|---|---|---|---|---|---|---|
Acute kidney injury (AKI) | 1699 | 1344 (79.1%) | 110 (6.5%) | 94 (5.5%) | 151 (8.9%) | Â |
Age (years) | 1697 | 56 (15) | 62 (15) | 61 (14) | 58 (15) | < 0.001 |
Sex (male) | 1696 | 889 (66%) | 71 (65%) | 58 (62%) | 94 (63%) | 0.7 |
Body mass index (kg/m2) | 1366 | 30 (8) | 30 (8) | 32 (10) | 31 (9) | 0.3 |
Region | 1699 | Â | Â | Â | Â | 0.001 |
 Europe high income |  | 269 (20%) | 15 (14%) | 14 (15%) | 15 (9.9%) |  |
 Rest of the world high income |  | 818 (61%) | 83 (75%) | 67 (71%) | 100 (66%) |  |
 Rest of the world middle income |  | 257 (19%) | 12 (11%) | 13 (14%) | 36 (24%) |  |
Comorbidities | ||||||
Diabetes | 1652 | 388 (30%) | 34 (33%) | 32 (35%) | 55 (38%) | 0.2 |
Hypertension | 1697 | 585 (44%) | 72 (65%) | 51 (54%) | 91 (60%) | < 0.001 |
Malignant neoplasm | 1696 | 52 (3.9%) | 3 (2.8%) | 4 (4.3%) | 7 (4.6%) | 0.9 |
Severe liver disease | 1698 | 14 (1.0%) | 2 (1.8%) | 1 (1.1%) | 1 (0.7%) | 0.7 |
Chronic cardiac disease | 1693 | 158 (12%) | 29 (26%) | 15 (16%) | 27 (18%) | < 0.001 |
Illness severity | ||||||
ARDS severity category | 1384 |  |  |  |  | < 0.001 |
 Mild |  | 46 (4%) | 2 (2%) | 3 (4%) | 4 (3%) |  |
 Moderate |  | 202 (19%) | 21 (20%) | 13 (16%) | 23 (17%) |  |
 Severe |  | 818 (77%) | 81 (78%) | 65 (80%) | 106 (80%) |  |
Sequential organ failure assessment (cardiovascular) | 1552 | Â | Â | Â | Â | Â |
 0 |  | 1033 (84%) | 66 (65%) | 59 (69%) | 103 (76%) | < 0.001 |
 1 |  | 185 (15%) | 36 (35%) | 26 (30%) | 30 (22%) |  |
 2 |  | 4 (0.3%) | 0 (0%) | 0 (0%) | 0 (0%) |  |
 3 |  | 4 (0.3%) | 0 (0%) | 0 (0%) | 1 (0.7%) |  |
 4 |  | 3 (0.2%) | 0 (0%) | 1 (1.2%) | 1 (0.7%) |  |
Arterial pH | 1453 | 7.34 (0.12) | 7.26 (0.14) | 7.22 (0.12) | 7.23 (0.14) | < 0.001 |
Management (worst parameters first 48Â hrs) | ||||||
Positive end-expiratory pressure (PEEP, cmH2O) | 1316 | 11.6 (3.4) | 12.0 (3.7) | 12.1 (4.0) | 11.4 (4.2) | 0.6 |
Need for extracorporeal membrane oxygenation (ECMO) | 1550 | 99 (8%) | 13 (12%) | 17 (18%) | 18 (12%) | 0.006 |
Lowest tidal volume (mL) | 957 | 398 (121) | 408 (125) | 367 (131) | 397 (140) | 0.5 |
Highest respiratory rate (breaths per minute) | 1290 | 26 (8) | 27 (8) | 27 (9) | 28 (8) | < 0.001 |
Treatments received | ||||||
Heparin | 886 | 636 (89%) | 52 (88%) | 40 (91%) | 59 (86%) | 0.8 |
Corticosteroids | 1658 | 976 (75%) | 69 (63%) | 61 (65%) | 98 (66%) | 0.003 |
Antibiotics | 1666 | 1267 (96%) | 107 (99%) | 89 (95%) | 138 (93%) | 0.084 |
Outcomes | ||||||
Length of stay on invasive mechanical ventilation (days) All | 1654 | 12 (19) | 12 (16) | 10 (16) | 7 (16) | < 0.001 |
Survivors | 752 | 13 (20) | 16 (24) | 23 (30) | 18 (17) | 0.061 |
Length of stay in ICU (days) All | 1528 | 22 (41) | 10 (74) | 20 (19) | 17 (17) | 0.003 |
Survivors | 760 | 28 (45) | 8 (101) | 34 (19) | 30 (21) | 0.028 |
Length of stay in hospital All | 1490 | 33 (40) | 26 (33) | 28 (26) | 24 (24) | < 0.001 |
Survivors | 735 | 43 (46) | 39 (22) | 54 (27) | 46 (27) | 0.018 |
28-day mortality | 1699 | 544 (40%) | 55 (50%) | 62 (66%) | 104 (69%) | < 0.001 |
90-day mortality | 1699 | 660 (49%) | 64 (58%) | 70 (74%) | 105 (70%) | < 0.001 |