Table 1.
Demographic and baseline clinical parameters
| Variables* | All patients without AKI on admission (n = 2525) | New AKI in the ICU (n = 840) | No new AKI in the ICU (n = 1685) | p value |
|---|---|---|---|---|
| Demographics | ||||
| Age | 62 [48, 74] | 64 [51, 74] | 61 [43, 72] | 0.02 |
| Male sex | 1498 (59.3) | 519 (62.0) | 979 (58.0) | 0.06 |
| BMI | 24.2 [23, 28.1] | 25.4 [23.5, 30.0] | 24.2 [22.9, 29.0] | <0.001 |
| Body weight [kg] | 70 [63, 81] | 73 [65, 89] | 70 [60, 78] | < 0.001 |
| Parameters on the day of ICU admission | ||||
| Medical admission | 2012 (80) | 677 (81) | 1335 (79) | 0.69 |
| Elective surgical admission | 367 (15) | 113 (14) | 254 (16) | |
| Emergency surgical admission | 146 (5) | 50 (6) | 96 (6) | |
| Lowest MAP [mmHg] | 59 [53, 64] | 56 [51, 61] | 59 [55, 62] | 0.01 |
| SOFA score | 5 [3, 7] | 5 [3, 8] | 4 [3, 7] | <0.001 |
| CVP [mmHg] | 12 [8, 17] | 13 [9, 18] | 11 [7, 16] | <0.001 |
| Comorbidities | ||||
| Baseline serum creatinine [μmol/L) | 83 [63, 113] | 100 [75, 140] | 81 [60, 117] | <0.001 |
| Chronic kidney disease | 228 (9.0) | 111 (13.3) | 117 (6.9) | <0.001 |
| Chronic lung disease | 715 (28.3) | 246 (29.4) | 469 (27.8) | 0.40 |
| Chronic liver disease | 1645 (65.1) | 553 (66.1) | 1092 (67.1) | 0.51 |
| Cardiovascular disease | 545 (21.6) | 222 (26.5) | 343 (20.3) | <0.001 |
| Congestive heart failure | 200 (8.0) | 80 (9.6) | 120 (7.1) | 0.04 |
| Diabetes mellitus | 517 (20.5) | 197 (23.5) | 320 (19.0) | 0.01 |
| Cerebrovascular disease | 206 (8.2) | 73 (8.7) | 133 (7.9) | 0.49 |
| Cancer | 730 (28.9) | 218 (26.0) | 512 (30.3) | 0.03 |
| Primary diagnostic code for ICU admission | ||||
| Respiratory | 899 (35.6) | 298 (35.6) | 601 (35.6) | 1.00 |
| Neurologic | 179 (7.1) | 61 (7.3) | 118 (7.0) | 0.81 |
| Post-surgery | 429 (17.0) | 132 (15.8) | 297 (17.6) | 0.26 |
| Cardiovascular | 391 (15.4) | 145 (17.3) | 246 (14.6) | 0.08 |
| Gastrointestinal | 183 (7.2) | 59 (7.0) | 124 (7.3) | 0.81 |
| Urinary | 57 (2.3) | 14 (1.7) | 43 (2.5) | 0.20 |
| Sepsis | 210 (8.3) | 84 (10.0) | 126 (7.5) | 0.03 |
| Other | 339 (13.4) | 109 (13.0) | 230 (13.6) | 0.71 |
| Organ support from ICU admission to the day of AKI or day 3 | ||||
| Mechanical ventilation | 1444 (57.2) | 512 (61.2) | 932 (55.2) | 0.04 |
| ECMO | 130 (5.1) | 61 (7.3) | 69 (4.1) | 0.01 |
| IABP | 62 (2.5) | 31 (3.7) | 31 (1.8) | 0.01 |
| Surgery | 101 (4.0) | 35 (4.2) | 66 (3.9) | 0.75 |
| Epinephrine | 27 (1.1) | 13 (1.6) | 14 (0.8) | 0.10 |
| Norepinephrine | 1050 (41.6) | 427 (50.8) | 627 (37.1) | <0.001 |
| Vasopressin | 9 (0.4) | 5 (0.6) | 4 (0.2) | 0.17 |
| Time (in the first 7 days) spent on inotropic and vasoactive medications | ||||
| Number of days on at least 1 inotrope or vasopressor | 0 [0, 0] | 1 [0, 3] | 0 [0, 2] | < 0.001 |
| 0 days | 1405 (56) | 382 (45) | 1023 (61) | |
| 1–3 days | 725 (29) | 252 (30) | 473 (28) | |
| 4 or more days | 395 (16) | 206 (25) | 189 (11) | |
| Number of days on > 1 inotrope or vasopressor | 0 [0, 0] | 0 [0, 0] | 0 [0, 0] | < 0.001 |
| 0 days | 2324 (92) | 737 (88) | 1587 (94) | |
| 1–3 days | 178 (7) | 87 (10) | 91 (5) | |
| 4 or more days | 23 (1) | 16 (2) | 7 (0) | |
| Number of days on at least 1 vasopressor | 0 [0, 0] | 1 [0, 3] | 0 [0, 2] | < 0.001 |
| 0 days | 1428 (57) | 386 (46) | 1042 (62) | |
| 1–3 days | 718 (28) | 251 (30) | 467 (28) | |
| 4 or more days | 379 (15) | 203 (24) | 176 (11) | |
| Number of days on > 1 vasopressor | 0 [0, 0] | 0 [0, 0] | 0 [0, 0] | 0.001 |
| 0 days | 2502 (99) | 825 (98) | 1677 (99) | |
| 1–3 days | 23 (1) | 15 (2) | 8 (1) | |
| 4 or more days | 0 | 0 | 0 | |
| Potentially nephrotoxic exposures | ||||
| Vancomycin | 240 (9.5) | 82 (9.8) | 158 (9.4) | 0.72 |
| Diuretic | 1185 (46.9) | 381 (45.5) | 804 (47.6) | 0.33 |
| Aminoglycosides | 899 (35.6) | 291 (34.8) | 608 (36.0) | 0.57 |
| ACE-I/ARB | 180 (7.1) | 67 (8.0) | 113 (6.7) | 0.25 |
| Contrast | 252 (10.0) | 88 (10.5) | 164 (9.7) | 0.53 |
| Chemotherapy | 42 (1.7) | 11 (1.3) | 31 (1.8) | 0.88 |
| Antiretroviral drugs | 40 (1.6) | 11 (1.3) | 30 (1.8) | 0.41 |
| NSAID | 51 (2.0) | 8 (1.0) | 43 (2.5) | 0.01 |
| Fluid balance on the day of AKI/day 3 | ||||
| Cumulative FB in ml | 1389 (3455) | 2148.4 (3667.5) | 1002 (3276) | <0.001 |
| % of fluid balance in % BW | 1.66 [−0.7, 4.3] | 3.98 [1.2, 6.9] | 2.29 [−0.07, 5.14] | <0.001 |
| Outcomes | ||||
| ICU stay (days) | 13 [9, 21] | 9 [5, 17] | < 0.01 | |
| Hospital stay (days) | 31 [19, 56] | 22 [12, 43] | 0.94 | |
| ICU mortality (%) | 175 (20.9) | 94 (5.6) | < 0.01 | |
| Hospital mortality (%) | 273 (35.4) | 243 (15.4) | < 0.01 | |
ACE-I angiotensin converting enzyme inhibitor, ARB angiotensin receptor blocker, AKI acute kidney injury, BMI body mass index, BW body weight, CVP central venous pressure, ECMO extracorporeal membrane oxygenation, FB fluid balance, IABP intra-aortic balloon pump, ICU intensive care unit, MAP mean arterial pressure, NSAID non-steroidal anti-inflammatory drug, SD standard deviation, SOFA Sequential Organ Failure Assessment
*Results displayed as n (%), mean (SD) or median [interquartile range]