Table 1.
Patient characteristics at baseline
| Characteristic | All Patients, n=3099 | No AKI-RRT, n=2462 | AKI-RRT, n=637 | P Value |
|---|---|---|---|---|
| Demographics | ||||
| Age, yr, median (IQR) | 62 (51–71) | 62 (51–72) | 62 (52–69) | 0.15 |
| Men, no. (%) | 2003 (64.6) | 1546 (63.8) | 457 (71.7) | <0.001 |
| Race, no. (%) | <0.001 | |||
| White | 1154 (37.2) | 981 (39.8) | 173 (27.2) | |
| Black | 952 (30.7) | 672 (27.3) | 280 (44.0) | |
| Asian | 190 (6.1) | 163 (6.6) | 27 (4.2) | |
| Other/unknown | 803 (25.9) | 646 (26.2) | 157 (24.7) | |
| Hispanic, no. (%) | 1045 (33.7) | 853 (34.6) | 192 (30.1) | |
| Body mass index, median (IQR) | 30.4 (26.6–36.1) | 29.8 (26.1–35.2) | 32.6 (28.2–39.3) | <0.001 |
| Coexisting conditions, no. (%)a | ||||
| Diabetes mellitus, insulin dependent | 419 (13.5) | 304 (12.3) | 115 (18.1) | <0.001 |
| Diabetes mellitus, noninsulin dependent | 811 (26.2) | 588 (23.9) | 223 (35.0) | <0.001 |
| Hypertension | 1869 (60.3) | 1412 (57.4) | 457 (71.7) | <0.001 |
| Chronic obstructive pulmonary disease | 258 (8.3) | 203 (8.2) | 55 (8.6) | 0.75 |
| Current or former smoker | 917 (29.6) | 736 (29.9) | 181 (28.4) | 0.53 |
| Coronary artery disease | 390 (12.6) | 305 (12.4) | 85 (13.3) | 0.50 |
| Congestive heart failure | 270 (8.7) | 200 (8.1) | 70 (11.0) | 0.02 |
| Chronic liver disease | 104 (3.4) | 77 (3.1) | 27 (4.2) | 0.17 |
| Active malignancy | 158 (5.1) | 126 (5.1) | 32 (5.0) | 0.92 |
| Kidney transplant | 58 (1.9) | 37 (1.5) | 21 (3.3) | 0.005 |
| CKD, ml/min per 1.73 m2 | <0.001 | |||
| eGFR≥90 | 1033 (33.3) | 887 (36.0) | 146 (22.9) | |
| eGFR=60–89 | 1164 (37.6) | 948 (38.5) | 219 (34.4) | |
| eGFR=45–59 | 419 (13.5) | 323 (13.1) | 96 (15.1) | |
| eGFR=30–44 | 255 (8.2) | 189 (7.7) | 66 (10.4) | |
| eGFR=15–29 | 159 (5.2) | 96 (3.9) | 64 (10.1) | |
| eGFR<15 | 64 (2.1) | 19 (0.8) | 46 (7.2) | |
| Home medications, no. (%) | ||||
| Immunosuppressive medication | 312 (10.7) | 246 (10.0) | 66 (10.4) | 0.77 |
| ACE-I | 566 (18.3) | 431 (17.5) | 135 (21.2) | 0.03 |
| ARB | 513 (16.6) | 359 (14.6) | 154 (24.2) | <0.001 |
| Mineralocorticoid receptor antagonist | 81 (2.6) | 62 (2.5) | 19 (3.0) | 0.49 |
| Statin | 1156 (37.3) | 885 (35.9) | 271 (42.5) | 0.002 |
| NSAID | 260 (8.4) | 199 (8.1) | 61 (9.6) | 0.23 |
| Aspirin | 664 (21.4) | 510 (20.7) | 154 (24.2) | 0.07 |
| Anticoagulant | 272 (8.8) | 230 (9.3) | 42 (6.6) | 0.03 |
| Vital signs on ICU admission, median (IQR) | ||||
| Temperature, °C | 38.1 (37.3–38.9) | 38.0 (37.3–38.9) | 38.2 (37.4–39.0) | 0.002 |
| Systolic BP, mm Hg | 97 (86–111) | 97 (86–111) | 95 (84–111) | 0.21 |
| Heart rate, beats per min | 104 (90–120) | 104 (90–119) | 108 (93–122) | <0.001 |
| Urine output, ml/d | 725 (350–1250) | 800 (430–1325) | 500 (200–930) | <0.001 |
| Laboratory findings on ICU admission, median (IQR) | ||||
| White cell count, per mm3 | 8.2 (5.9–11.5) | 8.0 (5.8–11.3) | 8.9 (6.5–12.2) | <0.001 |
| Lymphocyte count, per mm3 | 824 (561–1152) | 826 (565–1153) | 796 (541–1148) | 0.26 |
| Hemoglobin, g/dl | 12.7 (11.2–14.1) | 12.7 (11.3–14.1) | 12.6 (10.9–14.0) | 0.02 |
| Platelet count, K/mm3 | 214 (164–272) | 215 (164–274) | 207 (164–260) | 0.08 |
| Creatinine, mg/dl | 1.04 (0.80–1.55) | 1.00 (0.77–1.38) | 1.47 (1.0–2.85) | <0.001 |
| Total bilirubin, mg/dl | 0.6 (0.4–0.8) | 0.6 (0.4–0.8) | 0.6 (0.4–0.8) | 0.26 |
| d-dimer, ng/ml | 1310 (700–3263) | 1180 (670–2620) | 2000 (869–6998) | <0.001 |
| C-reactive protein, mg/L | 157 (90–237) | 154 (87–231) | 175 (104–269) | <0.001 |
| IL-6, pg/ml | 56 (19–154) | 50 (18–50) | 100 (29–251) | <0.001 |
| Severity of illness on ICU admission | ||||
| Invasive mechanical ventilation, no. (%) | 2044 (66.0) | 1540 (62.6) | 504 (79.1) | <0.001 |
| FiO2, median (IQR) | 0.8 (0.6–1.0) | 0.8 (0.5–1.0) | 0.9 (0.6–1.0) | <0.001 |
| PEEP, cm of water, median (IQR) | 12 (10–15) | 12 (10–15) | 14 (10–16) | <0.001 |
| PaO2:FiO2, mm Hg, median (IQR)b | 126 (85–194) | 133 (91–204) | 104 (74–104) | <0.001 |
| Noninvasive mechanical ventilation, no. (%) | 54 (1.7) | 46 (1.9) | 8 (1.3) | 0.39 |
| High-flow nasal cannula or NRB, no. (%) | 619 (20.0) | 540 (21.9) | 79 (12.4) | <0.001 |
| Altered mental status on ICU day 1, no. (%) | 681 (22.0) | 552 (22.4) | 129 (20.3) | 0.24 |
| Vasopressors, no. (%) | 1305 (42.1) | 981 (39.8) | 324 (50.9) | <0.001 |
IQR, interquartile range; ACE-I, angiotensin-converting enzyme inhibitor; ARB, angiotensin II receptor blocker; NSAID, nonsteroidal anti-inflammatory drug; FiO2, fraction of inspired oxygen; PEEP, positive end expiratory pressure; NRB, non-rebreather.
a
The definitions of the coexisting disorders are provided in Supplemental Material.
b
PaO2:FiO2 was only assessed in patients receiving invasive mechanical ventilation.