Table 1.
Patient characteristics
| AKI+/CKD+ (n =679) | AKI−/CKD+ (n =532) | AKI+/CKD− (n =846) | AKI−/CKD− (n =575) | AKI * CKD interaction | |
|---|---|---|---|---|---|
| Demographics | |||||
| Age, years, mean ± SD | 69.4 ± 14.2f | 70.0 ± 14.8f | 62.8 ± 15.8 | 61.5 ± 16.4 | 0.13 |
| Women, (%) | 336 (49.5)e | 284 (53.4)e | 355 (42) | 254 (44.2) | 0.001 |
| African-American, (%) | 261 (38.4)e | 178 (33.5)e | 401 (47.4)b | 238 (41.4) | <0.001 |
| Chronic conditions | |||||
| * Baseline SCr, mg/dl, mean ± SD | 1.80 ± 0.66f | 1.86 ± 0.73f | 0.93 ± 0.24 | 0.92 ± 0.23 | 0.12 |
| * Baseline eGFR, mL/min/1.73m2, mean ± SD | 41.7 ± 11.7bf | 40.0 ± 12.5f | 93.4 ± 36.2 | 92.3 ± 29.7 | 0.04 |
| Diabetes, (%) | 176 (25.9)e | 136 (25.6)e | 170 (20.1) | 99 (17.2) | 0.001 |
| Hypertension, (%) | 181 (26.7)cf | 213 (40.0)e | 432 (51.1) | 297 (51.7) | <0.001 |
| Systolic heart failure, (%) | 30 (4.4) | 15 (2.8) | 25 (3) | 18 (3.1) | 0.36 |
| Anemia, (%) | 600 (89) | 455 (86.7) | 722 (86.4) | 488 (85.6) | 0.26 |
| Drug exposure | |||||
| Diuretic, (%) | 47 (6.9) | 45 (8.5) | 66 (7.8) | 55 (9.6) | 0.12 |
| Statin, (%) | 257 (37.9)f | 185 (34.8)e | 211 (25) | 151 (26.3) | <0.001 |
| Iodine contrast, (%) | 103 (15.2)bf | 115 (21.6)f | 222 (26.2)b | 199 (34.6) | <0.001 |
| Aminoglycoside, (%) | 44 (6.5)e | 33 (6.2)e | 101 (11.9) | 66 (11.5) | <0.001 |
| Critical indicators | |||||
| Oliguria, (%) | 112 (20.2)cd | 24 (5.6) | 105 (14.7)c | 16 (3.3) | 0.002 |
| CFB 72 h, liters, mean ± SD | 4.16 ± 7.34bf | 2.85 ± 5.91 | 5.55 ± 7.50c | 2.74 ± 5.31 | 0.005 |
| FO 72 h, %, mean ± SD | 5.7 ± 9.7e | 4.7 ± 9.1 | 8.0 ± 11.1c | 4.0 ± 7.7 | 0.001 |
| * LOS, days, median [25th–75th percentile] | 12.0 [6.0 – 21.0] | 12.0 [7.0 – 20.0]e | 12.0 [7.0 – 20.0]b | 13.0 [8.0 – 22.0] | 0.07 |
| Pressor or inotrope, (%) | 290 (42.7)c | 144 (27.1) | 366 (43.3)c | 167 (29.0) | <0.001 |
| Mechanical ventilation, (%) | 297 (43.7)b | 190 (35.7) | 407 (48.1)b | 219 (38.1) | <0.001 |
| Blood transfusion, (%) | 19 (2.8) | 19 (3.6) | 29 (3.4) | 18 (3.1) | 0.77 |
| APACHE-II score, mean ± SD | 14.5 ± 7.3c | 12.2 ± 5.8e | 13.4 ± 6.9c | 11.1 ± 6.1 | 0.91 |
| * SOFA score, median [25th–75th percentile] | 5.0 [3.0 – 9.0]c | 4.0 [2.0 – 6.0]e | 5.0 [3.0 – 8.0]c | 3.0 [1.0 – 6.0] | 0.002 |
AKI =occurrence of acute kidney injury; anemia =hematocrit <39% for men and <36% for women; APACHE-II =Acute Physiology and Chronic Health Evaluation II score; CFB 72 h =cumulative fluid balance (total fluid input minus output within the first 72 h of ICU admission); CKD =pre-existing CKD; eGFR =estimated glomerular filtration rate based on Modification of Diet in Renal Disease (MDRD) Study equation, mL/min/1.73m2; FO =fluid overload percentage [(W+CFB/W) − 1] × 100%, W is ICU admission body weight; iodine contrast =only if intravenous or intra-arterial; LOS =length of hospital stay; oliguria =urine output less than 500 mL in 24 h; SCr =serum creatinine; SOFA =Sequential Organ Failure Assessment score.
Data were log-transformed before analysis. Comparisons for categorical variables were made using the Fisher Exact test. For continuous variables, analysis of variance was used for Gaussian and Wilcoxon Rank-Sum test for non-Gaussian distributed data.
p <0.05;
p <0.01;
p <0.0001; AKI vs no AKI for the same CKD status
p <0.05;
p <0.01;
p <0.0001; CKD vs no CKD for the same AKI status