Table 5. Comparison of clinical information and outcomes in various stages of CSA-AKI.
| Variables | Total (n=689) | Non-AKI (n=488) | AKI stage 1 (n=132) | AKI stage 2 (n=48) | AKI stage 3 (n=21) | P value |
|---|---|---|---|---|---|---|
| Male, n (%) | 417 (60.5) | 308 (63.1) | 75 (56.8) | 24 (50.0) | 10 (47.6) | 0.12 |
| Age (years) | 57.0 (48.0, 64.0) | 55.0 (46.0, 62.0) | 62.5 (54.0, 68.0) | 62.0 (54.8, 67.2) | 65.0 (53.0, 68.0) | <0.001* |
| Weight (kg) | 60.0 (53.0, 67.0) | 60.0 (53.0, 67.0) | 58.0 (52.0, 67.0) | 57.2 (52.5, 67.2) | 56.0 (52.5, 70.0) | 0.75 |
| Medical history | ||||||
| Hypertension | 158 (22.9) | 87 (17.8) | 47 (35.6) | 14 (29.2) | 10 (47.6) | <0.001* |
| Diabetes mellitus | 62 (9.0) | 35 (7.2) | 17 (12.9) | 7 (14.6) | 3 (14.3) | 0.047 |
| Hyperlipidemia | 5 (0.7) | 4 (0.8) | 0 (0.0) | 0 (0.0) | 1 (4.8) | 0.19 |
| CAD | 12 (1.7) | 6 (1.2) | 6 (4.5) | 0 (0.0) | 0 (0.0) | 0.10 |
| CKD | 5 (0.7) | 2 (0.4) | 2 (1.5) | 0 (0.0) | 1 (4.8) | 0.01 |
| Nephrotoxic drugs | 33 (4.8) | 23 (4.7) | 5 (3.8) | 4 (8.3) | 1 (4.8) | 0.07 |
| Pre-op LVEF (%) | 63.0 (57.0, 67.0) | 63.0 (57.0, 67.0) | 63.0 (55.0, 67.0) | 62.0 (54.8, 66.0) | 64.0 (57.0, 66.0) | 0.86 |
| Pre-op examination | ||||||
| Hemoglobin (g/L) | 134.0 (120.0, 145.0) | 136.0 (123.0, 146.0) | 129.0 (115.8, 138.0) | 128.5 (118.0, 141.5) | 125.0 (96.0, 142.0) | 0.001* |
| D-Dimer (ng/mL) | 360.0 (240.0, 830.0) | 330.0 (220.0, 722.5) | 510.0 (295.0, 1,132.5) | 390.0 (275.0, 915.0) | 670.0 (320.0, 1,190.0) | <0.001* |
| Albumin (g/L) | 38.5 (36.3, 40.9) | 38.8 (36.6, 41.3) | 37.7 (35.1, 39.6) | 38.1 (36.0, 40.6) | 37.0 (32.5, 40.1) | 0.001* |
| Baseline sCr (µmol/L) | 78.0 (65.3, 93.6) | 78.5 (66.8, 92.7) | 76.8 (62.7, 96.4) | 79.5 (63.3, 91.0) | 82.1 (71.1, 150.5) | 0.25 |
| Surgical procedures | ||||||
| Valve surgery | 545 (79.1) | 400 (82.0) | 94 (71.2) | 32 (66.7) | 19 (90.5) | 0.18 |
| CABG | 51 (7.4) | 30 (6.1) | 15 (11.4) | 6 (12.5) | 0 (0.0) | 0.06 |
| CABG + valve surgery | 44 (6.4) | 23 (4.7) | 12 (9.1) | 7 (14.6) | 2 (9.5) | 0.02* |
| Other procedures | 49 (7.1) | 35 (7.2) | 11 (8.3) | 3 (6.2) | 0 (0.0) | 0.71 |
| Intra-op data | ||||||
| CPB duration (min) | 145.0 (113.0, 186.0) | 135.0 (106.8, 173.0) | 172.0 (125.0, 200.0) | 189.5 (139.0, 251.8) | 175.0 (143.0, 211.0) | <0.001* |
| ACC duration (min) | 88.0 (64.0, 118.0) | 84.0 (62.0, 110.0) | 104.0 (70.0, 129.2) | 104.5 (74.8, 147.2) | 102.0 (86.0, 142.0) | <0.001* |
| Minimum temperature (℃) | 31.0 (30.1, 31.9) | 31.1 (30.3, 32.0) | 30.9 (30.0, 31.8) | 30.8 (29.6, 31.6) | 30.6 (29.7, 31.4) | 0.03* |
| Intra-op transfusion | ||||||
| RBC (U) | 2.0 (1.5, 2.6) | 1.8 (1.3, 2.3) | 1.9 (1.4, 2.5) | 1.8 (1.3, 2.4) | 2.0 (1.5, 2.5) | 0.09 |
| Hydroxyethyl starch (mL) | 354.5 (288.6, 424.3) | 326.5 (276.7, 378.9) | 365.5 (316.0, 410.7) | 398.3 (338.4, 454.5) | 386.5 (326.7, 448.9) | 0.27 |
| Emergency surgery | 20 (2.9) | 9 (1.8) | 6 (4.5) | 3 (6.3) | 2 (9.5) | 0.02* |
| Post-op data | ||||||
| APACHE II scores | 9.8 (6.8, 12.8) | 8.6 (6.2, 11.0) | 10.3 (8.1, 12.6) | 12.2 (9.7, 14.6) | 13.8 (11.7, 15.9) | <0.001* |
| sCysC (mg/L) | 1.0 (0.8, 1.3) | 0.9 (0.7, 1.1) | 1.1 (0.9, 1.4) | 1.4 (1.1, 1.9) | 1.9 (1.2, 2.6) | <0.001* |
| uNAG (U/g Cre) | 8.0 (1.6, 20.8) | 4.8 (1.3, 18.2) | 10.9 (3.2, 18.6) | 19.3 (10.6, 32.4) | 24.2 (20.8, 30.5) | <0.001* |
| CK (U/L) | 530.0 (393.0, 746.0) | 505.0 (365.0, 690.2) | 547.5 (422.0, 778.0) | 754.0 (533.8, 952.5) | 643.0 (448.0, 843.0) | <0.001* |
| CK-MB (U/L) | 61.2 (42.2, 87.8) | 58.9 (40.3, 83.0) | 69.8 (47.7, 93.5) | 76.0 (48.9, 117.6) | 69.1 (50.0, 119.0) | 0.001* |
| NT-proBNP (pg/mL) | 1,565.0 (636.6, 3,556.0) | 1,336.2 (536.9, 2,864.2) | 2,451.0 (901.0, 4,523.2) | 2,549.5 (1,047.8, 5,253.5) | 3,678.0 (2,115.0, 13,684.0) | <0.001* |
| cTnI (ng/mL) | 654.6 (304.4, 1,183.0) | 554.5 (265.8, 1,027.0) | 843.6 (396.6, 1,507.0) | 985.5 (669.6, 2,555.0) | 1,076.0 (864.7, 2,657.0) | <0.001* |
| Outcomes | ||||||
| ICU LOS (h) | 45.0 (27.0, 112.0) | 42.0 (22.0, 68.2) | 85.0 (40.8, 161.2) | 134.0 (79.2, 212.5) | 222.0 (154.0, 383.0) | <0.001* |
| CRRT | 19 (2.8) | 4 (0.8) | 3 (2.3) | 4 (8.3) | 8 (38.1) | <0.001* |
| IABP | 43 (6.2) | 16 (3.3) | 9 (6.8) | 11 (22.9) | 7 (33.3) | <0.001* |
| ECMO | 11 (1.6) | 5 (1.0) | 1 (0.8) | 3 (6.3) | 2 (9.5) | 0.005* |
| MV (h) | 20.0 (13.0, 43.0) | 17.0 (10.8, 24.0) | 25.0 (18.0, 72.2) | 65.0 (37.5, 142.2) | 132.0 (47.0, 218.0) | <0.001* |
| Hospital costs (10k CNY) | 14.8 (11.8, 19.4) | 13.5 (10.8, 16.9) | 17.8 (14.1, 23.3) | 21.6 (18.0, 27.4) | 30.0 (20.8, 36.8) | <0.001* |
| In-hospital mortality | 20 (2.9) | 5 (1.0) | 3 (2.3) | 8 (16.7) | 4 (19.0) | <0.001* |
Data were presented as median (interquartile range) or n (%). *, there is a statistical difference. CSA-AKI, cardiac surgery-associated acute kidney injury; CAD, coronary artery disease; CKD, chronic kidney disease; Nephrotoxic drugs, including immunosuppressants, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, non-steroidal anti-inflammatory drugs, antibiotics (including vancomycin, acyp-clovir, amphotericin B, aminoglycosides), mannitol, angiography agents, etc.; Pre-op, preoperative; LVEF, left ventricular ejection fraction; CABG, coronary artery bypass grafting; Other procedures, including correction of congenital heart disease, repair of aortic sinus aneurysm, etc.; Intra-op, intraoperative; CPB, cardiopulmonary bypass, ACC, aortic cross clamping; RBC, red blood cell; Post-op, postoperative; APACHE, acute physiologic and chronic health evaluation; sCysC, serum cystatin C; uNAG, urine N-acetyl-β-D-glucosidase; NT-proBNP, N-terminal B-type natriuretic peptide precursor; cTnI, cardiac troponin I; ICU LOS, intensive care unit length of stay; CRRT, continuous renal replacement therapy; IABP, intra-aortic balloon pump; ECMO, extracorporeal membrane oxygenation; MV, mechanical ventilation; CNY, Chinese yuan.