Table 3.
Baseline and peri-operative characteristics of patients with and without different stages of acute kidney injury
| Non-AKI (n = 911) | Mild AKI (n = 209) | Moderate to severe AKI (n = 64) | P-value | |
| Baseline characteristics | ||||
| Female | 449 (49.3) | 94 (45.0) | 26 (40.6) | 0.251 |
| Age at surgery (months) | 29.2 [10.7 to 47.8] | 11.2 [5.6 to 27.5] | 5.7 [3.8 to 12.3] | <0.001 |
| Weight (kg) | 12.5 ± 5.0 | 9.7 ± 4.2 | 7.3 ± 3.0 | <0.001 |
| Gestational age (weeks) | 39 [38 to 40] | 39 [38 to 40] | 38 [37 to 40] | 0.140 |
| Preoperative data | ||||
| Previous cardiac surgery | 46 (5.0) | 10 (4.8) | 2 (3.1) | 0.786 |
| RACHS-1> = 3 | 367 (40.2) | 98 (46.9) | 34 (53.1) | 0.041 |
| LVEF (%) | 69 [65 to 73] | 68 [65 to 72] | 70 [65 to 72] | 0.572 |
| MAP (mmHg) | 68 [64 to 71] | 66 [63 to 70] | 64 [62 to 67] | <0.001 |
| Serum creatinine (μmol l−1) | 29 [23 to 36] | 24 [19 to 30] | 20 [17 to 22] | <0.001 |
| Haemoglobin (g dl−1) | 12.2 [11.4 to 12.9] | 11.6 [10.8 to 12.3] | 11.2 [10.2 to 12.3] | <0.001 |
| Use of diuretics | 63 (6.9) | 21 (10.0) | 9 (14.1) | 0.052 |
| Intra-operative data | ||||
| CPB duration (min) | 68 [47 to 94] | 76 [53 to 122] | 103 [69 to 145] | <0.001 |
| ACC duration (min) | 42 [26 to 63] | 47 [29 to 70] | 61 [45 to 95] | <0.001 |
| Blood transfusion | 52 (5.7) | 17 (8.1) | 9 (14.1) | 0.021 |
| Fluid administration (ml kg−1) | 4.7 [3.3 to 7.4] | 6.6 [4.3 to 8.9] | 8.2 [5.6 to 10.9] | <0.001 |
| Urine output (ml kg−1h−1) | 2.7 [1.4 to 4.9] | 2.7 [1.3 to 5.2] | 2.4 [1.5 to 5.5] | 0.964 |
| Use of furosemide | 704 (77.3) | 165 (78.9) | 54 (84.4) | 0.387 |
| Furosemide dose (mg kg−1) | 0.4 [0.2 to 0.5] | 0.5 [0.3 to 0.7] | 0.7 [0.4 to 0.9] | <0.001 |
| Blood loss (ml kg-1) | 1.2 [0.9 to 1.7] | 1.4 [1.1 to 1.9] | 2.1 [1.5 to 2.6] | <0.001 |
| Vasoactive-inotropic score | 12 [6 to 12] | 12 [10 to 16] | 12 [12 to 16] | <0.001 |
| Haemoglobin after CPB (g dl−1) | 8.8 [8.2 to 9.7] | 9.0 [8.1 to 9.7] | 8.8 [7.9 to 9.5] | 0.324 |
| Lowest haemoglobin (g dl−1) | 9.3 [8.7 to 9.7] | 9.3 [8.7 to 9.6] | 9.2 [8.8 to 9.5] | 0.005 |
| Lowest core temperature during CPB (°C) | 33.1[31.7 to34.2] | 32.0 [30.9 to 33.4] | 31.2 [30.2 to 32.1] | <0.001 |
| Modified ultrafiltration | 737 (80.9) | 193 (92.3) | 60 (93.8) | <0.001 |
| Postoperative outcomes | ||||
| Length of MV (h) | 3 [0 to 5] | 4 [0 to 12] | 7 [0 to 65] | <0.001 |
| Length of ICU stay (days) | 2 [1 to 3] | 2 [1 to 4] | 4 [2 to 11] | <0.001 |
| Length of hospital stay (days) | 6 [5 to 8] | 7 [5 to 9] | 9 [6 to 13] | <0.001 |
Data are given as n (%), median [IQR] or mean ± SD as appropriate.
ACC, aortic cross-clamp; CPB, cardiopulmonary bypass; ICU, intensive care unit; LVEF, left ventricular ejection fractions; MAP, mean arterial pressure; MV, mechanical ventilation; RACHS-1, risk adjustment in congenital heart surgery-1 method.