Table 1.
Perioperative variable comparisons between the three AKI groups
| Variables | No AKI | Stage 1 AKI | Stage 2–3 AKI | P-value |
|---|---|---|---|---|
| N = 27 | N = 30 | N = 13 | ||
| PREOPERATIVE | ||||
| Male, N (%) | 17 (63) | 19 (63) | 8 (62) | >0.999 |
| Surgery age (days) | 25 (5–150) | 84 (9–150) | 49 (10–60) | 0.521 |
| Neonate (≤30 days), N (%) | 15 (56) | 12 (40) | 4 (31) | 0.276 |
| Surgery weight (kg) | 3.7 (3–6) | 4.6 (3.2–7.1) | 3.5 (3.1–4.4) | 0.193 |
| Surgery BSA (m2) | 0.27 (0.2–0.33) | 0.28 (0.22–0.35) | 0.21 (0.19–0.23) | 0.083 |
| Single ventricle, N (%) | 4 (15) | 5 (17) | 4 (31) | 0.479 |
| Hemoglobin (g/dL) | 12.9 (11.7–15) | 13.4 (11.8–15.3) | 13.1 (11.2–13.7) | 0.254 |
| SpO2 (%) | 91 (84–98) | 93 (87–98) | 91 (87–98) | 0.754 |
| RACHS-1, N (%) | ||||
| 1 | 1 (4) | 0 (0) | 0 (0) | 0.721 |
| 2 | 7 (26) | 12 (40) | 6 (46) | |
| 3 | 6 (22) | 8 (27) | 2 (15) | |
| 4 | 11 (41) | 8 (27) | 3 (23) | |
| 6 | 2 (7) | 2 (7) | 2 (15) | |
| PRISM Score | 12 (6) | 10 (6) | 11 (7) | 0.425 |
| Creatinine (mg/dL) | 0.4 (0.3–0.5) | 0.3 (0.2–0.41) | 0.2 (0.16–0.3) | <0.001* |
| Blood urea nitrogen (mg/dL) | 14 (11–17) | 10 (9–18) | 12 (9–17) | 0.582 |
| INTRAOPERATIVE | ||||
| CPB (min) | 97 (55–113) | 100 (73–128) | 104 (76–127) | 0.548 |
| DHCA, N (%) | 9 (36) | 10 (33) | 3 (33) | >0.999 |
| Platelets (ml) | 205 (171–239) | 174 (145–228) | 169 (124–190) | 0.068 |
| Total products (ml) | 432 (168) | 357 (159) | 371 (207) | 0.247 |
| UOP (ml) | 36 (20–80) | 33 (15–70) | 19 (8–58) | 0.537 |
| Average OR ABP (mm Hg) | 47 (40–51) | 48 (38–53) | 47 (43–51) | 0.723 |
| Average OR CVP (mm Hg) | 10 (8–11) | 10 (8–13) | 9 (7–11) | 0.379 |
| POSTOPERATIVE | ||||
| Average CICU ABP (mm Hg) | 58 (53–66) | 60 (55–64) | 55 (51–60) | 0.613 |
| Average CICU CVP (mm Hg) | 9 (3) | 9 (3) | 11 (3) | 0.341 |
| †Peritoneal drain, N (%) | 13 (48) | 12 (40) | 10 (77) | 0.082 |
| †Peritoneal drain output (ml) | 214 (113) | 205 (138) | 321 (229) | 0.196 |
| Open sternum, N (%) | 13 (52) | 17 (57) | 7 (54) | 0.941 |
| Duration open sternum, (hr) | 44 (22–92) | 68 (42–114) | 68 (40–118) | 0.443 |
| UOP (ml/kg/hr) | ||||
| 12-hour postop | 3.4 (2.2–5.4) | 3.5 (2.3–4.8) | 2.8 (2–3.8) | 0.529 |
| 24-hour postop | 3.4 (2.1–4.5) | 3.2 (2.2–3.9) | 2.9 (1.8–3.4) | 0.37 |
| 48-hour postop | 3.7 (2.8–4.6) | 3.3 (2.7–4.1) | 3.7 (1.8–4.7) | 0.573 |
| Fluid Balance (ml) | ||||
| 12-hour postop | 381 (76–528) | 346 (73–572) | 213 (6–481) | 0.718 |
| 24-hour postop | 88 (226) | 52 (234) | −81 (255) | 0.124 |
| 48-hour postop | −111 (193) | −97 (150) | −173 (187) | 0.437 |
| SvO2 (%) | ||||
| 2-hour postop | 68 (14) | 63 (13) | 67 (18) | 0.394 |
| 12-hour postop | 63 (12) | 60 (11) | 59 (16) | 0.637 |
| 24-hour postop | 68 (10) | 63 (11) | 62 (16) | 0.169 |
| 48-hour postop | 67 (9) | 63 (11) | 64 (12) | 0.431 |
| Lactate (mMol/L) | ||||
| 2-hour postop | 3.4 (2.4–4.7) | 2.9 (2.4–4.3) | 2.6 (2.2–4) | 0.459 |
| 12-hour postop | 2.1 (1.2–3.1) | 1.7 (1.1–2.2) | 2 (1.6–2.7) | 0.272 |
| 24-hour postop | 1.4 (1–1.9) | 1.2 (1–1.4) | 1.3 (1–1.7) | 0.753 |
| 48-hour postop | 1.1 (0.9–1.4) | 1.2 (0.9–1.6) | 1.3 (1–1.5) | 0.581 |
| Creatinine (mg/dL) | ||||
| 2-hour postop | 0.4 (0.3–0.5) | 0.39 (0.3–0.5) | 0.44 (0.37–0.5) | 0.419 |
| 12-hour postop | 0.4 (0.1) | 0.4 (0.1) | 0.4 (0.1) | 0.705 |
| 24-hour postop | 0.35 (0.3–0.4) | 0.3 (0.26–0.4) | 0.4 (0.2–0.5) | 0.896 |
| 48-hour postop | 0.3 (0.2–0.4) | 0.34 (0.2–0.4) | 0.35 (0.24–0.45) | 0.736 |
| CICU LOS (days) | 11 (6–17) | 10 (3–22) | 10 (6–23) | 0.86 |
| Hospital LOS (days) | 16 (10–31) | 15 (8–30) | 29 (9–61) | 0.403 |
| Mechanical ventilation (days) | 3 (2–7) | 3 (0–6) | 4 (3–14) | 0.531 |
Data presented as count (%), median (IQR), or mean (SD)
*
Stage 2–3 AKI had lower preoperative Cr than both Stage 1 AKI (P=0.039) and no AKI (P<0.001), and Stage 1 AKI had lower preoperative Cr than no AKI (P=0.034)
†
Passive peritoneal drains, no patient received peritoneal dialysis
AKI - acute kidney injury; BSA - body surface area; RACHS - Risk Adjustment in Congenital Heart Surgery score; PRISM - Pediatric Risk of Mortality score; CPB - cardiopulmonary bypass; DHCA - deep hypothermic circulatory arrest; UOP - urine output; OR - operating room; ABP - mean arterial blood pressure; CVP central venous pressure; CICU - cardiac intensive care unit; LOS - length of stay