[Postoperative abnormal liver function in children with heart surgery]

To investigate the incidence of postoperative abnormal liver function test (aLFT) for the children with heart surgery, and to analyze the clinical characteristics and risk factors.
 Methods: A total of 143 children younger than 18 years old who underwent heart surgery in 2017 were enrolled in this study. The liver function were examined one day preoperation and consecutive 5 days after operation. The clinical data of perioperative period were recorded and the risk factors for aLFT were analyzed.
 Results: There were 43/143 (30%) cases had aLFT, including 5/143 (3.5%) acute liver injury (ALI). In the 6 liver function tests, total bilirubin, and glutamic-oxalacetic aminotransferase and glutamic-pyruvic aminotransferase increased to the peak at the first day and the second day after operation, respectively, and albumin declined to the lowest level at the fourth day after operation. aLFT happened most common at the first day after operation(22/43, 51.2%). The patients in the aLFT(+) group had smaller body size, more proportion of the risk adjustment for congenital heart sugery-1 (RACHS-1) score ≥ 3 and cyanosis, longer cardiopulmonary bypass (CPB) time, higher postoperative cardiac troponin (cTnI) value, higher inotropic score (IS), more transfusion, and longer mechanical ventilation time than those in the aLFT(-) group. The aLFT(+) group had longer ICU and hospital time, higher morbidity and mortality than those in the aLFT(-) group (P<0.05). Logistic regression showed that RACHS-1≥3, cyanosis, CPB time, cTnI, IS, transfusion, and mechanical ventilation time were the risk factors for aLFT. Multiple factor analysis showed the mechanical ventilation time was an independent risk factor for aLFT (P<0.05).
 Conclusion: aLFT is common in children after congenital heart operation, which could deteriorate to poor outcome. The mechanical ventilation time is an independent risk factor for aLFT.