[Association between fluid overload and acute renal injury after congenital heart disease surgery in infants].

OBJECTIVE: To study the association between fluid overload and acute kidney injury (AKI) after congenital heart disease surgery in infants.

METHODS: A retrospective analysis was performed on 88 infants aged less than 6 months who underwent a radical surgery for congenital heart disease. The treatment outcomes were compared between the infants with AKI after surgery and those without. The effect of cumulative fluid overload on treatment outcomes 2 days after surgery was analyzed. The risk factors for the development of AKI after surgery were assessed by logistic regression analysis.

RESULTS: Compared with those without AKI after surgery, the patients with AKI had younger age, lower body weights, higher serum creatinine levels and higher vasoactive-inotropic score, as well as longer durations of intraoperative extracorporeal circulation and aortic occlusion (P<0.05). Compared with those without AKI after surgery, the patients with AKI had a higher transfusion volume, a higher incidence rate of low cardiac output syndrome, a longer duration of mechanical ventilation, a longer length of stay in the intensive care unit (ICU), a longer length of hospital stay, a higher application rate of extracorporeal membrane oxygenation, a higher 30-day mortality rate, and higher levels of cumulative fluid overload 2 and 3 days after surgery (P<0.05). The logistic regression analysis showed that fluid overload and low cardiac output syndrome were major risk factors for the development of AKI after surgery. The children with cumulative fluid overload >5% at 2 days after surgery had a higher incidence rate of low cardiac output syndrome, a longer duration of mechanical ventilation, a longer length of stay in the ICU, a longer length of hospital stay, and a higher mortality rate (P<0.05).

CONCLUSIONS: Infants with fluid overload after surgery for congenital heart disease tend to develop AKI, and fluid overload may be associated with poor outcomes after surgery.