MON-246 LONG TERM RENAL OUTCOMES IN CHILDREN WITH ACUTE KIDNEY INJURY POST CARDIAC SURGERY [ROCKS TRIAL]- RESULTS OF ISN CLINICAL RESEARCH PROGRAM GRANT

Abstract

Numerous studies have shown that acute kidney injury (AKI) is associated with poor short-term outcomes such as mortality, longer ICU/hospital length of stay, and duration of ventilation. However, the long-term renal outcomes of survivors of pediatric AKI have not been studied extensively. Objective: To study the long-term renal outcomes and markers of kidney injury in pediatric patients who did and did not develop AKI following cardiac bypass surgery. In a prospective case-control observational study, all infants and children who underwent cardiac bypass surgery (December 2010 - December 2017) and had a long term follow up were evaluated. Cases were defined as patients who developed AKI and were matched to consecutive controls who did not develop AKI post operatively. Patients were excluded if they had pre-existing CKD (including kidney transplant, long-term dialysis), history of hypertension, AKI from a primary kidney disease (such as acute glomerulonephritis or obstructive uropathy), and a previous history of AKI. Patient demographics and clinical characteristics were documented at the time of surgery, and renal function and kidney injury biomarkers were studied. Evaluation consisted of estimated GFR (measured by Schwartz formula and by Cystatin-C), serum blood urea nitrogen, serum creatinine, urine albumin/creatinine ratio, serum cystatin C levels, serum Beta-trace protein. Urinary biomarkers consisted of NGAL, L-FABP, KIM-1 and IL-18. During the study period 2,035 patients underwent cardiopulmonary bypass of whom 9.8% (200/2,035) developed AKI post operatively. Forty four patients who had postoperative AKI, had a long term follow up, and met our inclusion criteria and therefore they were matched to 49 controls. There were no significant differences between cases and controls at the time of surgery, except that patients who developed AKI had a higher baseline serum creatinine, a higher postoperative serum creatinine, a longer ICU length of stay, and a trend towards a larger weight, a longer CPB time, and a higher rate of sepsis than their controls. At follow-up, patients with post-operative AKI had a higher serum creatinine level, and a trend towards higher urinary KIM-1 levels, and a lower estimated GFR. Since there was a significant difference between children who did and did not develop AKI post operatively, a backward linear regression analysis was conducted with GFR as the dependent variable, and weight, baseline serum creatinine, post-operative AKI, CPB time, and sepsis as independent variables. CPB time remained the only risk factor associated with GFR at follow up [Figure 1a]. A backward linear regression analysis was conducted with KIM-1 as the dependent variable, and weight, baseline serum creatinine, post-operative AKI, CPB time, and sepsis as independent variables. CPB time, baseline serum creatinine and AKI remained the only risk factors associated with KIM-1 [Figure 1b]. In children with congenital heart disease, cardiopulmonary bypass time is significantly associated with a decrease in GFR and a rise in kidney injury biomarker KIM-1 level several months post operatively independent of postoperative AKI.