OBJECTIVETo study kidney injury in infants with congenital heart disease (CHD) who underwent cardiac surgery with cardiopulmonary bypass (CPB).

METHODSForty CHD infants undergoing cardiac surgery with CPB from October 2009 to July 2010 were enrolled. The concentrations of serum tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), cystatin C (CysC) and urinary N-acetyl-beta-D-glucosaminidase (NAG) were detected using ELISA before bypass, at the end of surgery, and 2 hrs, 6 hrs and 24 hrs after surgery. Serum concentrations of creatinine (Cr) and urea nitrogen (BUN) were measured with conventional biochemistry technique before and after surgery.

RESULTSThe concentrations of serum Cr and BUN were normal before and after surgery. After CPB, the concentrations of serum TNF-α and IL-6 and urinary NAG increased significantly (P<0.05). Serum TNF-α was positively correlated with urinary NAG and serum CysC (r=0.195, 0.190, respectively; both P<0.05). Serum IL-6 was positively correlated with urinary NAG (r=0.278, P<0.01). The positive rate in kidney injury was detected by serum CysC and urinary NAG were significantly higher than by serum Cr or BUN (both P<0.01).

CONCLUSIONSCPB can cause acute kidney injury in infants, which may be correlated with the increase in the concentrations of serum TNF-α and IL-6. Serum CysC and urinary NAG may be used as sensitive markers for reflecting the changes of renal function.