Objective: To study kidney injury in infants with congenital heart disease (CHD) who underwent cardiac surgery with cardiopulmonary bypass (CPB).
Methods: Forty 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.
Results: The 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).
Conclusions: CPB 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.