Introduction Cardiac surgery with cardiopulmonary bypass (CPB) is commonly perceived as a risk factor for decline in renal function. Hypothermia, hypoxia, hypotension, non-pulsatile blood flow during CPB, use of ACE inhibitors, inotropic and (or) vasoactive support affects kidney and contributes to the acute kidney injury (AKI).
Objective To evaluate dynamics of renal biomarkers - serum creatinine (SCr) and glomerular filtration rate (GFR) in children undergoing open heart surgery.
Methods We conducted prospective, non-randomized observational study at the tertiary care University Children’s Hospital Pediatric ICU. We enrolled 30 patients, 12 boys and 18 girls with CHD. Their median body weight was 6.8 kg, (IQR 5.2< 8.2 kg) and median age 7 months (IQR 5< 10 months). SCr was determined and preoperative and postoperative creatinine clearance (ClCr) was estimated using Schwarz formula. During surgical repair and till the end of the first 24 hours urine was collected to measure ClCr, using the difference in urine (UCr) and SCr concentrations. Urine output, body temperature, duration of aortic cross clamping and cardiopulmonary bypass was recorded.
Results Median intraoperative urine output was 2.4 ml/kg/h (IQR 1.29< 3.15 ml/kg/h). Intraoperative SCr rised to 35 µmol/l (IQR 27.5< 50.5) vs preoperative SCr 29 µmol/l (IQR 24< 32.9), p<0,0001. GFR declined from preoperative 98.4 ml/min./1.73 m2 (IQR 89.6< 123.04) to intraoperative 39.8 ml/min./1.73 m2, (IQR 24.9< 65.5), p<0,0001.
Conclusion Open heart surgery in children has severe, but transient effect on expression of renal biomarkers. Before discharge from the hospital both biomarkers returned to normal values.