The purpose of this study is to demonstrate the efficacy of erythropoietin for prevention acute kidney injury in CKD patients undergoing cardiac surgery.

Acute kidney injury (AKI)occur 7.7-42% after cardiac surgery. The incidence of AKI requiring renal replacement therapy following coronary artery bypass grafting (CABG) surgery was 0.7-3.5% and increase mortality rate. Erythropoietin (EPO) is now considered a novel anti-apoptotic and anti-inflammatory action. The present study was designed to evaluate the administration of EPO as a means of preventing AKI in these patients.

Inclusion Criteria:

• age > 18 years.
• serum creatinine levels > 1.2 mg/dL and baseline creatinine clearance levels < 60 mL/min (as measured in their most recent sample,drawn within 2 months prior to the beginning of the study)
• patients who need cardiac surgery

Exclusion Criteria:

• patients with acute kidney injury
• end stage renal disease (requiring dialysis)
• unstable renal function (as evidenced by a change in serum creatinine of > 0.5 mg/dL, or > 25%, within 14 days prior to the study)
• allergy to any of erythropoietin
• suffered from congestive heart failure, cardiogenic shock or emergent cardiac surgery.
• receiving erythropoietin within 14 days before the study