Acute kidney injury (AKI) is associated with complications that may lead to multiorgan dysfunction and potentially to multi-organ failure after major surgery. Dexmedetomidine is a highly selective alpha(2)-adreno receptor agonist widely used during anesthesia. In animals, dexmedetomidine has shown protective effects in AKI after surgery. Dopamine (DA) is an organic chemical of the catecholamine and phenethylamine families that has been widely used to increased renal blood flow and urine output during surgery. However, the clinical effects of dexmedetomidine and dopamine on renal function are still controversial. The aim of this study is to investigate whether dexmedetomidine and dopamine have positive effects on renal function after selective major surgery.