Impairment of renal function after cardiopulmonary bypass is not influenced by dopexamine

Introduction: The objective of this study was to evaluate the effects of do pexamine on renal function in 4 groups of patients either with or without r enal dysfunction. Transient renal dysfunction is often not clinically relev ant in patients with normal renal function, but it is an important clinical factor in patients with pre-existing renal failure. Dopexamine (DX) is a c ommonly used catecholamine which probably exerts a selective effect at the splanchnic bed. Material and Methods: 24 patients with normal renal functio n and 24 patients with impaired renal function (creatinine in serum greater than or equal to 1.5 mg/dL) were each randomly allocated to 2 groups. Grou p 1 (control) without renal dysfunction and group 3 (control/dysfunction) w ith renal dysfunction were considered as control groups, while the patients in DX and DX/dysfunction groups received I mug/kg/min dopexamine until the end of surgery. Kidney function was investigated using standard parameters and by investigating specific proteins and enzymes. Results: All patients showed pathologic excretions of the investigated parameters during cardiopu lmonary bypass (CPB) with no differences between the study groups. The dist al tubule, the lysosomal regions, Henle's loop and the glomerular tuft were all damaged. Heart rate and cardiac index increased significantly in the D X-groups, first until the end of surgery, second until the start of ECC. Co nclusion: Dopexamine, at a dose of I mug/kg/min had no influence on renal f unction and protein excretion and cannot be regarded as a kidney function p rotecting substance.