Effect of dexmedetomidine on the inflammatory response and acute kidney injury in patients treated with coronary artery bypass grafting under cardiopulmonary bypass

Objective To investigate the effects of dexmedetomidine on the inflammatory response and acute kidney injury in patients treated with coronary artery bypass grafting under cardiopulmonary bypass.

Methods Sixty patients scheduled by coronary artery bypass grafting under cardiopulmonary bypass were randomly divided into the dexmedetomidine group(groupD) and control group(groupC) (30 cases in each group).After anesthesia induction, the group D were treated with 1 μg/kg of dexmedetomidine by intravenous pump for 10 minutes, and then 0.4 μg·kg^-1·h^-1 of dexmedetomidine by intravenous continuous pump until the end of operation.In group C, the same volume of 0.9% sodium chloride solution was pumped intravenously in the same way.The blood samples from internal jugular vein and urine samples were collected before induction of anesthesia(T₀), end of cardiopulmonary bypass(T₁), end of operation(T₂), and after 6 h(T₃), 24 h(T₄), 48 h(T₅), 72 h(T₆) of operation.The serum concentrations of tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), C-reactive protein(CRP), serum creatinine(SCr), blood urea nitrogen(BUN) and serum cystain C(CysC) were detected.The glomerular filtration rate(GFR) at each time-point were calculated, and the levels of neutrophils gelatinase-associated lipid delivery protein(NGAL), kidney injury molecule-1(KIM-1) and β₂-microglobulin(β₂-MG) in urine were detected in two groups.

Results Compared with T₀, the differences of SCr and CysC concentrations between two groups were not statistically significant from T₁ to T₆ (P>0.05).Compared with T₀, the levels of TNF-α, IL-6, CRP, BUN, NGAL, KIM-1 and β₂-MG increased, and the eGFR decreased in two groups from T₁ to T₆(P < 0.05 to P < 0.01).Compared with the group C, the concentrations of TNF-α and IL-6 in group D decreased at T₁ to T₆, the NGAL and KIM-1 levels decreased at T₂ to T₆, the CRP and β2-MG levels decreased at T₃ to T₆, the eGFR values increased at T₄ to T₆, and the BUN levels decreased at T₅ to T₆(P < 0.05 to P < 0.01).

Conclusions Dexmedetomidine can reduce the degree of inflammatory response caused by coronary artery bypass grafting under cardiopulmonary bypass, and has a protective effect on acute kidney injury.