Effect of dexmedetomidine on kidney function induced by in extremity ischemia-reperfusion in diabetic patients

Objective To evaluate the effect of dexmedetomidine on kidney function induced by extremity ischemia-reperfusion in diabetic patients. Methods Sixty diabetic patients of (32 males and 28 females) with ASA physical status Ⅱor Ⅲ, aged 40-64 years, weighing 50-75 kg, were randomly divided into control group and dexmedetomidine group, with 30 patients in each group. All patients were treated by combined spinal epidural anesthesia with the same dose of local anesthetic (0.5% bupivacaine 3 ml) and the same pressure (300 mmHg, 1 mmHg=0.133 kPa) of tourniquet. In dexmedetomidine group, dexmedetomidine 1 μg/kg was infused intravenously for 10 min, followed by continuous infusion of dexmedetomidine at 0.5 μg/(kg·h) until the end of the surgery, while in control group the equal volume of normal saline was given instead. The changes of mean arterial pressure (MAP) and mean heart rate (HR) in each group were recorded at immediately before induction of anesthesia (T0), 5 min after the tourniquet inflated (T1), immediately after tourniquet release(T2), and 5 min after tourniquet release (T3). At T0, T2, 24 h and 72 h after operation(T4, T5), blood samples were collected from the vein for determination of the levels of serum creatinine, blood ureanitrogen, serum cystatin C and 24 h urinary microalbuminuria. Results In control group, the level of MAP at T1 was higher than that at T0: (107 ± 11) mmHg vs. (84 ± 8) mmHg, and there was significant difference (P 0.05). At T4, and T5, the levels of serum cystatin C and 24 h urinary microalbuminuria in two groups were significantly higher than those at T0 (P<0.05), the levels of serum cystatin C and 24 h urinary microalbuminuria in control group were higher than those in dexmedetomidine group: serum cystatin C:(1.17 ± 0.21) mg/L vs. (0.87 ± 0.13) mg/L, (1.09 ± 0.27) mg/L vs.(0.84 ± 0.08) mg/L; 24 h urinary microalbuminuria: (56 ± 19) mg/24 h vs.(27 ± 16) mg/24 h, (54 ± 21) mg/24 h vs. (26 ± 14) mg/24 h, and there were significant differences (P<0.01). Conclusions Dexmedetomidine can attenuate kidney function induced by in extremity ischemia-reperfusion in diabetic patients. Key words: Dexmedetomidine; Reperfusion injury; Extremities; Kidney; Diabetes mellitus