Dexmedetomidine exerts a protective effect on ischemia-reperfusion injury after hepatectomy: A prospective, randomized, controlled study.

STUDY OBJECTIVE: Dexmedetomidine, a highly selective α2 -receptor agonist, has been widely used for protection against ischemia-reperfusion (IR) injury. We hypothesized that dexmedetomidine might exert a protective effect on IR injury after hepatectomy.

DESIGN: A prospective, randomized, single-blind study was conducted in 58 patients undergoing hepatectomy who were randomly assigned to two study groups. The dexmedetomidine group (D group) received a loading dose of 0.5 μg/kg for 10 min, and maintained it with 0.5 μg/kg/h until resection of the liver lobes. The control group (C group), received 0.9% sodium chloride administered in the same volume and infusion rate as D group. Eleven patients had hepatic inflow occlusion in D group as did 14 patients in C group.

MEASUREMENTS: The primary outcome was the serum concentration of α-glutathione S-transferase (α-GST), which reflects hepatic ischemic injury. Secondary outcomes included laboratory variables reflecting inflammatory responses, liver and kidney function, and blood coagulation, as well as hemodynamic changes, recovery variables, and complications related to anesthesia and surgery.

RESULTS: The concentration of α-GST at 0.5 h after resection was significantly lower in the dexmedetomidine group than the control group (9.1 ± 3.4 ng/mL vs 15.8 ± 6.5 ng/mL; p < .01), and was also significantly lower in the dexmedetomidine group in subgroup analyses of patients with and without hepatic inflow occlusion. While the concentrations of α-GST at 0.5 h after resection in patients with or without occlusion in D group were comparable, in C group the α-GST concentration without occlusion was significantly higher than that with occlusion. There was an interaction between dexmedetomidine and no occlusion (p < .01), and its concentration in D group without occlusion was the lowest of all subgroups. In addition, there were significant differences in interleukin (IL)-6 and tumor necrosis (TNF)-α concentrations at 24 h after hepatectomy between the two groups, and mean arterial pressure, heart rate, and the bispectral index were also significantly lower in D group than in C group (p < .05). There were significant differences between the two groups in ALT and AST at 2 h and 24 h after the resection of the liver lobe. However, there were no significant differences in renal function, recovery variables, blood coagulation. No severe complications related surgeries and anesthesia were found in both groups.

CONCLUSION: Dexmedetomidine exerts a protective effect on ischemia-reperfusion injury after hepatectomy.