[Effects of subanesthetic dose of ketamine on perioperative serum cytokines in orthotopic liver transplantation].

Objective: To evaluate the effects of ketamine on perioperative serum cytokine levels in patients undergoing orthotopic liver transplantation (OLT).

Methods: Twenty patients undergoing OLT were randomly divided into ketamine group (n=10) and control group (n=10). Patients in ketamine group were given intravenous bolus injection of ketamine at 0.25 mg/kg followed by ketamine infusion at 0.5 mg.kg(-1).h(-1) until the end of operation except in the anhepatic phase, whereas the control group received saline of the same amount. Arterial blood samples were obtained at the start of surgery (T(1)), 5 min before the anhepatic phase (T(2)), 5 min before recirculation (T(3)), 15 and 60 min after recirculation (T(4), T(5)), and 0, 4 and 24 h after operation (T(6), T(7), T(8)). Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and IL-10 were measured by ELISA.

Results: Serum TNF-alpha, IL-6 and IL-10 levels increased significantly during anhepatic phase as compared with the baseline level (T(1)) (P<0.05), and the changes were especially obvious in IL-6 and IL-10. The levels of the cytokines kept rising after recirculation and reached the peak level at T(5)(P<0.05), followed then by rapid decline and still maintaining higher levels than the preoperative ones 24 h after operation. The levels of TNF-alpha in ketamine group between T(2) and T(7) were significantly lower than that in the control group, and the IL-6 level between T(2) and T(5) were also significantly lower in ketamine group. Serum IL-10 level did not show any significant difference between the two groups.

Conclusion: Ischemia and reperfusion injury of the liver and surgical stress induce pro- and anti-inflammatory cytokine responses during liver transplantation, in which event IL-6 and IL-10 are more sensitive than TNF-alpha. Ketamine can inhibit the production of TNF-alpha and IL-6 but not IL-10.