Effects of dexmedetomidine on the ratio of T helper 1 to T helper 2 cytokines in patients undergoing laparoscopic cholecystectomy.

STUDY OBJECTIVES: To investigate the effect of dexmedetomidine on T helper 1 (Th1) and T helper 2 (Th2) cytokines and their ratio during and after surgery. DESIGN: Single-blinded, randomized, placebo-controlled clinical comparison study. SETTING: Academic medical center. PATIENTS: 46 adult, ASA physical status 1 and 2 patients scheduled for laparoscopic cholecystectomy. INTERVENTIONS: Patients were randomized to two groups: the dexmedetomidine group (n = 23), in which dexmedetomidine was infused with a 1.0 µg/kg loading dose followed by infusion of 0.5 µg/kg/h; or the saline group (n = 23). MEASUREMENTS: Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) as Th1 and Th2 cytokines, respectively, were quantified three times: after induction of anesthesia (T0), at the end of peritoneal closure (T1), and 60 minutes after surgery (T2). The IFN-gamma/IL-4 ratio was then calculated. MAIN RESULTS: The dexmedetomidine group displayed higher levels of IFN-gamma at T1 and T2 (42.30 pg/dL vs 6.91 pg/dL at T1 [P = 0.025]; 40.51 pg/dL vs 8.29 pg/dL at T2 [P = 0.030]) than the saline group. The dexmedetomidine group was also associated with higher ratios of IFN-gamma/IL-4 (1.22 vs 0.32, respectively, at T1 [P = 0.012]; 1.53 vs 0.13, respectively, at T2 [P = 0.012]). CONCLUSIONS: Dexmedetomidine plays an immunomodulatory role, shifting the Th1/Th2 cytokine balance toward Th1 in patients with surgical and anesthetic stress.