The effect of tramadol on serum cytokine response in patients undergoing pulmonary lobectomy

Study Objective: To investigate the effect of tramadol on the production of serum interleukin (IL) 6, IL-10, and IL-2 and soluble (s) IL-2 receptor (R), thereby evaluating its effects on the proinflammatory and anti-inflammatory responses and immune function in cancer patients undergoing conventional pulmonary lobectomy. Design: Randomized, double-blinded, placebo-controlled study. Setting: University hospital. Patients: Forty ASA physical status I and II adult patients scheduled for conventional pulmonary lobectomy. Interventions: Patients were randomly divided into 2 groups (n = 20 in each group). Both groups received general anesthesia with enflurane combined with epidural blockade. At 5 minutes before skin incision, patients were given either tramadol 1.5 mg/kg intravenously (IV), followed by a continuous infusion of 0.5 mg/kg per hour until the end of surgery (group I), or IV normal saline (group II). Measurements and Main Results: Venous blood samples for the measurement of serum cytokine concentrations were taken before anesthesia and at set intervals until 24 hours after operation. Serum levels of IL-6 and IL-10 in both groups were increased significantly during and after operation compared with baseline levels (P <.05). No statistical differences between groups in terms of IL-6 and IL-10 were observed. Levels of IL-2 were elevated significantly at 4 hours after operation in group I as compared with baseline levels (P <.001), whereas they remained low at 4 and 24 hours after operation in group II (P <.01). There were significant increases in levels of sIL-2R at 4 and 24 hours after operation in group II as compared with baseline levels (P <.05) and at 24 hours after operation in group I (P <.01). Levels of IL-2 were higher at 4 and 24 hours after operation in group I than in group II (P <.01). Levels of sIL-2R were lower at 4 hours after operation in group I than in group II (P <.01). Conclusions: IV infusion of tramadol does not seem to alter IL-6/IL-10 cytokine response to pulmonary lobectomy. As tramadol was associated with increased IL-2 and delayed enhancement of sIL-2R in our study, it may attenuate to some extent an impaired immune response in pulmonary lobectomy. (c) 2005 Elsevier Inc. All rights reserved.