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.