Effect of dexmedetomidine on myocardial ischemia-reperfusion injury.

Cardiopulmonary bypass (CPB) is associated with a marked systemic inflammatory response. Although dexmedetomidine (Dex) is routinely used in cardiac surgery, the effect in reducing the inflammatory response in coronary artery bypass graft surgery (CABG) with CPB remains unclear. In this study, Dex was administered at a loading dose of 0.5 μg/kg for 10 min, followed by a continuous infusion of 0.5 μg/kg per hour until the completion of CABG with CPB. The levels of inflammatory cytokines in the serum, including tumor necrosis factor-alpha (TNFalpha), interleukin (IL)-6, IL-8 and IL-10, were measured to explore the inflammatory regulating function of Dex. In addition, troponin-I (cTnI) and creatine kinase (CK-MB) levels were studied to explore the myocardial protection provided by Dex. In this study, we showed Dex inhibited the increase in cTnI and CK-MB, attenuated the production of pro-inflammatory cytokines TNF-alpha, IL-6 and IL-8, and promoted anti-inflammatory cytokine IL-10 production. These findings demonstrate that Dex regulates anti-inflammatory as well as myocardial protection potential in CABG with CPB.