Dexmedetomidina diminui a resposta inflamatória após cirurgia miocárdica sob mini-circulação extracorpórea

Abstract

Despite great technological advances in coronary artery bypass grafting (CABG) surgery, there is a high incidence of cardiac dysfunction and neurocognitive deficits in the postoperative period. Preventive measures are essential to reducing these adverse situations that are responsible for significant morbidity and impairment on life quality of these patients. Surgery and cardiopulmonary bypass (CPB) produces important changes in the immune system, directly involved in the incidence of these complications and is credible that anesthesia choice can it modified. We hypothezised that dexmedetomidine, an (α)-2-agonist, could the inflammatory response to CABG and CPB modified. In a prospective and randomized study, we intend to demonstrate the influence of dexmedetomidine (TIVA-DEX group), as a component of a conventional total intravenous anesthesia (TIVA-propofol+sufentanil) in patients undergoing CABG, with mini-CPB, on the behavior of this inflammatory response. The TIVA-DEX group received a continuous infusion of dexmedetomidine associated to a conventional venous anesthesia (continuous infusion of propofol+sufentanil). Intraoperative dosage of cytokines, such as interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-10 (IL-10), gamma interferon (INF-γ) and tumor necrosis factor (TNF-α) were performed, and also C-reactive protein (CRP), creatine phosphokinase (CPK), creatine phosphokinase-MB (CPK-MB), I troponin (cTnI), cortisol and glucose. The occurrence of lipid peroxidation, by the study of thiobarbituric acid reactive substances (TBARS) and the activity of delta-aminolevulinate dehydratase (δ-ALA-D) to oxidative stress verify were also avaliated. Dexmedetomidine induce a significative reduction of IL-1, IL-6, TNF-α and INF-γ, as compared to group that not receive dexmedetomidine. The levels of IL-10 were decreased in both groups along the time, at a similar pattern. Differences between groups on δ-ALA-D activity do not occur and TBARS was higher in TIVA-DEX group. We concluded that dexmedetomidine associated to TIVA was able to reduce plasma levels of proinflammatory cytokines IL-1, IL-6, TNF-α and INF-γ in patients submitted to CABG surgery under mini-CPB, as compared to a conventional TIVA. These results reinforce literature data about dexmedetomidine potentiality as an anti inflammatory agent.