Perfil das citocinas e correlação com a morbidade no período pós-operatório em crianças com diagnostico de cardiopatias congênitas não cianosantes submetidas a cirurgia corretiva com circulação extracorpórea

Abstract

Pediatric cardiac surgery with cardiopulmonary bypass (CPB) induces a complex inflammatory reaction of variable intensity that, in severe cases, may lead to multiple organ dysfunctions, resulting in considerable morbidity and mortality. Previous studies have demonstrated the involvement of cytokines with both pro-­inflammatory and anti-­ inflammatory profile in the inflammatory response in this group of patients, as well as its relationship to morbidity in the postoperative period. The present study aimed to delineate the kinetics of plasma concentrations of eight different cytokines, to determine the impact of blood transfusion on these kinetics and to evaluate the possible correlation of postoperative morbidity with these kinetics. This study evaluated a group of 19 children diagnosed with non-­cyanotic congenital heart disease with volume overload of left ventricle and increased pulmonary blood flow, classified as low risk for operative mortality, undergone corrective surgery with CPB. Blood samples were taken in seven different times: after induction of anesthesia but prior to initiation of surgery (T0), five minutes after CPB beginning (T1), five minutes after the opening of the aortic clamp (T2), at the end of surgical procedure (T3), four hours after the end of surgery (T4), at the first postoperative day (T5) and at the second postoperative day (T6). For each sample was carried out the measurement of plasma concentrations of interleukin (IL) -­2, interleukin (IL) -­4, interleukin (IL) -­6, interleukin (IL) -­‐10, interleukin (IL) -­17, tumor necrosis factor (TNF)-­α, interferon (IFN)-­γ and macrophage migration inhibitory factor (MIF). We also evaluated blood transfusion and eight morbidity related variables: CPB time, aortic cross-­clamping time, inotropic score, cumulative TISS score, oxygenation index, volume of postoperative bleeding in the first 48 hours, duration of mechanical ventilation and length of stay in intensive care unit (ICU) postoperatively. Considering the kinetics of the concentrations of the cytokines evaluated, the concentrations of IL-­6, IL-­10 and MIF significantly changed in response to the surgical procedure. The concentrations of IL-­‐6 increased in T3, T4 and T5 and returned to baseline values at T6. The concentrations of IL-­10 increased in T2, T3 and T4 and returned to baseline values at T5. Concentrations of MIF increased in T2 and T3, returned to baseline in T4 and rose again at T6. Red blood cell transfusion had no impact on plasma concentrations of IL-­6, IL-­10 and MIF. Plasma concentrations of IL-­2, IL-­4, IL-­17, IFN-­γ and TNF-­α did not change significantly since the induction of anesthesia to the second postoperative day. Regarding the correlation of the concentrations of cytokines with morbidity in the postoperative period, we detected a positive correlation between plasma concentrations of IL-­6 and inotropic score. Different from what occurred with IL-­6, there were no correlations between the concentrations of IL-­10 and MIF and inotropic score. We did not found any correlation among the concentrations of IL-­6, IL-­10 and MIF and the following variables: CPB time, aortic cross-­clamping time, cumulative TISS score, oxygenation index, volume of postoperative bleeding in the first 48 hours, duration of mechanical ventilation and ICU length of stay. Therefore, for this group of patients, characterized as low risk, we have found a significant elevation of plasma concentrations of the mediators IL-­6, IL-­10 and MIF in response to corrective surgery. Packed red blood cells transfusion had no impact on plasma concentrations of these mediators. Also, no correlation was found between elevated concentrations of these mediators and the majority of morbidity related perioperative and postoperative variables that were evaluated.