The Influence On The Change Trend Of Stress And Myocardial Injury Produced By Different Sedation After The Open Heart Surgery Of Infants

Objective:Congenital heart disease(CHD)is the most common infant birth defects,the incidence rate is 6‰~8‰.Infant cardiac surgery have a higher risk rate.and the lower age groups have the higher incidence of mortality and complications.A series of stress generated by anesthesia、cardiopulmonary bypass、pain and so on, not only exist during the surgery,but also in a certain period after the operation. Data have shown that too strong stress response will lead to metabolic and homeostasis disorders. More severe cases will get stress disease. In the early time of chijdren return ICU after cardiopulmonary bypass,each organ system is still in the adaptation, adjustment and recovery phase.In actual work, hemodynamic changes after corrective surgery, mechanical ventilation status,metabolism imbalance within the electrolyte and acid-base homeostasis damage rebalancing and many other issues have affected especially the younger infants with congenital heart disease which the heart function was in recoving after surgery.Stress response is a kind of non-specific reactions of the body under the action of a series of stimuli by neuroendocrine and immune system. It is a complex physiological process.Suitable stress response to maintain homeo- stasis and homeostasis,but too strong stimulate lead to metabolic and the internal environment disorder.All about anesthesia, pain,non-physiolo- gical perfusion under the cardiopulmo-nary bypass,low temperature,blood and foreign body surface contact and hemodynamic changes will cause the body to produce a strong reaction. This results in widespread and severe effects on the body.During surgery and cardiopulmonary bypass,stress can activate two major axes or physiological pathways.That is sympathetic adrenal system and the hypothalamic-pituitary-adrenal axis.Blood glucose,plasma catecholamine and hemodynamic changes are reflected the body’s stress response sensltive and specific.This study was to understand the changing trends of blood glucose,cortisol after the cardiopulmonary bypass surgery,in order to underst- and the postoperative myocardial injury and the changing trend of heart, researchers the relationship between stress and myocardial injury and heart function.All above,we expect to take effective measures to reduce infant mortality and the incidence of complications as soon as possible, especially in low age and low birth weight children.In order to promote postoperative recovery course smoothly.Method:From 2012 February to 2013 October,we chose76 children with congenital heart disease age from 4 months to 3 years old, were randomly divided into experimental group(T)and control group(D). Inclusion criteria:(1) single disease(ventricular septal defect),except with other cardiac malfor- mations,pulmonary arterial hypertension, infection diseases and genetic metabolic diseases;(2) all are complete intracardiac malformation correction surgery under the cardiopulmonary bypass;(3)age from 4 months to 3 years;(4) except the preoperative fasting blood glucose abnormalities, hypoxic episodes, preoperative within 48 hours of continuous or repeated application of sedative drugs, Down’s syndrome, with disease infection, respiratory failure, heart failure, coma, cardiopulmonary resuscitation(CPR) etc.;(5)except for operation after the defect residual leakage and postoperative degrees above the valve regurgitation. All these children would go into the CICU after cardiopulmonary bypass. The T group give continuous intravenous infusion of dexmedetomidine(0.4-0.7ug.kg-1.h-1) and the D group give midazolam(1~2ug.kg-1.min)with the same way for sedation and analgesia. Record the heart rate,blood pressure, saturation of blood oxygen,arterial oxygen partial pressure and arterial partial pressure of carbon dioxide of the two groups after operation 1h、4h、12h、24h and 48 h. At the same time,we also record wake-up time.The record would be stop after the sedative and analgesic drug had been stoped for 12 hous. According to the scoring system for sedation and analgesia to record the scores by professional persons.To detect stress index(blood glucose, cortisol)and cardiac function, myocardial damage markers(BNP, c Tn I) respectively after 1h(t1)、4h(t2)、12h(t3)、24h(t4)、48h(t5) in venous.Results between the two groups were compared using the paired T test, intra group comparisons using repeated measures analysis of variance. The correlation between the index of stress and myocardial injury adopted multiple regression analysis.Results: 2h pre-operation and 1h, 4h, 12 h, 24 h, 48 h after operation.1 Four parameters were significantly higher than that before operation in 48 h after operation. The difference was statistically significant.2 BNP、c Tn I:The two indexes have reached the peak at t1 and t group were significantly lower than those of D group, the difference was statistically significant(P<0.05).3 Glu、Cor:Two groups of Glu were reached the peak at t2, while the two groups of Cor were reached the peak at t1 when they were detected. And the level of T group were lower than the D group, the difference was statistically significant(P<0.05).4 Glu and Cor’s level was able to affect the level of c Tn I and BNP, but no significant correlation with their change trend.5 By two different ways of sedation and analgesia,the T group’s Glu and Cor levels were significantly lower than that in D group,the difference was statistically significant(P<0.05).Conclusions:After the open heart surgery in cardiopulmonary bypass, infants can occur with different abnormal hemodynamics and different properties of neurohumoral abnormalities. And the stress reaction caused by will not conducive to the recovery of myocardial injury and the heart function.The postoperative effects of dexmedetomidine continuous sedation and analgesia in children after operation can significantly reduce discomfort, anxiety and the stress reaction degree.Do like this, we can significantly reduce the stress reaction degree and conducive to the maintenance of stable hemodynamics.It also can promote the recovery of heart function and myocardial damage and reduce the incidence of related complications.