Changes And Significance Of Bispectral Index In Children Undergoing Repair Of Ventricular Septal Defect During Endotracheal Intubation Under IV Anesthetic Induction And Cardiopulmonary Bypass

Background The repair of ventricular septal defect of children is performed under intracardiac operation underdirect vision.It requires stabilization of haemodynamics,and anesthetists easily misestimate patient's depth of hypnosis during cardiopulmonary bypass(CPB)and hypothermia.All of these elements could lead to administration of inappropriately high or low doses hypnosics.It is not profit to patient's recovery that either incidence of intraoperative awareness or overdeep state of anesthesia,untable haemodynamic status and prolonged recovery. Bispectral Indxe(BIS)has been validated as a measure of anesthetic-induced sedation and hypnosis in adult patients.It reduced the incidence of intraoperative awareness.Compared to adults,it needs further research of estimation of anesthetic depth because of children's brain immaturation.To children's intracardiac operation underdirect vision particularly,the estimation of depth of hypnosis is not clear.Objective The purpose of this study is to observe the changes of bispectral index and relative factors in children undergoing repair of ventricular septal defect during endotracheal intubation underⅣanesthetic induction and cardiopulmonary bypass.Methods Thirty children of either sex(17 male,13 female),ASA physical statusⅠ～Ⅱ,aged 3～6 yr,weighing(10～20kg)was scheduled to elective repair of ventricular septal defect.Children having cardiovascular,major vascular or neurosurgical procedures were excluded,as were those with large anticipated fluid shifts or body temperature changes.Patients were also excluded if they had significant cardiovascular,respiratory,or neurologic disease or if they were taking chronic medications known to affect the EEG.Routine monitoring of vital signs(comprising electrocardiography,radial artery blood pressure, pulse oximetry,and heart rate)was supplemented.A disposable pediatric BIS adhesive sensor was placed on each child's forehead and connected to a BIS monitor(A-2000XP BIS Monitor;Aspect Medical Systems).All children were premedicated with oral midazolam(0.5mg/kg).After thirty minutes and UMSS scores is 1～2point,children were transferred to operating room.Nasopharyngeal temperature(NPT)was meansured. Peripheral intravenous cannulas were inserted under local anaesthesia. After breathing 100%oxygen for three minutes through a facemask, anaesthesia was induced with intravenous midazolam 0.1mg/kg, sulfentanyl 0.15ug/kg,vecuronium 0.15mg/kg,etomidate 0.3mg/kg, rocuronium,the tracheal was intubated and ventilated.The anesthesia was maintained with continuous infusion of 8～10mg·kg^-1·h^-1propofol, 8～2.0ug·kg^-1·h^-1sulfentanyl and 1.5mg·kg^-1·h^-1vecuronium until temination of CPB.Datas were recorded during endotracheal intubation and CPB.The SPSS software 15.0 was used for data analysis.Data are presented as mean±SD.BIS,MAR HR,NPT were analyzed by means of repeated-measures,near correlation and multiple linear regression analysis of variance.Statistical significance was defined as P＜0.05.Results HR,MAP and BIS after endotracheal intubation were higher than before tracheal intubation and lower than before induction(P＜0.05). After CPB and cross clamping of the ascending thoracic aorta,MAP, NPT and BIS descended(P＜0.05).After declamping of the ascending thoracic aorta,NPT and BIS ascended(P＜0.01).Changes of MAP and NPT have linear correlation with BIS,the correlation of NPT and BIS was tighter than that of MAP and NPT.Conclusion 1.To children with ventricular septal defect, endotracheal intubation underⅣanesthesia may lead to ascendance of MAP and BIS.2.Along with descending of NPT and MAP,BIS descends after CPB and cross clamping of the ascending thoracic aorta.Along with ascending of NPT and MAP,BIS ascends after declamping of the ascending thoracic aorta.During CPB,changes of MAP and NPT have positive correlation with that of BIS,correlation of NPT and BIS is tighter than that of MAP and NPT.