Effect Of Desflurane Post-conditioning On Myocardial Protection In Patients Undergoing Cardiac Surgery Under Cardiopulmonary Bypass

Objective:To observe and evaluate the protective effect of desflurane post-conditioning on myocardial injury during cardio-pulmonary bypass and its influence on patients’postoperative recovery.Methods:A total of 40 patients in need of cardiac surgery were selected as the experimental subjects,who were aged from 20 to 65 years old,and divided into ASA II-III and NYHA II-III by endotracheal intubation and extracorporeal circulation method under general anesthesia.The patients were randomly divided into desflurane post-treatment group（experimental group,roup D）and control group（group C）after selection.With the successive opening of the aorta and superior vena cava,group D were given 5%desflurane by inhalation with mechanical ventilation.Meanwhile,the concentration of PET desflurane was monitored in real time allowing to regulate the inhaled concentration and maintain the PETdes at 1 MAC.The total inhalation time was 10 minutes.While group C inhaled pure oxygen without inhaling desflurane,with the flow rate of 6L/min,and the total inhalation time of 10 min.The depth of intraoperative anesthesia was maintained between 40-50 during the operation.Radial artery blood was collected from patients in multiple time periods,including 24 h before surgery（T₀）,immediately after intubation（T₁）,and1 h（T₂）,6 h（T₃）,and 12 h（T₄）and 24 h（T₅）after aortic opening to achieve the determination of troponin I（cTnⅠ）and creatine kinase isoenzyme MB（CK-MB）.Besides,the right atrial appendage tissue needed to be collected for achieving the determination of cell apoptosis rate,with the collection time before aortic intubation(T_1.5)and 1 h after aorta opening（T₂）.Finally,the relevant clinical time information of patients were recorded,including the clinical conditions of CPB time,aortic occlusion time,mechanical ventilation time,length of stay in ICU and hospitalization,as well as the volume of drainage and urination on the right postoperative day（POD₀）,the first postoperative day（POD₁）,the second postoperative day（POD₂）and the third postoperative day（POD₃）.Results:1.There was no significant difference in the basic data between the two groups（P>0.05）.2.Comparison of cTnⅠ:cTnⅠ in group C at the time of T₂,T₃and T₄was apparently higher than group D,the difference was statistically significant（P<0.05）.3.Comparison of CK-MB:CK-MB in group C at the time of T₃was apparently higher than group D,the difference was statistically significant（P<0.05）.4.The myocardial tissue results showed that there was no statistical significance between the two groups on the apoptosis rate at the time of T_1.5（P=0.917）.There was a lower apoptosis rate in experimental group at the time of T₂,the difference was statistically significant（P<0.05）.5.The difference in clinical data was statistically significant（P<0.05）,because the experimental group had all the time data related to the cardiopulmonary bypass,mechanical ventilation,length of stay in ICU and hospitalization,which was much lower than that of control group.6.Clinical data:The volume of urine and drainage in POD₀,POD₁,POD₂ and POD₃ of the two groups tended to change with time（P<0.05）,but there were no difference in the two groups（P>0.05）.Conclusions:Desflurane post-conditioning has a myocardial protec-tive effect during cardiac surgery under cardiopulmonary bypass.