The Feasibility Study Of The Proseal-LMA Applied In The MG Patients Undergoing Transsternal Thymectomy

【Objective】To observe and ascertain the safety and efficacy when Proseal-LMA was applied in the MG patients undergoing transsternal thymectomy.【Methods】The 60 patients for the selective transsternal thymectomy, ASAⅠ～Ⅱ, between 18 and 67 years of age, BMI<30kg/m2, excluding the serious heart or lung diseases, were randomly allocated to either Proseal-LMA group (Group P, n=30) or tracheal tube group (Group T, n=30). The anesthesia was induced and maintened by the total intravenous target-controlled infusion, using propofol for plasma target concentration, sufentanil for effect compartment target concentration. The anesthesia was performed without muscle relaxants in two groups. When the concentration of propofol reached to 4.0μg/ml and the concentrations of sufentanil reached to 0.44ng/ml, the patients in the group P were placed P-LMA with bare-hands, while the patients in the group T were inserted tracheal tube with laryngoscope after surface anesthesia of laryngopharynx and endotrachea, and all patients run in the IPPV mode. Just before the sternotomy, the propofol target concentration was made a up-regulation to 5.0μg/ml; after that, the sufentanil target concentration was made a down-regulation to 0.15ng/ml and the propofol target concentration keep 4～6μg/ml in order to maintain the anesthesia. Just before the closure of sternum, the sufentanil target concentration was made a down-regulation to 0.08ng/ml; after that, the propofol target concentration was made a down-regulation to 3.0μg/ml. Just before the skin suture, the infusion of propofol was shut down. In the course of the anesthesia, all datas—HR, MBP, Paw, SPO2> PetCO2 and BIS—were recorded according to four stages—induction, skin incision, sternotomy and extubation. Futher, the date that should be recorded also include the rate of bucking in extubation, the extubation rate in the operation room, the rate of intraoperative regurgitation, the rate of postoperative sore throat, the duration of operation, the duration of anesthesia, the duration from the end of skin suture to extabation and the rate of reintubation within 48 hours after the operation.【Results】There were no statistical differences in age, sex ratio, weight, BMI, MG types, ASA classification, operation duration, anesthesia duration and duration from the end of operation to extubation in two groups(P>0.05).①At the stage of intubation:compared with group T, the BIS levels in group P were significantly depressed at the time points—before intubation, just after intubation and 1 min after intubation(P<0.05).②At the stage of skin incision:compared with group T, the BIS levels in group P were significantly depressed at the time points—just after skin incision,1 min after skin incision and 3 min incision(P<0.05). The Paw in group P was higher than that in group T at just after skin incision (P<0.05). Compared with the group T, PETCO2in group P was obviously decreased at just after skin incision (P<0.05), and increased at the time point of 1 min after skin incision (P<0.05).③At the stage of sternotomy:compared with group T, the BIS in group P was significantly depressed at the time points—before sternotomy,1 min after sternotomy,2 min after sternotomy and 3 min after sternotomy(P<0.05). The Paw in group P was higher than that in group T at immediately after sternotomy (P<0.05). Compared with the group T, PETCO2 in group P was obviously decreased at immediately after sternotomy (P<0.05), and increased at the time point of 1 min after sternotomy (P<0.05).④At the stage of extubation:compared with group T, the MAP and the HR in group P was significantly decreased at immediately after extubation (P<0.05). At the same time the SPO2 in two groups was similar (P>0.05). Further, there were no statistical differences in the duration of operation, the duration of anesthesia, the duration from the end of skin suture to extabation between two groops. The extubation rate was 100% in two groups, the rate of intraoperative regurgitation was 0%, so were the reintubation rate within 48 hours after the operation.【Conclusion】The results suggest that Proseal-LMA can provide the same safe and effective ventilation as tracheal tube for the MG patients undergoing transsternal thymectomy. In the process of extubation, bucking occurrence rate is even more lower and vital signs are stable.