Application Of Different Pressure Lung Ventilation In The Operation Of Elderly Patients Under Laryngeal Mask General Anesthesia

Objective:To observe the application of laryngeal mask combined with different pressure pulmonary reexpansion lung protective ventilation strategy in general anesthesia operation for the elderly population and whether it can lower the incidence of postoperative pulmonary complications in these kinds of patients.Methods:The patients who met the conditions of the study were selected.(1)In the first experiment,the application of different pressure lung ventilation in the general anesthesia of laryngeal mask in the orthopedic operation of the elderly:the subjects were randomly divided into two groups: the traditional ventilation group(LH group)and the individualized pressure lung ventilation group(LP1group,20cmH2 O and LP2 group,30cmH2O).To compare the hemodynamic indexes of the patients in each group during the perioperative period,the changes of blood gas analysis results before and after the operation(T1 as the basic value),one hour interval between the operations(T2)and the end of the operation(T3),the completion of laryngeal mask combined with differentpressure pulmonary reexpansion protective ventilation strategy in the elderly patients during the whole body anesthesia operation,the pulmonary complications after the operation,the insertion and removal of laryngeal mask Time and patient satisfaction.(2)In the second experiment,we compared the hemodynamic indexes,the blood gas analysis results of T1(as the basic value),T2(one hour interval)and T3(end of operation)before operation,the completion of laryngeal mask combined with different pressure pulmonary protective ventilation strategies in the general anesthesia operation of the elderly patients,and the pulmonary complications after operation,the condition of inserting and pulling out laryngeal mask and the satisfaction of patients.At the same time,the interaction between BIS monitoring,analgesic use,target controlled infusion of propofol and lung protective ventilation strategy was observed.Results:(1)Experiment 1: the application of different pressure pulmonary ventilation in the elderly orthopaedic surgery under laryngeal mask general anesthesia.At the beginning of this study,144 patients(all orthopedic operations are limb joint operations,no orthopedic operations involving spine)were included.According to the inclusion and exclusion criteria,20 patients were excluded,including 10 patients whose operation time is more than five hours,3 patients whose bleeding volume is more than 20% of blood volume,2patients who need secondary operation,3 patients who need blood products infusion,2 patients who need vasoactive drug maintenance,41,42,41 patients were included in LH group,Lp1 group,LP2 group.It was shown no differentmeanings in general condition(age,gender,weight,preoperative lung,etc.)and general condition during operation among the three groups.It was shown no difference in the changing of heart rate and blood pressure in the three groups.The results of arterial blood gas analysis at T1-T3 time point showed that the blood gas of LP1 group and LP2 group was better than that of LH group,while the difference between LP1 group and LP2 group was not statistically significant.In terms of postoperative complications,LP1 group and LP2 group had better prognosis than LH group,but there was no significant difference between LP1 group and LP2 group.There were 16 cases of PPCs in the whole study cohort.By statistical test,the incidence of patients in LP group was lower than that in LH group,but there was no significant difference between Lp1 group and LP2 group.In LP1 group,the target value of RM was20 cmH2 O,39of 42 patients reached the target value,while in LP2 group,the target value of RM was 30 cmH2 O,but only 31 of 41 patients reached the target value,LP1 group was significantly better than LP2 group;(2)experiment 2,the application of different pressure lung expansion in laryngeal mask general anesthesia in elderly gynecology operation.134 patients(all gynecological operations were laparoscopic gynecological operations,not involving traditional open surgery)were included in the initial stage of this study.According to the inclusion and exclusion criteria,8 patients were excluded,including 4 patients with operation time more than five hours,1patient with bleeding volume more than 20% of blood volume,2 patients who needed secondary operation,1 patient who needed blood products infusion,LP1 group,LP1 group,LP2 group were included in 42,41,43 patients,respectively.It was shown no different meanings in general condition(age,weight,preoperative lung,etc.),intraoperative fluid input and discharge,bleeding volume,etc.It was shown no difference in the changing of heart rate and blood pressure in the three groups.The results of T1-T3 time point arterial blood gas analysis showed that the blood gas situation of LP1 group and LP2 group was better than that of LH group in operation and after operation,but there was no significant difference between LP1 group and LP2 group.In terms of postoperative complications,LP1 group and LP2 group were better than LH group in terms of prognosis,but there was no significant difference between Lp1 group and LP2 group in terms of prognosis.PPCs occurred in 14 cases in the whole study cohort.The incidence of PPCs in LP group was lower than that in LH group.The incidence of PPCs in LP1 group was slightly lower than that in LP2 group.In LP1 group,the target value of RM was 20 cmH2 O,36 of 41 patients reached the target value,while in LP2 group,the target value of RM was 30 cmH2 O,only 25 of 43 patients reached the target value.Meanwhile,BIS monitoring shows that the use of lung protective ventilation strategy can enhance the anesthesia stability during general anesthesia.TCI target controlled infusion combined with BIS monitoring can reduce the use of anesthesia drugs in perioperative period,and the recovery time is shorter.Conclusion:The lung protective ventilation strategy of 20 cmH2 O in laryngeal mask general anesthesia is easy to implement in the operation of elderlypatients.The lung protective ventilation strategy of 20 cmH2 O in laryngeal mask general anesthesia is better in the operation of elderly patients.