Study Of The Optimization Of Anesthesia Effect Of Phrenic Nerve Block In Patients Undergoing Non-intubated Video-assisted Thoracoscopic Surgery

Objective:To avoid the risk associated with endotracheal intubation,non-intubation general anesthesia technology is increasingly used in thoracoscopic surgery.The purpose of this study is to explore and compare whether the phrenic nerve block combined with non-intubation general anesthesia has better anesthetic effect and can reduce the dosage of general anesthetics compared with the non-intubation general anesthesia at home and abroad.Methods:Eighty patients undergoing thoracoscopic lobectomy which use the non-intubation general anesthesia were randomly divided into control group（D group）and experimental group（S group）,40 patients in control group and 40 patients in experimental group.The control group and experimental group was treated with non-intubation general anesthesia combined with paravertebral nerve block,vagus nerve block and phrenic nerve block（the control group was treated with 0.9%saline for phrenic nerve block and the experimental group was treated with 2%lidocaine for phrenic nerve block）.The anesthesia was controlled by propofol dosage（BIS was controlled from 45 to 60）.The aim of anesthesia was that diaphragm swing did not affect the operation and patients could tolerate surgical stimulation.The primary outcome was intraoperative propofol dosage.The time of thoracotomy w as defined as T₁,the time of closing the chest was T₂,and the time of removing the laryngeal mask was T₃.The second outcomes include the arterial blood acidity and alkalinity（pH）,the lactic acid（LAC）,the systolic blood pressure（SBP）,the time of operation,the times of propofol bolus,the time of removing the laryngeal mask after operation,the time of hospitalization after the operation（from the day of operation to the time of discharge）,the cough function and dyspnea in 24 hours after operation and the pulmonary complications 30 days after operation.There was statistical difference at P<0.05.Results:There was significant difference in propofol dosage between group D and group S（t=10.36,P=0.000）,the mean was 57.20+4.12 ml and 49.20+8.73 ml,the mean difference was 8.00（95%CI:4.94,11.06）ml;there was no significant difference in SBP between the two groups（F=3.15,P=0.080）.There was no significant difference in SBP between group D and group S at T₁ and T₂,and there was significant difference in SBP between group D and group S at T₃（t=-3.52,P=0.001）,with the mean of 101.8±16.31 mmHg and 112.90±13.14 mmHg,respectively,with the mean difference of-11.10（95%CI:-17.69,-4.51）mmHg.There were significant differences in the mean of pH between the two groups（F=7.98,P=0.006）;there was no significant difference in the pH between group D and group S at T₁,T₂;there was significant difference in the pH between group D and group S at T₃（t=4.58,P=0.000）,the mean values were 7.33±0.02 and 7.30±0.03,respectively,with the mean difference being 0.03（95%CI:0.02,0.04）.There were significant differences in the mean LAC values between the two groups（F=12.31,P=0.001）.There was no significant difference between group D and group S of LAC at T₂,T₃.There was significant difference between group D and group S of LAC at T₁（t=-3.25,P=0.002）,the mean was 0.82±0.33mmol/L and 1.25±0.78mmol/L,respectively,and the mean difference was-0.44（95%CI:-0.71,-0.17）mmol/L.There was no significant difference in the time of removal of laryngeal mask between group D and group S（t=1.30,P=0.198）,the mean was 19.60+10.14 min and17.00+7.60 min.Respectively,the mean difference was 2.60（95%CI:-1.39,6.59）min.There was significant difference in the time of hospitalization after the operation between group D and group S（t=4.45,P=0.000）,the mean was 5.40±1.22 days and4.10±1.39 days,respectively,and the mean difference was 1.30（95%CI:0.72,1.88）days.There was no case of termination of the study due to mediastinal swing caused by surgical stimulation in both groups.The times of propofol bolus in group D was more than that in group S（Z=-3.127,P=0.002）.There was no significant difference in pulmonary air leakage between group D and group S（2=0.00,P=1.000）;there was no significant difference in subcutaneous emphysema between group D and group S（2=0.00,P=1.000）;there was no significant difference in pneumothorax between group D and group S（2=0.00,P=1.000）;no difficulty of cough or dyspnea occurred 24 hours after operation in both groups;there was no significant difference in atelectasis,pulmonary infection,respiratory failure and other pulmonary complications within 30days after operation between the two groups.Conclusions:Non-intubated general anesthesia combined with phrenic nerve block has optimized the anesthetic effect.There are no significant effect on circulation and significant effect on respiratory function during operation with phrenic nerve block combining with non-intubated general anesthesia.In the phrenic nerve block combined with non-intubation general anesthesia group,the time of hospitalization after the operation was shorter,no difficulty of cough or dyspnea occurred 24 hours after operation in both groups and the pulmonary complications had no significant difference at 30 days after operation,which indicated that phrenic nerve block accelerated the recovery of patients after operation and had no effect on patients’long-term pulmonary function.