Clinical Study Of Small Tidal Volume Combined With Individualized Positive End Expiratory Pressure On Pulmonary Function And Pulmonary Complications In Patients Undergoing Thoracoscopic Surgery

Objective:This study compared the intraoperative oxygenation,circulatory function,incidence of postoperative pulmonary complications（PPCs）,postoperative pulmonary function,and recovery status in patients undergoing thoracoscopic surgery who received small tidal volume（STV）combined with positive end expiratory pressure（PEEP）or STV mode only.In order to find a more favorable pulmonary protective ventilation anesthesia management plan,reduce PPCs,and accelerate postoperative recovery of patients.Methods:From August 2021 to December 2021,60 patients who were scheduled to undergo thoracoscopic surgery were recruited from The First Hospital of China Medical University.The patients were randomly divided into a small tidal volume group（S group）and a small tidal volume+PEEP group（SP group）using a random number table,with 30patients in each group.The tidal volume of Group S is set at 6-8ml/kg ideal body weight,with PEEP=0 cm H2O;The tidal volume of SP group is set at 6-8ml/kg ideal body weight,and PEEP is the lowest inflection point of the pressure volume（P-V）curve+2 cm H₂O.Record the general condition,blood gas analysis results,and hemodynamic indicators of the patient at the beginning of single lung ventilation（OLV）,30 minutes after starting OLV（T2）,and 5 minutes before extubation（T3）.Follow up the incidence of pulmonary complications,pulmonary function,and recovery of patients after surgery.Results:There was no statistically significant difference in the general information of patients,including gender,age,height,weight,and ASA grading between the two groups（P>0.05）;The incidence of PPCs in SP group was lower than that in S group（P=0.042）;There was no significant difference in preoperative lung function between the two groups of patients.On the 5th day after surgery,there was a slight decrease in lung function in the SP group,but there was no statistically significant difference compared to the S group（P>0.05）;There was no significant difference in the arterial blood partial pressure of carbon dioxide（Pa CO2）and heart rate（HR）between the two groups at three times（P>0.05）.At T1,there was no significant difference in oxygenation index（OI）and mean arterial pressure（MAP）between the two groups of patients（P>0.05）.At T2 and T3,the oxygenation index of S group was lower than that of SP group（P<0.008 and<0.001,respectively）,while MAP was higher than that of SP group（P<0.001 and<0.001,respectively）;Compared with the S group,the postoperative hospitalization days of patients in the SP group decreased（P=0.001）and the time to get out of bed was earlier（P=0.023）.There was no significant difference in postoperative thoracic tube retention time between the two groups（P>0.05）.Conclusion:For patients undergoing thoracoscopic surgery,SVT combined with personalized PEEP ventilation strategy can effectively reduce the occurrence of PPCs and improve intraoperative oxygenation function compared to SVT ventilation alone.Meanwhile,the use of SVT combined with personalized PEEP can promote early recovery in patients.