Effect Of Spontaneous Breathing On Atelectasis During Induction Of General Anesthesia In Patients Undergoing Laparoscopic Resection Of Gastrointestinal Tumors

Objective:To explore the effect of spontaneous breathing during induction of general anesthesia on atelectasis in patients undergoing laparoscopic resection of gastrointestinal tumors.Methods:Sixty patients scheduled for laparoscopic resection of gastrointestinal tumors under general anesthesia in the First Hospital of Shanxi Medical University from October 2021to August 2022 were selected.All patients were divided into two groups using a random number table methods(n=30):‘spontaneous’group(Group S)and‘controlled’group(Group C).In group S,0.2～0.3mg/kg etomidate(pumping at the speed of 200ml/h)and2ug/kg remifentanil were used for anesthesia induction;In group C,0.2～0.3mg/kg etomidate,2ug/kg remifentanil and 0.2mg/kg cisatracurium were used.After BIS decreased to 80 and the patient lost consciousness,the mask was used in group S to closely fit the face and maintain spontaneous breathing;Group C received manual positive pressure ventilation.Pulmonary atelectasis score was recorded using ultrasound immediately after endotracheal intubation(T1)and 15 minutes after transporting to the recovery room(T3).Collecting arterial blood for blood gas analysis and calculating oxygenation index(OI)5 minutes after tracheal intubation(T2)and T3.The occurrence of postoperative pulmonary complications(PPCs)on the third day after operation was recorded.Results:Compared with group C,the pulmonary atelectasis score of group S at T1 and T3decreased[(2.4±0.8)vs(4.2±0.7)](t=-9.12,P<0.001)&[(8.2±1.8)vs(10.5±1.6)](t=-4.96,P<0.001),and the OI increased at T2 and T3[(334±11)mm Hg vs(323±13)mm Hg](t=3.45,P=0.001)&[(362±23)mm Hg vs(347±25)mm Hg](t=2.31,P=0.025).The incidence of PPCs was 21%(6/29)and 19%(5/27)respectively in group C and group S on the third day after operation,with no statistical difference(X~2=0.04,P=0.838).Conclusion:Maintaining spontaneous respiration during induction of general anesthesia can reduce atelectasis caused by general anesthesia and improve oxygenation in patients undergoing laparoscopic resection of gastrointestinal tumors.