Effect Of Different Ventilation Model On Lung Ventilation Function In Patients Undergoing Laparoscopic Radical Gastrectomy Based On Lung Ultrasound Score

Objective:To investigate the effects of pressure-controlled volume guaranteed（PCV-VG）mode and volume control（VCV）mode based on lung ultrasound score（LUS）on ventilation function and pulmonary complications in patients undergoing laparoscopic radical gastrectomyMethods:80 patients with elective laparoscopic radical gastrectomy,male 67 cases and female 13 cases,aged 45～75 years,ASA grade I to III,were randomly divided into two groups:the VCV group and the PCV-VG group,with 40 cases in each group.All patients underwent routine anesthesia induction.A lung protective ventilation strategy was adopted,with V_T 7ml/kg,positive end-expiratory pressure of 5cm H₂O and Fi O₂ 40%.Volume-controlled ventilation mode was adopted in the VCV group and pressure-controlled volume guaranteed ventilation mode was adopted in the PCV-VG group.Bedside pulmonary ultrasound was used to evaluate the LUS in 12 areas of bilateral lungs.Record the LUS when entering the room（T₀）,20min（T₁）after anesthesia induction endotracheal intubation,30min（T₂）after the establishment of artificial pneumoperitoneum,15min（T₅）after extubation of endotracheal tube,and record Pa O₂ and Pa CO₂ by blood gas analysis.The peak airway pressure（Ppeak）,plateau airway pressure（Pplat）,mean airway pressure（Pmean）,dynamic lung compliance（Cdyn）,and V_T of T₁,T₂,T₃（1h after pneumoperitoneum）,and T₄（at the end of the operation）were recorded.Record HR and MAP at T₀～T₅.The incidence of pulmonary complications（PPCs）within 3 and 7 days after operation was recorded.Results:the demographic data showed that there was no significant difference between the two groups.Compared with T₀,The LUS of the whole and partial areas（posterior side,lower side and right lung）in the VCV group was lower at T₂ and the LUS of the whole whole and partial areas（lateral side,lower side and left lung）in the VCV group was significantly higher at T₅ than that at T₀（P<0.05）;the LUS of the whole and each region in the PCV-VG group was lower at T₁,T₂,T₅than that at T₀（P<0.05）.Compared with the VCV group,the overall and regional LUS of the PCV-VG group were lower at T₁,T₂,T₅（P<0.05）.Pa O₂ at T₁,T₂,T₅ in the PCV-VG group was significantly higher than that in the VCV group（P<0.05）.Pa CO₂ at T₁ and T₅ was lower than that in the VCV group,the difference was statistically significant（P<0.05）.From T₁ to T₄,Ppeak in PCV-VG group was significantly lower than that in VCV group,Pmean and Cdyn were significantly higher than that in VCV group.The Pplat at T₄ group was significantly lower than that in VCV group（P<0.05）.The pulmonary complications within 3 days after operation in the PCV-VG group were lower than those in the VCV group[11 patients（27.5%）vs 4 patients（10%）,P<0.05].Conclusion:LUS in the VCV mode and PCV-VG mode can show the heterogeneity and positional changes of pulmonary ventilation during operation.The PCV-VG mode under the lung-protective ventilation strategy significantly improved the intraoperative lung ventilation and oxygenation function of patients undergoing laparoscopic radical gastrectomy,it is more beneficial to patients undergoing laparoscopic radical gastrectomy.