The Effects Of Different Mechanical Ventilation Modes On Perioperative Lung Function In Patients Undergoing Gynecological Laparoscopic Surgery

Objective To investigate the effects of different ventilation modes on perioperative lung function of patients undergoing gynecological laparoscopic surgery,and to investigate whether protective pulmonary ventilation strategies can better adapt to the changes of respiratory mechanics during gynecological laparoscopic surgery,so as to reduce the incidence of lung injury.Methods From March 2017 to March 2019,180 patients who underwent elective gynecological laparoscopic surgery were randomly divided into three groups by computer random number method:volume controlled ventilation mode group（V group）,pressure controlled ventilation mode group（P group）and protective pulmonary ventilation strategy group（VPR group）.Volume-controlled ventilation mode group（tidal volume VT 8～12ml/kg,absorption ratio（I:E）=1:2）;Pressure-controlled ventilation mode group（set the inspiratory pressure range as10～35cm H₂O and the maximum not exceeding 40cm H₂O,so that the tidal volume reaches VT8～12ml/kg,I:E=1:2）;Lung protective ventilation strategy group（tidal volume 6ml/kg+manual lung retraction（RM）+Expiratory positive pressure ventilation（PEEP）was set as 5cm H₂O）.After intravenous induction of tracheal intubation under general anesthesia,the three groups maintained end-expiratory carbon dioxide(P_ETCO₂)of 35～45 mm Hg by adjusting ventilation parameters.Record into the group of patients with tracheal intubation after 5 min before pneumoperitoneum（T₁）,30 min after pneumoperitoneum start（T₂）,10 min after pneumoperitoneum（T₃）of heart rate（HR）,mean arterial pressure（MAP）,the Airway peak pressure(Airway peak pressure,P_peak),platform of Airway pressure,Airway platform pressure,P_plat),arterial blood gas analysis（Pa O₂,Pa CO₂）;And calculate the Dynamic lung compliance(Dynamic lung cdyniance,C_dyn)and inspiratory resistance（Airway hold,Raw）,Oxygenation index（Oxygenation index,OI）,alveolar artery blood oxygen partial pressure difference（A-a DO₂）,Respiratory index（Respiratory index,RI）;Bedside pulmonary ultrasound assessment scheme（BLUE）was used to detect the ultrasonic images of the lungs of patients before induction of anesthesia（T₀）and 15min（T₄）after tracheal extubation,and the incidence of atelectasis was assessed by LUS scoring standard.Results 1.At T₁,P_peakin group V was significantly higher than that in group P and VPR;at T₂,P_peakin group V was significantly higher than that in group P and VPR;at T₃,P_peakin group V was close to T₁,but still higher than that in group V（P<0.05）.Compared with T₁,P_platwas significantly increased in the three groups at T₂,and was significantly higher in the V group than in the P group and the VPR group（P<0.05）.In T₁to T₃,Raw of P group and VPR group were lower than that of V group（P<0.05）.T₁and T₃time Cdyn in P group and VPR group were significantly higher than that in V group（P<0.05）.2.In T₂time,Pa O₂of P group and VPR group was significantly higher than that of V group（P<0.05）,and that of VPR group was higher than that of P group,but the difference was not statistically significant;in T₂time,Pa CO₂of P group was lower than that of V group and VPR group（P<0.05）.3.A-a DO₂in three groups increased significantly compared with T₁at T₂（P<0.05）,and decreased nearly to T₁level at T₃;OI in three groups decreased significantly compared with T₁at T₂（P<0.05）,and group V was significantly lower than group P and VPR（P<0.05）;RI in three groups increased compared with T₁at T₂,and decreased nearly to T₁level at T₃compared with T₂,but there was no significant difference between groups at three time points.4.There was atelectasis in all three groups,VPR group was less than the other two groups,and the LUS score of VPR group was significantly lower than that of P group and V group（P<0.05）.Conclusion In gynecologic laparoscopic surgery,compared with volume controlled ventilation and pressure controlled ventilation,lung protective ventilation strategy is more conducive to improving patients’oxygenation function and reducing the incidence of atelectasis.