Comparison Of Lung Protective Ventilation Strategy In Different Ventilation Modes Under General Anesthesia In Laparoscopic Colorectal Surgery

?Objective?To investigate the effects of different ventilation modes on lung protective ventilation strategy compared with traditional ventilation strategies on respiratory mechanics,oxygenation and postoperative pulmonary complications in the laparoscopic surgery for colorectal cancer,providing the basis for the clinical mechanical ventilation.?Methods?The study included 36 patients aged 18 to 65,sex unlimited,ASA class ?^?,who were undergoing laparoscopic colorectal cancer surgery in Shenzhen No.2 People's Hospital from May 2017 to December 2017.Using the random number method dividedthe patients into traditional ventilation group?Group Traditional ventilation,n=12?,volume controlled ventilation group?Group VCV,n=12?and pressure controlled ventilation group?Group PCV,n=12?.The ventilation parameters of the traditional ventilation group were set to the tidal volume?Vt?10ml/kg and I/E 1:2.The ventilation parameters of Group VCV were set to Vt=6ml/kg,I:E=1:2,PEEP=6cmH₂O and recruitment maneuvers?stepwise increase of PEEP?at 10 minutes after the end of the pneumoperitoneum.In Group PCV,set inspiratory pressure to make Vt of 6ml/kg,PEEP=6cmH₂O,I/E 1:2,and recruitment maneuvers?stepwise increase of PEEP?at 10 minutes after the end of the pneumoperitoneum.In the operating room,standard monitoring was established.After anesthesia induction,the nasopharynx temperature,the end of the expiratory carbon dioxide(P_EtCO₂)and the arterial blood pressure of the radial artery were monitored.In the three groups,the fraction of inspired oxygen?FiO₂?was 50%,and the ventilation frequency?RR?was adjusted according to P_EtCO₂.The tidal volume was calculated based on the ideal body weight.Airway peak pressure?Ppeak?,airway plateau pressure?Pplat?,P_ETCO₂and dynamic lung compliance?Cdyn?were recorded at T1^T4.Blood gas analysis of radial artery blood was taken at T1^T4 to record arterial blood oxygen pressure?PaO₂?and arterial oxygen saturation.Driving pressure and dynamic lung cdyniance?Cdyn?,alveolar-arterial oxygen partial pressure difference?P?A-a?DO₂?,oxygenation index?OI?and respiratory index?RI?were calculated.The SpO₂of the first and third days after operation and the postoperative pulmonary complications within three days were observed and recorded.?Results?1.There was no significant difference in age,sex,BMI,operation time and smoking between the three groups?P>0.05?.2.Compared with T1,the Ppeak,Pplat and driving pressure in the three groups increased significantly during the pneumoperitoneum?T2?,and the Ppeak,Pplat and driving pressure in the PCV and VCV groups were lower than that in the traditional group.At T1 to T4,the Ppeak of PCV group was lower than that of VCV group and traditional group?P<0.05?.The driving pressure in group VCV and group PCV was lower than that in the traditional group?P<0.05?.3.Compared with T1,airway resistance increased in three groups at T2.At T1 to T4,the airway resistance of PCV group and VCV group were all lower than those of traditional group.At T2,the airway resistance of PCV group was lower than that of VCV group?P<0.05?.4.Compared with T1,the Cdyn of the three groups decreased at T2.After the end of the pneumoperitoneum,the Cdyn of the three groups recovered to T1 level?P>0.05?.Both VCV and PCV groups were significantly increased in T4?P<0.05?.When compared between groups,the Cdyn of group VCV and group PCV was significantly higher than that of traditional group at T4?P<0.05?,but there was no significant difference between VCV group and PCV group.5.Compared with before pneumoperitoneum?T1?,there was no significant difference in MAP and HR between the three groups at T2,T3 and T4?P>0.05?.There was no significant difference between the three groups.6.Compared with T1,the PaO₂of the three groups decreased at T2,and the VCV and PCV group increased significantly at T4?P<0.05?.After pneumoperitoneum?T2?and lung recruitment?T4?,the PaO₂in group PCV and group VCV were all higher than those in traditional group?P<0.05?.There was no significant difference in the contrast of SaO₂in the three groups,all in the normal range.At T4,the SaO₂of group PCV and VCV group was significantly higher than that of the traditional group.There was no significant difference between the PCV group and the VCV group.7.Compared with T1,the P?A-a?DO₂and RI of the three groups increased at the time of T2,while OI decreased.VCV and PCV in T4 group decreased and VCV increased in group VCV?P<0.05?.At the time of pneumoperitoneum?T2?,P?A-a?DO₂and RI in group PCV and VCV were lower than those in traditional group,and OI was higher than that in traditional group?P<0.05?.After lung recruitment?T4?,P?A-a?DO₂and RI in group PCV and VCV were all lower than those in traditional group,and OI was higher than that in traditional group.8.Compared with the day before the operation,SpO₂was decreased in the three groups and third days after the operation?P<0.05?.Third days after the operation,SpO₂was basically restored before operation in group VCV and PCV group,and the traditional group still decreased?P<0.05?on the day before operation.Between groups,the SpO₂in group VCV and group PCV was higher than that in traditional group on the first day and third day after operation.9.Therewasnosignificantdifferencebetweenintraoperative complications and postoperative pulmonary complications between the three groups.?Conclusion?1.In laparoscopic colorectal surgery,both the pressure controlled model and the volume controlled ventilation mode combined with the lung protective ventilation strategy can improve the arterial oxygenation and respiratory mechanics parameters and better pulse oxygen saturation can be obtained after the operation compared with the traditional ventilation strategy.2.Compared with the volume controlled ventilation mode combined with the lung protective ventilation strategy,the pressure control model combined with the lung protective ventilation strategy is more advantageous in controlling the airway peak pressure,which is suitable for the operation.