Effect Of Individualized PEEP With Pulmonary Dynamic Compliance Titration On Pulmonary Protection And Postoperative Pulmonary Complications In Elderly Patients Undergoing Lumbar Surgery

Objective:Through using individualized positive end expiratory pressure（PEEP）titrated under the guidance of pulmonary dynamic compliance（Cdyn）for intraoperative mechanical ventilation on elderly patients undergoing lumbar spinal fusion in prone position,the final goal is to analyze the pulmonary protective effect of individualized PEEP（iPEEP）and its effect on postoperative pulmonary complications（PPCs）.Methods:From June 2019 to October 2020,70 patients with lumbar fusion in our hospital were enrolled in this study,including 36 males and 34 females,Age≥65,with an average age of 65.0±3.2 years,ASA physical status Ⅰ or Ⅱ.They were divided into the control group（n=35）and the observation group（n=3 5）randomly.Through implementation of lung protective ventilation,people in control group received PEEP with fixed 5 cmH2O level,while in observation group,after the prone position was placed,patients received individualized PEEP guided by Cdyn until the end of the operation.The corresponding PEEP value was taken as the iPEEP when obtaining the maximum Cdyn.Observation indicators:1.Hemodynamic fluctuation,respiratory dynamic parameters and arterial blood gas analysis values at different time points in the two groups;2.Changes of inflammatory response markers and lung injury markers at corresponding time points in the two groups;3.The occurrence of PPCs 7 days after operation in the two groups.Results:1.There was no significant difference between two groups in general condition and hemodynamic fluctuation at each time point（P>0.05）.The pulmonary driving pressure（DP）in observation group was significantly lower than that of control group and the oxygenation index（PaO2/FiO2）was significantly higher than that of control group in prone position for 35min and 95min,before the end of operation（P<0.05）.2.Compared with control group,IL-6 concentration and TNF-a concentration were significantly lower before the end of operation,1 day and 3 days after operation in observation group（P<0.05）.And before the end of operation,the concentration of CC-16 was significantly lower than that in control group（P<0.05）.3.The difference was statistically significant that there were 5.7%in observation group and 25.7%in control group combined with various types of pulmonary complications（P<0.05）.Conclusion:1.Individualized PEEP guided by Cdyn can reduce lung driving pressure and improve intraoperative oxygenation in elderly patients under lumbar fusion.2.Individualized PEEP guided by Cdyn can reduce the release of inflammatory mediators and reduce lung injury in elderly patients undergoing lumbar fusion surgery.3.Individualized PEEP guided by Cdyn can reduce the incidence of pulmonary complications after lumbar fusion in elderly patients.