Determination of individualized PEEP during lung-protective ventilation in patients undergoing general anesthesia: comparison of pulmonary electrical impedance tomography and dynamic lung compliance / 中华麻醉学杂志

ABSTRACT

Objective:To compare the efficacy of individualized PEEP determined by lung electrical impedance tomography (EIT) and dynamic lung compliance (Cdyn) during lung-protective ventilation strategies in the patients undergoing general anesthesia.Methods:Sixty patients of both sexes, aged 18-64 yr, of American Society of Anesthesiologists physical status Ⅰor Ⅱ, with body mass index of 18.5-28.0 kg/m 2, undergoing elective surgery with general anesthesia and endotracheal intubation in the Second Affiliated Hospital of Soochow University, were selected.Lung-protective ventilation strategy was applied in supine position after general anesthesia.The peak value of PEEP did not exceed 10 cmH 2O, with an increment/decrement of 2 cmH 2O for titration.The corresponding Cdyn value and lung EIT data were collected during titration.The patients were divided into 2 groups ( n=30 each) using a random number table method: titration first increased and then decreased group (group A) and titration first decreased and then increased group (group B). The determination method of individualized PEEP Cdyn method was the PEEP corresponding to the maximum Cdyn value; EIT method was obtained through PV500 PC software analysis.The level and success rate of individualized PEEP determined by the Cdyn and EIT methods were compared, and the ICC consistency analysis of the determined individualized PEEP was performed. Results:Compared with the Cdyn method, the success rate of individualized PEEP determined by EIT method was significantly increased, and the level of individualized PEEP was decreased in the two group ( P<0.05). In group A, the individualized PEEP titrated by the EIT and Cdyn methods showed good agreement (the ICC value of the increment-Cdyn and increment-EIT methods was 0.761, P<0.05; the ICC value of the decrement-Cdyn and decrement-EIT methods was 0.763, P<0.05). In group B, the individualized PEEP titrated by the EIT and Cdyn methods showed good agreement (the ICC value of the increment-Cdyn and increment-EIT methods was 0.809, P<0.05; the ICC value of the decrement-Cdyn and decrement-EIT methods was 0.797, P<0.05). Conclusion:The agreement between the individualized PEEP determined by lung EIT method and Cdyn method during lung-protective ventilation is good in the patients undergoing general anesthesia, and the success rate of EIT method is higher, and the level of individualized PEEP is lower.