A clinical study on the association between lactic acid level and dorsal ventilation distribution in EIT in patients complicated with ARDS after acute brain injury
WANG Huan
ZHENG Xin
ZHONG Ming
Abstract：Objective To study the correlation of arterial blood gas-related indicators with dorsal lung venti-lation and abnormal pulmonary blood flow in acute brain injury(ABI)patients complicated with acute respiratory distress syndrome(ARDS)by using electrical impedance tomography(EIT).Methods The data of pulmonary ventilation and pulmonary blood flow monitored by EIT in 12 patients complicated with ARDS after ABI who were admitted to the Depart-ment of Intensive Care Medicine of Zhongshan Hospital of Fudan University from May 2020 to December 2021,and the patients'arterial blood gas and inflammation-related clinical indicators during this period were collected.According to the sum of the patients'dorsal ventilation regions of interest(ROI)(ROI3+ROI4),they were divided into low level of dorsal ventilation group(n=6)and high level of dorsal ventilation group(n=6)with median as the boundary.According to the level of partial pressure of carbon dioxide in artery(PaCO2),the patients were divided into PaCO2 hypoventilation group(n=6)and PaCO2 hyperventilation group(n=6)with the median as the boundary point.A correlation analysis was performed between the sum of the patients'dorsal ventilation ROI and lactic acid and other indicators,and the patient's dead space,shunt fraction,and ventilation-perfusion matching level under EIT were calculated.Results In the patients complicated with ARDS after ABI,a negative correlation was found between the sum of EIT dorsal ventilation(ROI3+ROI4)and lactic acid level in arterial blood(r=-0.700,P=0.011).The were no significant differences in arterial blood gas indicators and inflammation-related indicators between the low level of dorsal ventilation group and the high level of dorsal ventilation group(P＞0.05).There were no significant differences in arterial blood gas indicators and inflammation-related indicators between the PaCO2 hypoventilation group and the PaCO2 hyperventilation group(P＞0.05).According to the available EIT pulmonary ventilation and perfusion imaging data from 5 cases,the patients'average level of ventilation-perfusion matching was(49±11)％(＜60％),indicating that there was a significant mis-match in pulmonary ventilation-perfusion.Conclusion In the patients complicated with ARDS after ABI,there is a significant imbalance in ventilation-perfusion matching in them,and detection of lactic acid level in arterial blood can be used to monitor the status of dorsal ventilation.
Keywords：Electrical impedance tomographyAcute brain injury(ABI)Acute respiratory distress syndrome(ARDS)Lactic acid
Publication Date：2024-02-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 145-150 )