Ultrasound evaluation of cardiac and diaphragmatic function at different positions during a spontaneous breathing trial predicting extubation outcomes: a retrospective cohort study

Abstract

Abstract Background: The ratio (E/Ea) of mitral Doppler inflow velocity to annular tissue Doppler wave velocity by transthoracic echocardiography and diaphragmatic excursion (DE) by diaphragm ultrasound have been confirmed to predict extubation outcomes. However, few studies focused on the predicting value of E/Ea and DE at different positions, and the effects of △E/Ea and △DE [the changes of E/Ea and DE during a spontaneous breathing trial (SBT)]. Methods: This study was a reanalysis of the data of 60 difficult-to-wean patients in a previous study published in 2017. All eligible participants were divided into respiratory failure (RF) group and extubation success (ES) group within 48 hours, or re-intubation (RI) group and non-intubation (NI) group within 1 week. The risk factors for respiratory failure and re-intubation including E/Ea and △E/Ea, DE and△DE at different positions were analyzed by multivariate logistic regression, respectively. The receiver operating characteristic (ROC) curves of E/Ea (septal, lateral, average) and DE (right, left, average) were compared with each other. Combination of E/Ea and △E/Ea, or DE and △DE was analyzed to predict respiratory failure or re-intubation. Results: Among 60 patients, 29 cases developed respiratory failure, and 14 cases were re-intubated. Multivariate logistic regression showed that E/Ea were all associated with respiratory failure, while only DE (right) and DE (average) after SBT were related to re-intubation. There were no statistic differences between the ROC curves of E/Ea and DE at different positions. No statistical differences were shown in △E/Ea between RF and ES groups, but △DE (average) was remarkably higher in NI group than that in RI group. There was a tendency that the combined factor could predicted respiratory failure better than E/Ea (average) after SBT or △E/Ea (average) , same as for the combined factor predicting re-intubation better than DE (average) after SBT or △DE (average). Conclusions: Cardiac and diaphragmatic dysfunction were related topostextubation respiratory failure and re-intubation, respectively. There were no statistical differences in E/Ea at different positions, similarly with DE. The combined factors could show the highest diagnostic accuracy in predicting respiratory failure and re-intubation.