# Application of a simplified transesophageal echocardiography examination sequence in high-risk cardiac surgery

## TL;DR

This study tests a simplified three-view TEE protocol to improve efficiency in identifying causes of difficult CPB separation during high-risk cardiac surgery.

## Contribution

A novel simplified TEE protocol (PReTEE) is proposed and tested for faster etiology discrimination during critical cardiac surgery.

## Key findings

- The PReTEE protocol aims to improve efficiency in identifying causes of difficult CPB separation.
- A randomized controlled trial is being conducted to compare PReTEE with conventional TEE in a high-risk cardiac surgery setting.

## Abstract

In cardiac surgical procedures, patients carrying high-risk profiles are prone to encompass complicated cardiopulmonary bypass (CPB) separation. Intraoperative transesophageal echocardiography (TEE), a readily available tool, is utilized to detect cardiac structural and functional pathologies as well as to facilitate clinical management of CPB separation, especially in the episodes of hemodynamic compromise. However, the conventional TEE examination, always performed in a liberal fashion without any restriction of view acquisition, is relatively time-consuming; there appear its flaws in the context of critically severe status. We therefore developed the perioperative rescue transesophageal echocardiography (PReTEE), a simplified three-view TEE protocol consisting of midesophageal four chamber, midesophageal left ventricular long axis, and transgastric short axis.

This is a single-center and randomized controlled trial which will be implemented in Peking Union Medical College Hospital, Beijing, China. A total of 46 TEE scans are schemed to be performed by 6 operators participating in and randomly assigned to either the PReTEE or the conventional TEE group. This study is purposed to investigate whether the efficiency of discriminating leading causes of difficult CPB wean-off can be significantly improved via an abbreviated sequence of TEE views. The primary outcome of interest is the difference between the groups of PReTEE and the conventional TEE in the successful discrimination of etiologies in specified 120 s. Cox proportional hazards model will be further employed to calculate the outcome difference.

The estimated results of this trial are oriented at verifying whether a simplified TEE exam sequence can improve the efficiency of etiologies discrimination during CPB separation in cardiac surgery.

ClinicalTrials.gov NCT05960552. Registered on 6 July 2023.

The online version contains supplementary material available at 10.1186/s13063-024-08338-9.