Transesophageal echocardiography in patients with cardiac arrest: from high-quality chest compression to effective resuscitation

Transoesophageal echocardiography in cardiac arrest: From the emergency department to the intensive care unit

Cardiac arrest is a hyper-acute condition with a high mortality that requires rapid diagnostics and treatment. As such, point-of-care ultrasound (POCUS) has become a valuable tool in the assessment of these patients. While transthoracic echocardiography (TTE) is the more conventional modality used to find reversible causes of cardiac arrest, transoesophageal echocardiography (TOE) has been increasingly utilised due to its superior image quality, continuous imaging, and ability to be operated away from the patient's chest. TOE also has a number of applications in the aftermath of cardiac arrest, such as during the initiation of extracorporeal cardiopulmonary resuscitation (ECPR) and the subsequent monitoring of extracorporeal membranous oxygenation (ECMO). As TOE has evolved, multiple variations have been developed with different utilities. In this article, we will review the evidence supporting the use of TOE in cardiac arrest and where the different forms of TOE can be applied to evaluate the cardiac arrest patient in a timely and accurate manner.

Resuscitative transoesophageal echocardiography performed by emergency physicians in the emergency department: insights from a 1-year period

AIMS

Transoesophageal echocardiography (TOE) has increasingly been described as a possible complementary and point-of-care approach for patients with cardiac arrest (CA). It provides information about potentially reversible causes and prognosis and allows monitoring of resuscitation efforts without affecting ongoing chest compressions. The aim of this study was to assess the feasibility of TOE performed by emergency physicians (EPs) during CA in an emergency department (ED).

METHODS AND RESULTS

This prospective study was performed at the Department of Emergency Medicine at the Medical University of Vienna from February 2020 to February 2021. All patients of ≥18 years old presenting with ongoing resuscitation efforts were screened. After exclusion of potential contraindications, a TOE examination was performed and documented by EPs according to a standardized four-view imaging protocol. The primary endpoint represents feasibility defined as successful probe insertion and acquisition of interpretable images. Of 99 patients with ongoing non-traumatic CA treated in the ED, a total of 62 patients were considered to be examined by TOE. The examination was feasible in 57 patients (92%) [females, 14 (25%), mean age 53 ± 13, and witnessed collapse 48 (84%)]. Within these, the examiners observed 51 major findings in 32 different patients (66%). In 21 patients (37%), these findings led to a direct change of therapy. In 18 patients (32%), the examiner found ventricular contractions without detectable pulse. No TOE-related complications were found.

CONCLUSION

Our findings suggest that EPs may be able to acquire and interpret TOE images in the majority of patients during CA using a standardized four-view imaging protocol.

Left ventricle segmentation in transesophageal echocardiography images using a deep neural network

PURPOSE

There has been little progress in research on the best anatomical position for effective chest compressions and cardiac function during cardiopulmonary resuscitation (CPR). This study aimed to divide the left ventricle (LV) into segments to determine the best position for effective chest compressions using the LV systolic function seen during CPR.

METHODS

We used transesophageal echocardiography images acquired during CPR. A deep neural network with an attention mechanism and a residual feature aggregation module were applied to the images to segment the LV. The results were compared between the proposed model and U-Net.

RESULTS

The results of the proposed model showed higher performance in most metrics when compared to U-Net: dice coefficient (0.899±0.017 vs. 0.792±0.027, p<0.05); intersection of union (0.822±0.026 vs. 0.668±0.034, p<0.05); recall (0.904±0.023 vs. 0.757±0.037, p<0.05); precision (0.901±0.021 vs. 0.859±0.034, p>0.05). There was a significant difference between the proposed model and U-Net.

CONCLUSION

Compared to U-Net, the proposed model showed better performance for all metrics. This model would allow us to evaluate the systolic function of the heart during CPR in greater detail by segmenting the LV more accurately.

[Echocardiography as a Diagnostic Tool in Emergencies and Hemodynamic Instability]

Echocardiography is an imaging method in anaesthesia and intensive care medicine which adds a new dimension to hemodynamic monitoring: the direct visualization of the cardiac function and its disruptions. The review article shows the advantages and limitations of recent transthoracic (TTE) and transesophageal (TEE) echocardiography in the diagnostic course of hemodynamic instability. For TTE and TEE focused examination techniques and sequences are illustrated with regards to their fast applicability to hemodynamic monitoring.