Feasibility of transesophageal echocardiography in patients with cardiac arrest in Dutch emergency departments

Point-of-care ultrasound is a valuable diagnostic tool during cardiopulmonary
resuscitation (CPR) in cardiac arrest and its use is recommended by
international guidelines. Transthoracic echocardiography (TTE) is most commonly
used, but has certain limitations. Image acquisition can be challenging due to
patient specific factors such as body habitus. Also image quality may be
impacted by the limited acquisition time during CPR pulse checks. Furthermore,
observational data suggests that pulse checks are prolonged due to TTE, while
minimizing interruption of chest compressions is emphasized for better CPR
outcomes in the guidelines. Transesophageal ultrasound (TEE) is a possible
alternative for TTE. It has the theoretical advantage of superior image quality
and thereby possible reductions of chest compression delays. Furthermore, TEE
gives the opportunity determine which part of the heart is compressed most
effectively, which is referred to as the area of maximal compression (AMC).
Animal studies showed that an AMC located over the left ventricle positively
influenced hemodynamics and return of spontaneous circulation (ROSC) compared
to an AMC over the aortic root. In human studies, data also suggests that AMC
located on the left ventricle, as measured by TEE, may positively influence
prognosis.
In the Netherlands, TEE is currently not used in emergency departments during
cardiac arrest. The purpose of this study is to investigate if point-of-care
TEE can be used effectively and safely by providers and teams that have not
previously used this modality. Given the paramount importance of quality of
chest compressions, the ability of the providers to assess the location of the
AMC will be the main focus of this feasibility study.

In the Netherlands, TEE is currently not used in emergency departments during
cardiac arrest. The purpose of this study is to investigate if point-of-care
TEE can be used effectively and safely in patients with cardiac arrest.

Prospective observational feasibility study.

Point-of-care transoesophageal echocardiography will be used as diagnostic
modality during cardiac arrest.

TEE will be used during the study period during cardiac arrest. TEE is widely
used in the hospital in multiple departments. In previous studies concerning
the use of TEE during cardiac arrest no complications of TEE have been
reported. While rare, complications of the use of TEE in general have been
reported. The potential risks are described in more detail in section 4 and 6
of the protocol. The possible benefits include superior diagnostic
characteristics, shorter compression pauses, continuous assessment and
enhancement of chest compressions (see section 1 of the protocol).