While transesophageal echocardiography (TEE) dates back to the early 1970s and 1980s,1–4 it was not routinely used by cardiologists until the mid-1990s.5 By the late 1990s and early 2000s, the safety of TEE was well recognized,6 with studies describing the use of resuscitative TEE for cardiopulmonary resuscitation (CPR) mechanics and determining causes of cardiac arrest.7–9
The first report of emergency physicians using TEE for cardiac arrest management was published in 2008.10 More recently, there has been exponential growth in resuscitative TEE by emergency physicians, sparked by pioneering publications and the availability of high-fidelity scan trainers.11–17 In 2018, national guidelines for point-of-care TEE applications were published, delineating training, credentialing, and goal-directed protocols.18 The rapid adoption and excitement over emergency TEE is the result of the breaking down of financial and political barriers, as well as the incredible utility of this state-of-the-art resuscitation tool.
Clinical indications for resuscitative TEE are similar to those for point-of-care transthoracic echocardiography (TTE) (see Chapter 5, “Transthoracic Echocardiography”). However, TEE is specifically indicated when TTE images are inadequate, access to the patient’s chest is limited, excellent image quality with fine detail is required to make or rule out a specific diagnosis, or when clinicians wish to continually monitor cardiac function. Specific clinical indications for resuscitative TEE include the following:
Massive pulmonary embolism
Regional wall motion abnormalities
Pericardial effusion and tamponade
Acute aortic dissection
Cardiac arrest discontinues cerebral blood flow, which produces loss of consciousness within 6 seconds.19 If anoxia lasts longer than 4 minutes, brain cells will permanently be lost,20 highlighting the importance of robust CPR, rapidly determining reversible causes, and achieving return of spontaneous circulation (ROSC).
Resuscitative TEE for cardiac arrest is considered by some to be the most valuable indication for acute care providers. This application requires training (and further research) to achieve maximum benefits in patient care. Most cardiac arrest algorithms neglect the importance of determining presence and degree of cardiac activity. Pulse checks in adult and pediatric populations are time consuming and unreliable.21,22 TEE allows the clinician to immediately establish the presence or absence of cardiac activity with certainty, resulting in shorter compression pauses compared with TTE (Figure 6-1, Video 6-1).14,23 Compared to TTE, continuous high-quality TEE images are generally easier to acquire during CPR.
(A) Midesophageal five-chamber view and corresponding video demonstrating absence of organized cardiac activity with scant valve motion (Video 6-1A). (B) Transgastric short-axis view and corresponding video showing absence of cardiac activity, followed by resumption of chest compressions (Video 6-1B). LA = left atrium, LV = left ventricle, RA = right atrium, RV = right ventricle.