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The Use of Transesophageal Echocardiography in Cardiac Arrest: Is It the Future?

Adam Broughton, Adam Broughton, MSc, PA-C has a master’s degree in physician assistant studies from the Northeastern University Physician Assistant Program where he is currently working as an assistant professor while continuing to work clinically as an emergency medicine physician assistant.

The integration of echocardiography in to guide decision making has shown promising results since the early 2000’s, but concerns over prolonged delays in chest compressions during cardiopulmonary resuscitation (CPR) may give clinicians and investigators pause when considering wide-spread use and integration into widely used protocols like Advanced Cardiac Life Support (ACLS) with evidence showing adverse effects of prolonged delays in chest compression during CPR. Delays longer than the recommended 30 second pulse checks within ACLS algorithms occurs when performing transthoracic echocardiogram with an ultrasound probe placed on the chest or abdomen possibly obstructing hand placement for chest compressions. By switching to transesophageal echocardiogram (TEE) there is no ultrasound probe on the chest potentially delaying chest compressions during pulse checks which could lead to better adherence to ACLS guidelines in carefully selected patients. Early investigations show promise in both feasibility and early identification of reversible causes of cardiac arrest. This opinion piece calls for more prehospital and hospital-based studies including prospective randomized controlled studies.

Introduction

Point of care ultrasound (POCUS) had become increasingly popular in emergency medicine (EM) in both the bedside diagnosis of disease states as well as rapidly becoming the standard of care in visual guidance during procedures. With smaller, portable, and more affordable ultrasound machines available, the number of providers utilizing POCUS as well as its potential clinical applications is growing every year. One area of particular interest to EM clinicians is the use of ultrasound to identify conditions that need immediate attention in a patient in cardiac arrest, also called “reversible causes” of cardiac arrest within the widely used Advanced Cardiac Life Support (ACLS) protocol. These conditions require rapid reversal to restore circulation, and if missed or not identified early in resuscitation, outcomes are much poorer.

POCUS offers a literal window into the patient’s chest by placing an ultrasound probe directly on the chest wall, which is known as transthoracic echocardiography (TTE) or transthoracic ultrasound. With this, providers can potentially see problems that might lead to cardiac arrest such as compression of the heart from a collapsed lung, known as a tension pneumothorax, or from fluid or blood around the heart preventing it from filling and pumping properly called cardiac tamponade. Both of these conditions need rapid decompression of the air or fluid compressing the heart and neither are easily identifiable by physical examination only, but can very easily be seen by placing an ultrasound probe on the chest and evaluating the heart and lungs. More reliable, early identification of these conditions is very likely to improve outcomes and survival.

Reversible Causes: H’s & T’sIdentifiable with POCUS

Hypovolemia

Cardiac tamponade

Tension pneumothorax

Thrombosis (large PE*)
Yes

Hypo/hyperkalemia

Hypo/hyperthermia

Toxins
No

Table 1: Adapted from the Advanced Cardiac Life Support Guidelines.*PE = Pulmonary Embolism

Early studies in the integration of POCUS in the pre-hospital setting have also shown that it is feasible to perform transthoracic ultrasonography while following established resuscitation protocols and can provide information that can potentially change the treatment plan in critically ill patients particularly in identifying causes of arrest that need immediate intervention. Thus, several authors have proposed standardized techniques and guidelines integrating transthoracic sonography into resuscitation of cardiac arrest.

The only major drawback to transthoracic ultrasonography to evaluate the lungs and heart is that the placement of the probe on the chest is not accessible during high-quality chest compressions. Therefore, most protocols call for evaluation of the heart with ultrasound or TTE during the brief 30 second pulse checks within standard ACLS guided resuscitation of the pulseless patient. Unfortunately, placement of the probe in this position has been shown to lead to prolonged delays during these brief breaks which is detrimental to patient outcomes.3

Thankfully, there is a way to evaluate the heart by ultrasound (echocardiogram) through a probe placed in a patient’s mouth and down into the esophagus known as a Transesophageal Echocardiogram (TEE). This is routinely performed by cardiologists and cardiothoracic surgeons under anesthesia to evaluate heart function in patients with certain cardiac conditions that might need surgery or transplantation. Just as the routine use of TTE by EM providers has increased over the last decade, so too could TEE in the emergency evaluation of cardiac function.

It has already been demonstrated that EM residents can safely and accurately perform TEE in simulated cardiac arrest situations and it has been shown to be feasible and impactful in a prospective study of out-of-hospital cardiac arrest patients undergoing TEE in the emergency department. A recent systematic review of the data of studies on the use of TEE in resuscitation was inconclusive due to small sample sizes, potential bias, and heterogeneity of studies, however a large prospective randomized controlled trial with patients in cardiac arrest would be technically challenging and potentially introducing harm to patients by withholding a modality that could offer a benefit or delaying care if poorly implemented.

Discussion

Education of medical providers often does not reflect the real-world adaptation and use of technological advances. Many EM providers hone and learn new skills throughout their career after training or residency is over. The fact that POCUS is not routinely integrated into the evaluation of patients in cardiac arrest may be due to clinicians either not knowing how to utilize POCUS, or more likely, because it is not part of standard practice and widespread algorithms like ACLS. Why the American Heart Association (AHA) has not adopted or promoted the use of POCUS is not clear while the Advanced Trauma Life Support (ATLS) sponsored by the American College of Surgeons Trauma Committee has long ago adopted the use of ultrasound to help identify intra-abdominal bleeding that could require surgical intervention usually by rapid transfer to the operating room.

It can be argued that POCUS during cardiac arrest may be even more important and time sensitive as the procedures or medications to remedy the reversible causes of arrest are most often done in the emergency department immediately upon finding such a cause, if not already done in the pre-hospital setting by emergency medical personnel. With a rapid, reliable, feasible tool to augment care by accurately identifying immediate life threats, more EM providers should be integrating POCUS into their practice even without direct support from the AHA.

Removing the single downside of TTE in cardiac arrest by performing a TEE should then be the logical next step. With most EM clinicians comfortable with the techniques needed to place airway devices through the mouth into the trachea, it is expected that the same clinicians could also subsequently place an ultrasound probe in the esophagus to evaluate the heart. This would be a logical progression in cardiac arrest where most patients are also in pulmonary arrest or unconscious and need an artificial airway tube and breathing support. The next phase of EM utilization of POCUS is very likely going to be the introduction of a new probe for TEE on the portable ultrasound machines already being used by providers.  

Conclusion    
There is sufficient evidence to support the use of TTE in cardiac arrest with a potential pitfall in delaying chest compressions if not utilized properly. This pitfall is completely avoided by switching to esophageal imaging through TEE. It is unlikely that a large clinical trial would be able to offer randomized, prospective, double-blinded data on the use of TEE in cardiac arrest. Therefore, it is incumbent on EM providers to continue to pursue the highest level of care for their patients and advocate for the use of TEE in the ED more routinely. Industry could potentially influence this by providing esophageal probes and potentially training to go along with the hundreds to thousands of sales of ultrasound units to hospitals yearly.

References:

1. Levitt MA, Jan BA. The effect of real time 2-D-echocardiography on medical decision-making in the emergency department. J Emerg Med. 2002;22(3):229-233. Accessed Apr 1, 2023. doi: 10.1016/s0736-4679(01)00479-6.
2. Huis In 't Veld, Maite A., Allison MG, Bostick DS, et al. Ultrasound use during cardiopulmonary resuscitation is associated with delays in chest compressions. Resuscitation. 2017;119:95-98. https://www.sciencedirect.com/science/article/pii/S0300957217303027. Accessed Apr 1, 2023. doi: 10.1016/j.resuscitation.2017.07.021.
3. Berg RA, Sanders AB, Kern KB, et al. Adverse hemodynamic effects of interrupting chest compressions for rescue breathing during cardiopulmonary resuscitation for ventricular fibrillation cardiac arrest. Circulation. 2001;104(20):2465-2470. Accessed Apr 1, 2023. doi: 10.1161/hc4501.098926.
4. Hussein L, Rehman MA, Jelic T, et al. Transoesophageal echocardiography in cardiac arrest: A systematic review. Resuscitation. 2021;168:167-175. https://pubmed.ncbi.nlm.nih.gov/34390824/. Accessed Apr 1, 2023. doi: 10.1016/j.resuscitation.2021.08.001.
5. Bernstein E, Wang TY. Point-of-care ultrasonography: Visually satisfying medicine or evidence-based medicine? JAMA Internal Medicine. 2021;181(12):1558-1559. https://doi.org/10.1001/jamainternmed.2021.5831. Accessed May 12, 2022. doi: 10.1001/jamainternmed.2021.5831.
6. Panchal AR, Bartos JA, Cabañas JG, et al. Part 3: Adult basic and advanced life support: 2020 american heart association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2020;142(16_suppl_2):S366-S468. Accessed Mar 14, 2023. doi: 10.1161/CIR.0000000000000916.
7. Dewolf P, Wauters L, Clarebout G, Elen J. Timing and identification of the cause and treatment of a cardiac arrest: A potential survival benefit. Medical Principles and Practice. 2022;31(4):384-391. https://www.karger.com/Article/FullText/525553. doi: 10.1159/000525553.
8. Emergency ultrasound - GE healthcare. Vscan™ Family Web site. https://handheldultrasound.gehealthcare.com/emergency-ultrasound/. Accessed Apr 6, 2023.
9. Zengin S, Yavuz E, Al B, et al. Benefits of cardiac sonography performed by a non-expert sonographer in patients with non-traumatic cardiopulmonary arrest. Resuscitation. 2016;102:105-109. https://www.clinicalkey.es/playcontent/1-s2.0-S0300957216001088. doi: 10.1016/j.resuscitation.2016.02.025.
10. Breitkreutz R, Walcher F, Seeger FH. Focused echocardiographic evaluation in resuscitation management: Concept of an advanced life support-conformed algorithm. Crit Care Med. 2007;35(5 Suppl):150. Accessed Apr 1, 2023. doi: 10.1097/01.CCM.0000260626.23848.FC.
11. Chua MT, Chan GW, Kuan WS. Reversible causes in cardiovascular collapse at the emergency department using ultrasonography (REVIVE-US). Ann Acad Med Singap. 2017;46(8):310-316. Accessed Apr 6, 2023.
12. Gardner KF, Clattenburg EJ, Wroe P, Singh A, Mantuani D, Nagdev A. The cardiac arrest sonographic assessment (CASA) exam – A standardized approach to the use of ultrasound in PEA. The American Journal of Emergency Medicine. 2018;36(4):729-731. https://www.sciencedirect.com/science/article/pii/S0735675717307015. Accessed Feb 22, 2022. doi: 10.1016/j.ajem.2017.08.052.
13. Hernandez C, Shuler K, Hannan H, Sonyika C, Likourezos A, Marshall J. C.A.U.S.E.: Cardiac arrest ultra-sound exam—A better approach to managing patients in primary non-arrhythmogenic cardiac arrest. Resuscitation. 2008;76(2):198-206. https://www.sciencedirect.com/science/article/pii/S0300957207004200. Accessed Apr 3, 2022. doi: 10.1016/j.resuscitation.2007.06.033.
14. Lien W, Hsu S, Chong K, et al. US-CAB protocol for ultrasonographic evaluation during cardiopulmonary resuscitation: Validation and potential impact. Resuscitation. 2018;127:125-131. https://www.sciencedirect.com/science/article/pii/S0300957218300613. Accessed Apr 2, 2022. doi: 10.1016/j.resuscitation.2018.01.051.
15. Clattenburg EJ, Wroe P, Brown S, et al. Point-of-care ultrasound use in patients with cardiac arrest is associated prolonged cardiopulmonary resuscitation pauses: A prospective cohort study. Resuscitation. 2018;122:65-68. https://www.sciencedirect.com/science/article/pii/S0300957217307475. Accessed Apr 1, 2023. doi: 10.1016/j.resuscitation.2017.11.056.
16. Chou EH, Wang C, Monfort R, et al. Association of ultrasound-related interruption during cardiopulmonary resuscitation with adult cardiac arrest outcomes: A video-reviewed retrospective study. Resuscitation. 2020;149:74-80. https://www.sciencedirect.com/science/article/pii/S0300957220300666. Accessed Feb 22, 2022. doi: 10.1016/j.resuscitation.2020.02.004.
17. Byars DV, Tozer J, Joyce JM, et al. Emergency physician-performed transesophageal echocardiography in simulated cardiac arrest. West J Emerg Med. 2017;18(5):830-834. https://pubmed.ncbi.nlm.nih.gov/28874934/. Accessed Apr 1, 2023. doi: 10.5811/westjem.2017.5.33543.
18. Teran F, Dean AJ, Centeno C, et al. Evaluation of out-of-hospital cardiac arrest using transesophageal echocardiography in the emergency department. Resuscitation. 2019;137:140-147. https://doi.org/10.1016/j.resuscitation.2019.02.013. Accessed Apr 1, 2023. doi: 10.1016/j.resuscitation.2019.02.013.
19. Bell RM, Krantz BE, Weigelt JA. ATLS: A foundation for trauma training. Annals of Emergency Medicine. 1999;34(2):233-237. https://www.sciencedirect.com/science/article/pii/S0196064499702386. Accessed Apr 14, 2022. doi: 10.1016/S0196-0644(99)70238-6.
20. Wongwaisayawan S, Suwannanon R, Prachanukool T, Sricharoen P, Saksobhavivat N, Kaewlai R. Trauma ultrasound. Ultrasound in medicine & biology. 2015;41(10):2543-2561. https://www.clinicalkey.es/playcontent/1-s2.0-S0301562915003580. doi: 10.1016/j.ultrasmedbio.2015.05.009.
21. O'Neil M, Nagdev A, Teran F. How to perform resuscitative transesophageal echocardiography in the emergency department. www.acepnow.com Web site. https://www.acepnow.com/article/how-to-perform-resuscitative-transesophageal-echocardiography-in-the-emergency-department/. Updated 2020. Accessed April 6, 2022.

Adam Broughton

Assistant Clinical Professor, Department of Medical Sciences, Physician Assistant Program, Northeastern University

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