Introduction to Transesophageal Echo – Basic Technique

Thanks to Dr. Jennifer Cloutier, Cardiac Anesthesiologist, for delivering a great session.


This beginner guide is designed for those familiar with transthoracic echo and just starting to use TEE. ED indications and TEE utility in the emergency setting are briefly discussed at the end of this post.


Requirements

  • Sterile transducer – This requires a sterilization facility, protocol and collaboration with other departments
  • Patient preparation – In ED usually intubated, unconscious or sedated.
  • Optional – spray the transducer with topical local anesthetic

Contraindications

  • Suspected esophageal perforation, stricture or trauma
  • Varices

Insertion

  • Hold transducer control module with left hand and support against your abdomen (see pic 1)
  • Extend transducer to full length, holding end with right hand
  • Check the control wheels are functioning correctly before inserting the transducer
  • Ensure transducer head is facing upwards (use anterior length markings to maintain orientation)
  • Insert transducer on left side of tongue
  • Use bite guard – e.g cut corrugated airway tubing
  • Advance to mid esophagus
  • Look for left atrium – this is the first window

 

Orientation

The transducer can be manipulated into several orientations:

  • Rotate control module clockwise to orientate to patient right
  • Rotate control module anticlockwise to orientate to patient left
  • Rotate “Big Wheel” clockwise to antiflex and orientate anteriorly
  • Rotate “Big Wheel” anticlockwise to retroflex and orientate posteriorly
  • Rotate “Small Wheel” clockwise to flex right
  • Rotate “Small Wheel” anticlockwise to flex left
  • Advance transducer deeper into esophagus
  • Withdraw transducer less deeply in esophagus

(a) Advance, withdraw: Pushing or pulling the tip of the TEE probe; (b) turn to right, turn to left (also referred as clockwise and anticlockwise): rotating the anterior aspect of the TEE probe to the right or left of the patient; (c) anteflex, retroflex: anteflex is flexing the tip of the TEE probe anteriorly by turning the large control wheel clockwise. Retroflex is flexing the tip of the TEE probe posteriorly by turning the large wheel anticlockwise; (d) Flex to right, Flex to left: flexing the tip of the TEE probe with the small control wheel to the patient’s right or left. The probe flexion to the right and left may not be necessary and should be avoided to minimize trauma to the esophagus 

 

 

Multiplane Imaging Angle

With all modern TEE transducers the transducer beam can be rotated within the probe to generate different beam angles. This is achieved using 2 buttons on the control module, one button rotates from 0 to 180 degrees, the other button rotates it back from 180 to 0 degrees. Using the buttons in combination any desired angle between 0 and 180 degrees can be achieved.

At 0 degrees the transducer beam is transverse (orientated Left screen – Right patient)

At 90 degrees the transducer beam is longitudinal

At 180 degrees the transducer beam is transverse (orientated Left screen – Left patient)

 

Multiplane Imaging angle is depicted on the monitor using a pictogram dial.

In this example the TEE probe is located in the Mid Esophageal location. View A – the multiplane imaging angle is 10 degrees and a 4 chamber view is generated. View B – the multiplane imaging angle is 90 degrees and a 2 chamber view is generated.

 

 


 

Useful video tutorial explaining orientation

 

 


 

Core Views

For the beginner, standard views can be achieved by using a guide that shows the location of the transducer (e.g Mid Esophageal, Trans-Gastric along with the optimal multiplane angle (see below).

Clearly every patient will have slightly different anatomy and cardiac axis, so these guides are just a starting point. Fine tuning of all the above will be required.

The Consensus Statement of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists provides an excellent outline of the basic perioperative TEE examination. Although this examination is likely to be much more comprehensive than what is needed in the Emergency Department (e.g during a code or peri arrest), it provides a useful guide to practicing all the important views that may be required in most situations.

 


 

This short video tutorial provides a useful outline of core views

 


ME 4 Chamber View


 

Indications

  • Cardiac Arrest – continuous echo evaluation of cardiac contractility, without impacting chest compression
  • Peri Arrest – assists with diagnosis and fluid resuscitation,
  • Undifferentiated Hypotension – assists with diagnosis and fluid resuscitation

US Probe: Transesophageal Echocardiography in Cardiac Arrest

The post above and the article below provide a more detailed discussion on the use of TEE in cardiac arrest.

New Concepts of Ultrasound in the Emergency Department: Focused Cardiac Ultrasound in Cardiac Arrest

 

 


References

Reeves ST, Finley AC, Skubas NJ, et al. Basic perioperative transesophageal echocardiography examination: a consensus statement of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. J Am Soc Echocardiogr. 2013;26(5):443–456. doi:10.1016/j.echo.2013.02.015

Arntfield, Robert et al. Focused Transesophageal Echocardiography by Emergency Physicians is Feasible and Clinically Influential: Observational Results from a Novel Ultrasound Program. Journal of Emergency Medicine, Volume 50, Issue 2, 286 – 294

 


Further Reading and Viewing

 

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