Norm of Transesophageal Ultrasonography (Transesophageal Echocardiogram, TEE)
Negative or normal structure or function and absence of a pathologic condition.
Usage of Transesophageal Ultrasonography (Transesophageal Echocardiogram, TEE)
Transesophageal echocardiogram (TEE) is especially indicated for examination of prosthetic heart valves; detection of mitral valve regurgitation, aortic dissection (site and extent), congenital heart disease of the adult, cardiac tumors and masses, embolic or thrombotic disorders (particularly of the left atrium), vegetative endocarditis; and intraoperative guide to left ventricular function. Used for clients with conditions making standard transthoracic echocardiograms unreliable, such as obesity, chest deformities, chronic lung disease, or intubation; provides guidance for pericardiocentesis in cardiac tamponade; helps evaluate for transvenous pacemaker malposition; newer use in ruling out the presence of atrial thrombus before cardioversion as an alternative to anticoagulation.
Description of Transesophageal Ultrasonography (Transesophageal Echocardiogram, TEE)
Ultrasound uses high-frequency sound waves to induce vibrations that echo or reflect from the solid structures within the body. These echoes create images from which chamber and valve size, function, and pericardial effusion can be determined. A specially adapted flexible gastroscope is fitted with a high-frequency transducer to send, receive, and translate the reflected vibrations. This tube, when swallowed or advanced into the esophagus, is positioned behind the heart and related structures. It can be rotated anteriorly, laterally, or posteriorly to allow an unimpeded route for sound-wave reflection off the heart chambers, walls, and valves. Abnormalities that are missed by standard diagnostic techniques can be displayed. Only the upper aortic view is limited by the interference of the left mainstem bronchus. The newest echocardiographic equipment includes three-dimensional capabilities, which can provide many views of the heart structures.
Professional Considerations of Transesophageal Ultrasonography (Transesophageal Echocardiogram, TEE)
Consent form IS required.
Vasovagal bradycardia and drug-induced tachycardia are likely dysrhythmias; esophageal perforation; bleeding; transient hypoxemia; oversedation.
Esophageal obstructions, stenosis, fistula, or dysphagia; history of radiation therapy to the esophagus or surrounding area (mediastinum); acute penetrating chest injuries. Neonates and young children are not candidates because of the unavailability of specially sized TEE scopes. Sedatives are contraindicated in clients with central nervous system depression. Also contraindicated in clients who cannot tolerate lying flat.
- See Client and Family Teaching.
- Obtain a chest radiograph, ECG, and laboratory work, including CBC, electrolytes, PT, and PTT.
- Start an IV infusion at KVO (keep-vein-open) rate for administration of sedation or emergency medications.
- Remove dentures and glasses. Have the client void before the procedure.
- A drying agent is typically given to reduce secretions (that is, glycopyrrolate 0.1–0.2 mg IV). Some clients require a small IV dose of an antianxiety agent (such as midazolam or diazepam). Prophylactic antibiotics are usually given if the client has a prosthetic valve.
- Just before beginning the procedure, take a “time out” to verify the correct client, procedure, and site.
- The client is monitored continuously: heart rate and rhythm by cardiac monitor, blood pressure by noninvasive monitor, and O2 by pulse oximetry.
- Position the client in the left lateral decubitus position.
- Topical anesthesia per physician preference is used to numb the throat and suppress the gag reflex. This may be repeated several times during the procedure.
- The client should be awake enough to follow commands but drowsy. This procedure may also be performed on a fully anesthetized or intubated client.
- The client is asked to open the mouth and flex the neck forward in a chin-to-chest position.
- The lidocaine-lubricated probe is inserted, and the client is asked to swallow.
- Over the next 5–20 minutes the probe is gently withdrawn, and cardiac images are viewed or recorded at different levels.
- The nurse remains with the client to monitor respiratory status, vital signs, and cardiac rhythm and to assess the need for further sedation or suctioning.
- Continue assessment of respiratory status. If deep sedation was used, follow institutional protocol for post sedation monitoring. Typical monitoring includes continuous ECG monitoring and pulse oximetry with continual assessments (every 5–15 minutes) of airway, vital signs, and neurologic status until client reaches level 3, 2, or 1 on the Ramsay Sedation Scale.
- Once the gag reflex has returned, the client can resume fluid intake. Full diet is not recommended until 3 hours after procedure.
Client and Family Teaching
- Fast for 6–8 hours before the test. Medications may be taken with a small amount of water as directed by the physician. You will have to remove your dentures and eyeglasses, but you should keep your hearing aid on so that you can hear the physician's instructions.
- You will be given a sedative for the procedure. You should arrange for someone to drive you home because you may be drowsy after the procedure and will not be permitted to drive.
- Do not eat or drink for 4–6 hours before the procedure. Take any prescription medications with a small sip of water.
- This procedure lets the physician look at your heart and its major blood vessels from the back, without the lungs blocking the view. A flexible tube about the thickness of a pen is inserted into the mouth and moved down into the esophagus. The tip of the tube produces sound waves that bounce off the heart and are changed into pictures on a video screen.
- Breathe through the nose and swallow during introduction of the probe, and breathe through the mouth for the remainder of the procedure, which takes about 30 minutes.
- Your tongue and throat may feel swollen after the topical anesthetic; your mouth and lips will feel sticky and dry if a drying agent is used. Do not eat or drink after the procedure until the numbness is gone.
- The doctor must review the videotape of the procedure before discussing the test results.
- Discharge instructions: Promptly report persistent sore throat, dysphagia, stiff neck, and epigastric, substernal, or abdominal pain that worsens with breathing or movement.
Factors That Affect Results
- See the description of the test.