Endoscopic Ultrasonography (EUS)

Norm of Endoscopic Ultrasonography (EUS)

Requires interpretation. Lipomas image as bright and echogenic. Tumors are usually dark and hypoepogenic, often with irregular borders.

 

Usage of Endoscopic Ultrasonography (EUS)

Gastrointestinal (GI) cancer staging; imaging of lymph node metastasis from the GI tract to help determine TNM staging; screening for cancer in clients with Barrett's esophagus; screening for recurrence of GI cancer of all types. Provides guidance for fine-needle aspiration biopsies of the abdominal organs and lymph nodes. EUS-guided FNA may help diagnose lung masses adjacent to the esophagus. More sensitive than upper GI endoscopy for diagnosing varices. Evaluation for the presence of stones in the common bile duct. More accurate than any other tests for detection of pancreatic cancer. Simple tool to assess and diagnose aberrant right subclavian artery (ARSA). Some therapeutic uses are also being investigated.

 

Description of Endoscopic Ultrasonography (EUS)

One of the newest uses for ultrasonography involves taking ultrasound images from within the GI tract. EUS improves diagnostic accuracy by reducing artifacts that occur from anatomic structures and gas when imaging from the exterior of the body. Because the ultrasound probe is much closer to the area being examined, higher frequency ultrasound can be used, which normally is not an option when imaging from greater distances. Higher frequencies can provide clearer images of smaller areas and better detail of the layers of the GI tract, which are often the site where cancer begins.

 

Professional Considerations of Endoscopic Ultrasonography (EUS)

Consent form IS required.

Risks Vasovagal bradycardia and drug-induced tachycardia are likely dysrhythmias; esophageal perforation; bleeding; transient hypoxemia; oversedation. Contraindications 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 scopes. Sedatives are contraindicated in clients with central nervous system depression and in clients who cannot tolerate lying flat.

 

Preparation

1. See Client and Family Teaching.
2. Document clinical indications on the test requisition. This helps guide the interpreter to provide the most relevant test interpretation.
3. Start an IV infusion at KVO (keep vein open) rate for administration of sedation or emergency medications.
4. Remove dentures and eyeglasses. Have the client void before the procedure.
5. Obtain local anesthetic spray.
6. 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.
7. Just before beginning the procedure, take a “time out” to verify the correct client, procedure, and site.

 

Procedure

1. The client is monitored continuously: heart rate and rhythm by cardiac monitor, blood pressure by noninvasive monitor, and O2 by pulse oximetry.
2. Position the client in the left lateral decubitus position.
3. 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.
4. The client should be awake enough to follow commands, but drowsy. This procedure may also be performed on a fully anesthetized or intubated client.
5. The client is asked to open the mouth and flex the neck forward in a chin-to-chest position.
6. The lidocaine-lubricated probe is inserted, and the client is asked to swallow.
7. A small flexible tube equipped with an ultrasonic probe and camera at the tip is inserted through the mouth or rectum and advanced into the GI tract. Ultrasonic images are taken at points appropriate to the clinical indications for the procedure.
8. 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.

 

Postprocedure Care

1. 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.
2. Once the gag reflex has returned, the client can resume fluids. Full diet is not recommended until 3 hours after procedure.

 

Client and Family Teaching

1. This procedure involves having a narrow, flexible tube inserted through your mouth and esophagus into your stomach and small intestine and having an ultrasound picture taken from inside the body.
2. 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.
3. 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.
4. Do not eat or drink for 4–6 hours before the procedure. Take any prescription medications with a small sip of water.
5. Bowel preps may be ordered for lower EUS.
6. The test takes about 45 minutes.
7. The tongue and throat may feel swollen after the topical anesthetic; the 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.
8. Home 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

1. None found.

 

Other Data

1. None found.