eMedicine Specialties > Gastroenterology > Systemic Disease

Esophagogastroduodenoscopy

Author: Tony E Yusuf, MD, Assistant Professor, Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, The University of Texas - Houston Medical School
Coauthor(s): Scott A Wofford, MD, Fellow, Department of Gastroenterology, Hepatology and Nutrition, University of Florida; Manoop S Bhutani, MD, FACG, FACP, Professor, Department of Medicine, Division of Gastroenterology, Director, Center for Endoscopic Ultrasound, Co-Director, Center for Endoscopic Research, Training and Innovation, University of Texas Medical Branch at Galveston
Contributor Information and Disclosures

Updated: Aug 2, 2007

Introduction

Esophagogastroduodenoscopy (EGD) is a procedure during which a small flexible endoscope is introduced through the mouth (or with smaller caliber endoscopes, through the nose) and advanced through the pharynx, esophagus, stomach, and duodenum. An enteroscope, a longer endoscope, can be introduced beyond the ligament of Treitz into the jejunum. EGD is used for both diagnostic procedures and therapeutic procedures. Most modern endoscopes now use a video chip (charged coupled device) for better imaging, as opposed to the older endoscopes, in which fiber optics are used for image transmission.

In the United States, the procedure is usually performed while the patient is under conscious or moderate sedation, although it can be performed with only topical anesthesia (common practice in Europe and Asia). General anesthesia is often used in a selected group of patients who are difficult to sedate due to chronic narcotics intake. The procedure is usually performed in a dedicated endoscopy unit in the hospital or outpatient office setting but can also be done in the emergency department, intensive care unit, or operating room using portable endoscopy carts. Using various types of equipment and endoscopes, endoscopic ultrasound (EUS), endoscopic retrograde cholangiopancreatography (ERCP), and small bowel enteroscopy can also be performed.

Preparation

General

Ideally, the patient should have nothing by mouth (ie, NPO) for at least 6 hours prior to the procedure to allow for adequate gastric emptying. If conscious sedation is used, intravenous access and standard monitoring are also needed. Informed consent should be obtained from the patient (or their legal representative if the patient is unable to give informed consent) prior to the procedure. A patient history should be obtained, and a physical examination should be performed to determine if performing the procedure is appropriate.

Patient assessment

A complete history should be obtained, and a physical examination should be performed. Findings should be documented in the patient's medical record. Special attention is directed to certain illnesses that might bear a direct effect on endoscopy, such as cardiovascular and pulmonary diseases. History of drug allergies and previous abdominal surgeries should also be obtained.

Preprocedure testing in selected cases might include, but is not limited to, a complete blood cell count, blood crossmatching, coagulation studies, a chemistry panel, urinalysis, pregnancy testing, electrocardiogram, and chest radiographs. No data support routine laboratory testing prior to elective outpatient endoscopy. Preprocedure tests should be individualized and based on information obtained from the patient's history and physical examination and the indication for the procedure.

Informed consent

Obtaining informed consent prior to each endoscopic procedure is extremely important and is the responsibility of the endoscopist. The indications, nature, and relevant details of the procedure should be explained to the patient. Risks, benefits, alternatives, and complications should also be presented to the patient. The consent form should be signed and dated by the patient and endoscopist and must be witnessed by other personnel and placed in the patient record.

Antibiotic prophylaxis

Transient bacteremia may occur during most endoscopic procedures, but the risk of infectious complications (including endocarditis) is low. Antibiotic prophylaxis is clearly recommended when patients with an underlying high-risk condition for infectious complications (eg, prosthetic heart valve, history of endocarditis) undergo a high-risk endoscopic procedure, such as stricture dilation, sclerotherapy of varices, and ERCP, in the presence of an obstructed biliary tree. All patients undergoing percutaneous endoscopic gastrostomy placement should receive antibiotic prophylaxis against soft tissue infections; the regimen usually includes cefazolin (1 g IV).

The patient's condition and the nature of the procedure should be reviewed carefully, and the decision to administer antibiotic prophylaxis is individualized. An acceptable prophylaxis regimen is parenteral ampicillin at 2 g and gentamicin at 1.5 mg/kg (up to 80 mg) 30 minutes prior to the procedure. Vancomycin (1 g IV) is substituted for penicillin in patients who are allergic to penicillin.

Specific recommendations for antibiotic prophylaxis based on the type of the endoscopic procedure that is being contemplated and the underlying patient condition are available from the American Society for Gastrointestinal Endoscopy (ASGE).

Anticoagulants and esophagogastroduodenoscopy

Diagnostic EGD is considered a low-risk procedure for bleeding in patients on anticoagulants and, therefore, can be performed without adjustment of anticoagulants prior to the procedure. However, if polypectomy is contemplated or conceivable, then the patient's coagulation profile should be normalized. A risk of retropharyngeal hematoma also may be present in patients with severe coagulation abnormalities. Certain therapeutic procedures (ie, dilations, percutaneous gastrostomy, polypectomy, endoscopic sphincterotomy, EUS-guided fine-needle aspiration, laser ablation, coagulation) are considered high-risk procedures for bleeding, and adjustment of anticoagulation may be necessary.

Indications

• Diagnostic evaluation for signs or symptoms suggestive of upper GI disease (eg, dyspepsia, dysphagia, noncardiac chest pain, recurrent emesis)
• Surveillance for upper GI cancer in high-risk settings (eg, Barrett esophagus, polyposis syndromes)
• Biopsy for known or suggested upper GI disease (eg, malabsorption syndromes, neoplasms, infections)
• Therapeutic intervention (eg, retrieval of foreign bodies, control of hemorrhage, dilatation or stenting of stricture, ablation of neoplasms, gastrostomy placement)

Contraindications and Relative Contraindications

Contraindications include possible perforation, medically unstable patients, or unwilling patients.

Relative contraindications include anticoagulation, pharyngeal diverticulum, or head and neck surgery.

Complications

The major complications of EGD are bleeding, infection, perforation, and cardiopulmonary problems. Approximately 1 complication occurs for every 1000 procedures. The mortality rate is estimated to be 0.5-3 deaths for every 10,000 procedures. Cardiopulmonary events comprise 50% of all major complications, and most of these events result from the medications used for conscious sedation.

Equipment

Endoscopes are available from several different manufacturers (eg, Olympus, Pentax, Fujinon). The conventional endoscope consists of an umbilical cord, control head (wheels for up/down and left/right, air/water button, and suction button), insertion tube of 100 cm length and 8-11 mm external diameter, and bending section at the tip (which allows up to 180° deflection for retroflexion of the endoscope). The endoscope contains a lumen for insufflation of air and water, a working channel of 2-3 mm diameter (larger channel diameter for therapeutic endoscopes) used for suctioning and passage of instruments, control wires for moving the tip of the endoscope, and the imaging system that is either fiberoptic (rare) or video (widely available). The endoscope, light source, and image source (either video monitor or direct-view through the eyepiece) are essential equipment. Images and video can be recorded and printed depending on the equipment used.

Flexible ultrathin fiberoptic and video endoscopes that can be used without sedation are also available for EGD. These endoscopes are inserted transnasally or perorally and have a working length of 925-1050 mm, an external diameter of 5.3-6 mm, and a working channel diameter of 2 mm.

Multiple instruments can be introduced through the working channel of the endoscope. These instruments include biopsy forceps, snares, sclerotherapy needles, heater probes, electrocautery probes, balloon-dilation devices, nets, and baskets. Guidewires can be placed, and, when the endoscope is withdrawn, wire-guided bougie dilators can be passed. Devices can also be placed onto the end of the endoscope for banding of esophageal varices and endoscopic mucosal resection.

Some of the newer endoscopes provide high resolution and magnifying endoscopy and are used for the evaluation of certain upper gastrointestinal diseases. The upper endoscope is also used to guide endoscopic treatment of gastroesophageal reflux disease (GERD), such as with the Bard EndoCinch endoscopic suturing device and the NDO full-thickness plicator.

One of the recent advances in video endoscopy is narrow band imaging (NBI). NBI uses optical filters and high relative intensity of blue light for imaging and characterization of mucosal morphology, such as mucosal and superficial vascular patterns. NBI has been studied in patients with Barrett esophagus, early gastric tumors, and colorectal lesions and has had promising results.

The Procedure

The patient is usually placed in the left lateral position. Topical and/or intravenous sedation is administered to minimize gagging and to facilitate the procedure. A bite block is placed to prevent damage to the endoscope and to ease its passage through the mouth. The endoscope is then passed under direct vision through the pharynx, esophagus, and stomach and into the duodenum, with careful inspection upon both insertion and slow withdrawal. Air is insufflated to distend the lumen to aid in viewing. Liquid and particulate matter can be aspirated through the suction channel.

The procedure and findings can be documented with pictures or a video system. Biopsy specimens can be obtained by passing forceps and taking small mucosal samples for histology studies. A number of therapeutic procedures can be performed during the endoscopy. The procedure may last from 5-30 minutes or longer, depending on which diagnostic or therapeutic maneuvers are used. After completion of a procedure performed under conscious sedation, the patient is transferred to a recovery room for further monitoring by an endoscopy nurse. Once alert and mobile (after approximately 1 h), the patient is allowed to leave the recovery room with an escort and is given postprocedure instructions (eg, diet, activity) and advised to observe for signs and symptoms of GI bleeding, fever, and abdominal pain. A follow-up appointment with the primary care physician and/or the endoscopist is usually arranged prior to patient's discharge from the endoscopy unit.

Sedation and Miscellaneous Protocols

Sedation

In the United States, conscious sedation and topical anesthesia are commonly used for EGD. The use of monitored anesthesia care and propofol (Diprivan) is gaining wide acceptance because of the short recovery time. However, in many other countries, EGD is performed with topical anesthesia only. Topical anesthesia (eg, Cetacaine, lidocaine) has the advantages of requiring less time for the overall procedure, eliminating the risk of sedation, and decreasing the cost of the procedure by reducing or eliminating recovery time and nursing staff. The disadvantages are patient discomfort and problems in performing the procedure on a patient who may not be still. With the cost-saving trends in medicine, EGD without sedation will likely become more commonplace in the United States. With the introduction of smaller caliber endoscopes that can be passed through the nose, EGD without sedation may be more acceptable to patients.

When conscious sedation is being administered, the patient must be monitored throughout the procedure. Pulse oximetry, heart rate, and blood pressure are commonly monitored. Electrocardiographic monitoring is recommended in patients with cardiopulmonary disease, in elderly patients, and during a prolonged procedure.

Pharmacology of commonly used sedatives, analgesics, and reversal agents

• Benzodiazepines
  • Midazolam (Versed) is a sedative/hypnotic commonly used for sedation in endoscopic procedures. The peak effect of midazolam is 3-5 minutes, with a duration of action of 1-3 hours. Some of the major adverse effects include respiratory depression, hypotension, and paradoxical agitation. The typical starting dose is 0.5-2 mg IV, which can be titrated to achieve a desirable level of sedation (usually in 1-mg increments). Lower doses of midazolam should be administered to elderly patients with cardiopulmonary problems to avoid serious complications.
  • Diazepam (Valium) may be used instead of midazolam for sedation during endoscopic procedures, but many centers prefer midazolam (over diazepam) because of its amnestic effect and reduced tendency to cause phlebitis.
• Opioids
  • Meperidine (Demerol) is a narcotic analgesic that has mild sedative properties, slow onset of action, long duration, and long recovery time. When coadministered with benzodiazepines, potential complications include respiratory depression and sedation. The peak effect of meperidine is approximately 10 minutes, with a duration of action of 2-3 hours. Adverse effects include respiratory depression, hypotension, nausea, and vomiting. The typical starting dose is 15-50 mg IV, with subsequent doses not to exceed 25 mg/dose.
  • Fentanyl (Sublimaze) is a mildly sedative narcotic analgesic that has a rapid onset of action and short recovery time. In many endoscopy centers, fentanyl is the preferred agent for outpatient endoscopic procedures. The peak effect is 5-8 minutes, and the duration of action is 1-3 hours. One of the major adverse effects is respiratory depression. The typical starting dose is 0.03-0.1 mg IV, with subsequent doses of 0.02-0.05 mg/dose.
• Reversal agents
  • Flumazenil (Romazicon) is typically used for reversal of benzodiazepine-induced sedation and respiratory depression. Flumazenil has a peak effect of 3-5 minutes and a duration of action of 1-2 hours. Potential adverse effects include resedation and seizures. The typical dose is 0.2-0.5 mg IV for reversal of sedation (up to 1 mg total) and 1-3 mg IV for benzodiazepine overdose.
  • Naloxone (Narcan) reverses opioid-induced analgesia, CNS effects, and respiratory depression. Naloxone has a peak effect of 1-2 minutes and a duration of action of 1-3 hours. Adverse effects include pain, agitation, nausea, vomiting, arrhythmias, sudden death, pulmonary edema, and withdrawal syndrome in patients with opioid abuse. The typical dose is 0.04 mg IV for reversal of analgesia/sedation and 0.4 mg for narcotic overdose and respiratory arrest.

Infection control during gastrointestinal endoscopy

Despite the large number of endoscopic procedures performed each day, the incidence of infection transmission via endoscopes remains very rare.

Methods of reprocessing endoscopes include mechanical cleaning, high-level disinfection, rinsing, and drying. Proper and diligent care during reprocessing of endoscopes, with attention to quality control, cannot be overstated for minimizing the risk of spreading infection via endoscopic procedures.

Establishment of gastrointestinal endoscopy areas

Endoscopy units are specific areas in a hospital (or physician's office) in which all endoscopic procedures are performed. For this unit to be functional and effective, the ASGE recommends that certain conditions must be met. These conditions include a properly trained endoscopist and nursing staff, functioning and adequately maintained equipment, an endoscope cleaning area, personnel trained to perform cardiopulmonary resuscitation, and a quality improvement program.

Open access endoscopy

Open access endoscopy is a system designed to offset the cost of endoscopy in stable patients without significant comorbidities who have clear indications for upper endoscopy. The responsibilities of the referring physician are complete understanding of the patient's condition and the accepted indications for endoscopy. If the patient is on anticoagulation or if antibiotic prophylaxis is required, these issues must be addressed via proper communication between the referring physician and the endoscopist.

Training and certification requirements for endoscopists

The ASGE recommends that training in upper endoscopy include an understanding of indications, limitations, contraindications, alternatives, principles of conscious sedation, and correct interpretation of endoscopic findings. A minimum of 100 upper endoscopic procedures is recommended for trainees to become competent in diagnostic upper endoscopy. Therapeutic upper endoscopy requires further training and experience to gain competency. The recommendations of the ASGE for the number of procedures required to gain competency in various therapeutic upper endoscopic procedures are available through the society Web site (see American Society for Gastrointestinal Endoscopy).

Multimedia

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Media file 1: Esophagogastroduodenoscopy (EGD). Normal vocal cords as seen prior to entering the esophagus during video EGD.

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Media file 2: Esophagogastroduodenoscopy (EGD). Normal lower esophageal sphincter seen during EGD.

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Media file 3: Esophagogastroduodenoscopy (EGD). Normal pylorus seen during EGD.

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Media file 4: Esophagogastroduodenoscopy (EGD). Normal duodenum in the area of the ampulla, as seen during EGD.

Keywords

EGD, gastroscopy, upper gastrointestinal endoscopy, GI endoscopy, upper GI endoscopy, endoscope

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