INTRODUCTION — Upper gastrointestinal (GI) endoscopy (esophagogastroduodenoscopy [EGD]) includes visualization of the oropharynx, esophagus, stomach, and proximal duodenum, with real-time assessment and interpretation of the findings encountered. This topic will review factors associated with performing an upper endoscopy, including indications, patient preparation, technical aspects, tissue sampling, and complications. Detailed discussions of specific diagnostic and therapeutic interventions carried out during an upper endoscopy and special considerations for upper endoscopy in the setting of the COVID-19 pandemic are presented separately. (See "Endoscopic interventions for nonmalignant esophageal strictures in adults" and "Methods to achieve hemostasis in patients with acute variceal hemorrhage" and "Overview of the treatment of bleeding peptic ulcers" and "Barrett's esophagus: Surveillance and management" and "Overview of the treatment of achalasia" and "Overview of endoscopic resection of gastrointestinal tumors" and "COVID-19: Issues related to gastrointestinal disease in adults", section on 'Implications for endoscopy' and "Wireless video capsule endoscopy".)
PATIENT SELECTION
Indications — In general, upper endoscopy is recommended if the results are likely to influence management of the patient, if empiric treatment for a suspected benign disorder has been unsuccessful, if the procedure can be used as an alternative to or to investigate a finding on radiographic evaluation, or if a therapeutic maneuver may be needed. Diagnostic, screening/surveillance, and therapeutic indications for upper endoscopy are outlined in the table (table 1) [1]. In addition, upper endoscopy is indicated if the results would affect the management of other diseases (eg, a patient with a history of upper gastrointestinal (GI) bleeding who requires anticoagulation or treatment with a nonsteroidal anti-inflammatory drug). Upper endoscopy is generally not indicated when the results will not affect management or for periodic surveillance of benign lesions unless surveillance of a premalignant condition is warranted.
Contraindications — Relative contraindications for upper GI endoscopy include:
●Patients who cannot tolerate moderate sedation, monitored anesthesia care (MAC), or general anesthesia in whom unsedated upper endoscopy is not feasible (see "Sedation-free gastrointestinal endoscopy")
●Patients who are hemodynamically unstable
●Patients with GI obstruction
●Patients with abnormal coagulation studies (platelet count <20,000/microL), particularly if biopsies or therapeutic maneuvers are anticipated
In addition, patient selection must take into account not only the indication(s) for the procedure but also patient-related factors, such as comorbid illnesses, that might increase the risk of performing an upper endoscopy or make the examination more difficult. As with any procedure, patients in whom the risks of upper endoscopy are believed to outweigh the benefits should not undergo the procedure. Whether the procedure is urgent or elective, decisions regarding the timing of endoscopy and the management of antiplatelet agents in such patients should involve both the gastroenterologist(s) and prescribing clinician(s) caring for the patient. (See "Management of antiplatelet agents in patients undergoing endoscopic procedures" and "Noncardiac surgery after percutaneous coronary intervention", section on 'Our approach'.)
PREPROCEDURE CONSIDERATIONS — Prior to the procedure, patients should be evaluated for other factors that may affect the ability to safely and successfully perform an upper endoscopy.
Presedation assessment — Patients require a presedation evaluation to identify underlying conditions that may increase risk and to create a plan for procedural sedation that minimizes risk while managing coexisting medical conditions. Presedation assessment should include an evaluation of the following:
●Anatomic considerations such as a small mouth or a limited range of motion in the jaw (factors that may make it difficult to insert the protective mouth piece), a limited range of motion of the neck that may make correct patient positioning difficult, or the presence of a Zenker's diverticulum, which increases the difficulty and risk of esophageal perforation during esophageal intubation.
●Comorbid illnesses that may increase the risks associated with sedation.
●Use of medications such as benzodiazepines, narcotics, or cannabis that may increase a patient's tolerance to the effects of sedation [2-5]. This includes taking a complete history of factors that might make sedation more difficult, such as prior difficulties with sedation, narcotic or benzodiazepine use, diminished mental capacity, and agitation or severe anxiety. It also includes considering whether the patient has any characteristics that pose an increased risk for aspiration (eg, ascites, nonempty stomach, active bleeding), difficult airway management (eg, obesity, nonvisibility of the uvula, prior history of difficult intubation), or increased cardiopulmonary complications of endoscopy (eg, comorbidities, obesity, older age, etc).
Patient preparation
Diet — Patients should follow preoperative fasting guidelines as they would for any type of anesthetic (table 2). Specifically, the American Society of Anesthesiologists (ASA) guidelines state that patients should fast for a minimum of two hours after ingestion of clear liquids and six hours after ingestion of light meals before sedation is administered. [6]. The period of fasting may need to be longer if there is known or suspected delayed gastric emptying [2]. In emergency situations that cannot be delayed, the airway may need to be protected by endotracheal intubation. (See "Gastrointestinal endoscopy in adults: Procedural sedation administered by endoscopists" and "Adverse events related to procedural sedation for gastrointestinal endoscopy in adults" and "Sedation-free gastrointestinal endoscopy".)
Medications
General guidance — Most medications can be continued up to the time of endoscopy and are usually taken with a small sip of water. The morning doses of some medications may need to be adjusted prior to upper endoscopy, such as medications for diabetes, due to decreased oral intake around the time of the procedure.
Antithrombotics — Decisions regarding the management of antiplatelet agents or anticoagulants must take into account the risk of bleeding engendered by maintaining the patient on the agent through the procedure and the risk of a thromboembolic event if the agent is discontinued in the periprocedural period [7]. In general, aspirin and nonsteroidal anti-inflammatory drugs can be continued safely in patients having an upper endoscopy. (See "Management of anticoagulants in patients undergoing endoscopic procedures" and "Management of antiplatelet agents in patients undergoing endoscopic procedures" and "Gastrointestinal endoscopy in patients with disorders of hemostasis".)
Antibiotic prophylaxis — As the risk of infection related to routine diagnostic upper endoscopy is low, antibiotic prophylaxis is generally not recommended. However, antibiotic prophylaxis for an upper endoscopy is recommended for patients with one of the following:
●Patients with cirrhosis undergoing endoscopy for an acute gastrointestinal (GI) bleed
●Prior to percutaneous endoscopic gastrostomy/jejunostomy tube placement
●Patients with severe neutropenia (absolute neutrophil count <500 cells/mm3) or advanced hematologic malignancies who are undergoing procedures associated with a high risk of bacteremia (eg, dilation of esophageal strictures, endoscopic sclerotherapy) [8] (table 3 and table 4) (see "Antibiotic prophylaxis for gastrointestinal endoscopic procedures")
Preprocedure testing in selected patients — It is generally recommended that patients not undergo routine preprocedure laboratory testing, chest radiography, or electrocardiography [9]. Instead, preprocedure testing should be used selectively based on the patient's medical history, physical examination findings, and procedural risk factors.
Our recommendations are consistent with 2014 guidelines from the American Society for Gastrointestinal Endoscopy (ASGE) that recommend preprocedure testing in the following settings [9]:
Laboratory studies
●Pregnancy testing for females of childbearing potential who provide an uncertain pregnancy history or who have a history suggestive of a current pregnancy (particularly if fluoroscopy is going to be used).
●Coagulation studies for patients with active bleeding, a known or suspected bleeding disorder (including a history of abnormal bleeding), an increased risk of bleeding due to medication use (eg, ongoing anticoagulant use, prolonged antibiotic use), prolonged biliary obstruction, malnutrition, or other conditions associated with acquired coagulopathies. For patients taking vitamin K antagonists (eg, warfarin), we check an international normalized ratio (INR) prior to the procedure. We do not check coagulation studies for patients who are receiving direct oral anticoagulants if the medication has been held for an appropriate amount of time prior to the procedure (algorithm 1) [10]. (See "Management of anticoagulants in patients undergoing endoscopic procedures", section on 'High or uncertain risk procedures'.)
●Hemoglobin/hematocrit for patients with pre-existing significant anemia or active bleeding, or if there is a high risk of significant blood loss during the procedure.
●Blood typing for patients with active bleeding, anemia, or low platelets who are likely to need a blood transfusion.
●Serum chemistry testing for patients with significant endocrine, renal, or hepatic dysfunction if medications are to be used that may further impair function.
Imaging — Chest radiograph for patients with new respiratory symptoms or decompensated heart failure.
Informed consent — Informed consent is obtained prior to all GI endoscopic procedures. Informed consent is a process that involves discussing the procedure (including administration of sedation) and the associated risks, benefits, alternatives, and limitations. (See "Informed procedural consent".)
PROCEDURE
Equipment — Routine upper endoscopy is performed using a high-definition white-light endoscope. In addition, multiple options are available to enhance visualization during endoscopy, though many require specialized equipment and training. (See "Magnification endoscopy" and "Chromoendoscopy" and "Confocal laser endomicroscopy and endocytoscopy" and "Barrett's esophagus: Evaluation with optical chromoscopy".)
Routine upper gastrointestinal (GI) endoscopy may be broken down into its component parts:
●Oral intubation with the endoscope
●Oropharyngeal examination
●Esophageal examination
●Examination of the esophagogastric junction (EGJ; also referred to as the gastroesophageal junction)
●Gastric examination, including retroflexion
●Traversing the pylorus
●Duodenal examination
●Tissue sampling
●Therapeutic maneuvers
Endoscopic technique
Patient position and topical anesthetic — For upper GI endoscopy, patients are typically placed on their left side with their neck flexed forward. A preprocedure simulation of the up and down maneuver that will be necessary to pass the endoscope from the mouth to the upper esophageal sphincter is recommended to assure proper orientation of all equipment.
Benzocaine spray or gel is used in some endoscopy centers for topical pharyngeal anesthesia. However, it may not improve patient tolerance of the procedure when intravenous sedation is also being used, and it is rarely associated with methemoglobinemia [11]. (See 'Complications' below and "Methemoglobinemia", section on 'Topical anesthetics'.)
Insertion and esophageal intubation — The upper endoscope is introduced into the mouth under direct visualization, allowing for limited visualization of the tongue, other structures in the mouth, and ultimately the hypopharynx. The endoscopist can often view the epiglottis, the vocal cords, both piriform sinuses, and the arytenoid cartilages (picture 1). In patients at risk for squamous neoplasia, particular attention should be given to both raised lesions and flat areas of discoloration with sharp borders in the oropharynx, as well as during inspection of the squamous esophagus below [12].
The cricopharyngeus muscle and esophageal orifice appear below the opening to the trachea, seemingly between the piriform sinuses. The endoscope is passed posteriorly toward the upper esophageal sphincter, which is at the level of the thyroid cartilage, 15 to 18 cm from the incisors. The upper esophageal sphincter is passed under direct visualization, often with the assistance of insufflation, a gentle chin lift, and slight application of pressure. We use only CO2 gas to insufflate the lumen of the GI tract for inspection, rather than air, to decrease the incidence of overdistension and its accompanying discomfort.
Esophageal intubation should be done slowly and gently, in part to avoid intubation of a Zenker's diverticulum since doing so can lead to a perforation. A Zenker's diverticulum is an outpouching of the posterior oropharynx just proximal to the upper esophageal sphincter caused by decreased compliance of the upper esophageal sphincter. Care must also be taken in patients with known or suspected proximal esophageal strictures, which can make esophageal intubation difficult and can increase the risk of perforation. (See "Zenker's diverticulum".)
Esophagus and esophagogastric junction — Following intubation of the esophagus, the tubular esophagus is examined. The esophagus is typically approximately 25 cm in length. The esophagus is examined both on insertion of the scope and on withdrawal of the instrument after inspection of the stomach and duodenum. Withdrawal should be carried out slowly and with adequate CO2 insufflation to ensure complete visualization.
The EGJ is generally approximately 40 cm from the incisors. There are both anatomic and histologic markers that separate the esophagus from the stomach. However, landmarks differentiating the esophagus from the stomach may be difficult to identify due to movement of the esophagus and stomach during the examination. The top of the gastric folds is the landmark generally believed to represent the EGJ. In patients without Barrett's esophagus, this is also the area of the squamocolumnar junction. The squamocolumnar junction is the area where the squamous epithelial lining of the esophagus meets the columnar lining of the stomach. Because this transition from squamous to columnar epithelium is typically uneven around the circumference of the lumen, it is also referred to as the Z-line. The transition from squamous to columnar epithelium results in a color change. The columnar mucosa of the stomach is salmon colored, whereas the squamous mucosa is pale pink (picture 2). In patients without a hiatus hernia, the EGJ also corresponds with the lower esophageal sphincter, though the lower esophageal sphincter is extrinsic and cannot be seen endoscopically. (See "Hiatus hernia", section on 'Anatomy and physiology of the gastroesophageal junction'.)
Important features include the color of the mucosa and evidence of erythema, erosions, ulcers, strictures, rings, webs, varices, or diverticula. Hiatus hernias are frequently identified during upper endoscopy. A hiatus hernia is a condition where some portion of the stomach has herniated through the esophageal hiatus in the crural diaphragm. In this situation, the columnar-lined mucosa and top of the gastric folds will be seen proximal to the extrinsic narrowing of the lumen caused by the diaphragmatic pinch. Hiatus hernias may be seen during retroflexed examination of the stomach as well. (See "Hiatus hernia", section on 'Upper endoscopy'.)
Stomach — The stomach is entered after passing the region of the EGJ. Initial visualization is usually of the relatively large folds of the greater curvature of the stomach (picture 3). The examination usually proceeds along the greater curvature of the stomach towards the pylorus (figure 1).
Certain techniques improve examination of the stomach and minimize the risk of complications. These include:
●Insufflation of the stomach – The stomach should be insufflated to allow for inspection, but excessive insufflation should be avoided as gastric distension can induce retching or belching.
●Suctioning fluid in the fundus – The pool of gastric fluid in the fundus seen upon entering the stomach should be suctioned. This improves visualization of the area and minimizes the risk of reflux of gastric fluid and possible aspiration. However, care should be taken to avoid applying suction to the mucosa, as doing so may create suction artifacts that appear as abnormal mucosa. In addition, since any contact between the endoscope and the mucosa can result in trauma, it is best to examine the mucosa throughout the upper GI tract while avoiding contact with the mucosa.
●Inspection – While all areas of the stomach should be carefully examined, particular attention should be paid to the incisura, which is an area of the angularis along the lesser curvature.
●Retroflexion – Adequate visualization of the proximal stomach and EGJ is achieved through retroflexion. Retroflexion allows the endoscopist to see areas that are not well visualized during the initial direct examination (figure 2). The technique involves the following:
•Distending the stomach with CO2.
•Advancing the endoscope to the region of the angularis on the lesser curvature in the antrum or the distal gastric body.
•Turning the endoscope up-down dial to the maximal up position to achieve a 140- to 160-degree bend at the tip of the endoscope.
•Locking the wheels of the endoscope to increase stiffness of the tip of the endoscope.
•Withdrawing the endoscope to pull the tip of the endoscope toward the EGJ (picture 4).
•Rotating the endoscope to obtain a 360-degree view of the upper stomach.
Hiatus hernias are particularly easy to see when the endoscope is in the retroflexed position (picture 5). It is important to note that items placed through the endoscope's accessory channel, such as a biopsy forceps, may be difficult to use when the endoscope is in the retroflexed position, and thus may need to be passed to the tip of the instrument before retroflexion is performed. In addition, care is required to ensure that the retroflexed endoscope does not become entrapped within a hiatus hernia or in the esophagus. This is normally done by making sure that the retroflexed endoscope is not pulled into the hernia or the esophagus.
Pyloric intubation — The pylorus is traversed under direct visualization (picture 6). Opening the pylorus for passage of the endoscope sometimes requires insufflation, gentle pressure, and patience in patients who have particularly active or motile pyloric regions.
In patients with a "J-shaped" stomach, intubating the pylorus may be difficult as extreme angulation of the endoscope may be required. Attempts to traverse the pylorus in such patients may result in significant looping in which the shaft of the endoscope presses on the greater curvature of the stomach. The pressure applied to the gastric wall by the loop can result in patient discomfort. In such circumstances, removing air from the stomach or application of external pressure on the abdominal wall in the left upper quadrant may help with passage of the endoscope through the pylorus.
Duodenum — After passing through the pylorus, the endoscope enters the duodenal bulb. The endoscope is then advanced through the duodenal sweep and into the second portion of the duodenum. The duodenal bulb is often devoid of characteristic features, though there may be raised bumps and polypoid areas representing either prominent Brunner's glands or heterotopic foci of gastric mucosa. The duodenum distal to the bulb has distinctive circular rings called valvulae conniventes (picture 7).
The ampulla of Vater is found in the second portion of the duodenum and is the site where the common bile duct and pancreatic duct empty into the duodenum. While the ampulla may be seen with a standard forward-viewing endoscope, a more complete examination of the ampulla requires the use of a side-viewing duodenoscope (the same endoscope used for endoscopic retrograde cholangiopancreatography). This is not done routinely as part of an upper endoscopy and requires specialized skills and equipment. However, it may be required for some patients, such as those with familial adenomatous polyposis, who are undergoing screening for ampullary adenomas. If examination of the ampulla is required, the examination should be performed with an endoscopist who is trained in the use of a side-viewing duodenoscope. (See "Familial adenomatous polyposis: Screening and management of patients and families", section on 'Screening'.)
Diagnostic and therapeutic maneuvers — A variety of diagnostic and therapeutic maneuvers can be carried out during upper endoscopy. The most common diagnostic maneuver is tissue sampling.
Tissue sampling methods — Tissue sampling is an important part of many upper endoscopic procedures [13,14]. Specimens obtained during procedures can be sent for histologic, cytologic, or microbiologic analysis, depending on the type of sample and clinical indication for tissue sampling. When submitting samples, it is helpful to provide the pathologist, cytologist, or microbiologist with details such as the clinical history, specimen-specific location and appearance, and the question to be answered. Including the endoscopy report and photographs of the area in question can also provide useful clinical context.
●Biopsy – A biopsy forceps is placed though the accessory channel of the endoscope and advanced to the target area, and the forceps is opened and closed to obtain a pinch biopsy. Many forceps have a "spike" that allows for the acquisition of more than one sample per pass of the forceps.
The tubular esophagus may be difficult to biopsy because the forceps comes out of the accessory channel parallel to the wall of the esophagus. This problem can be solved by the "turn-in" technique, where the tip of the endoscope is turned to be more perpendicular to the wall of the esophagus (or anywhere in the upper GI tract where this is an issue), allowing for a more direct angle in which to obtain a biopsy. This technique may be augmented by suctioning of the mucosa into the biopsy forceps, which is opened close to the tip of the endoscope before tissue acquisition, allowing for a larger sample to be obtained with each "bite" of the biopsy forceps.
Typically, biopsy forceps can only sample mucosal lesions. If a submucosal lesion is encountered, it may be possible to perform stacked or tunneled biopsies in which the same location is biopsied multiple times with the hope of obtaining deeper samples. This frequently is unsuccessful and increases the risk of perforation (especially in the esophagus), so it should be done with extreme caution. Submucosal lesions typically require assessment by endoscopic ultrasound to fully characterize and to provide tissue samples if indicated.
When urgent diagnosis of suspected cancer is needed in a hospital setting, endoscopic forceps biopsies can be processed by frozen section or by smashing small specimens for immediate cytology preparation. This may save time and avoid repeat procedures if delayed processed biopsies are negative [15].
●Brushings – A brush within a sheath is placed through the accessory channel of the endoscope and advanced to the target area. The brush head is advanced out of the sheath, and the endoscopist gently brushes the area of interest.
●Polypectomy – Polypectomy is carried out in a manner similar to that used during colonoscopy. Small polyps may be removed using a biopsy forceps. Larger polyps can be removed using snares that are passed down the accessory channel of the endoscope. Lesions larger than approximately 2 cm may require removal using specialized techniques. (See "Overview of endoscopic resection of gastrointestinal tumors", section on 'Endoscopic resection techniques'.)
●Full-thickness gastric biopsy – Using a specialized over-the-scope metal clip with a built-in snare, a full-thickness biopsy may be obtained to assess submucosal lesions and nerve plexus. (See "Endoscopic clip therapy in the gastrointestinal tract: Bleeding lesions and beyond", section on 'Uses for over-the-scope endoscopic clips'.)
Other interventions — Other diagnostic and therapeutic interventions that can be performed include:
●Endoscopic hemostasis (see "Overview of the treatment of bleeding peptic ulcers", section on 'Endoscopic therapy' and "Methods to achieve hemostasis in patients with acute variceal hemorrhage", section on 'Initial management' and "Angiodysplasia of the gastrointestinal tract", section on 'Endoscopic treatment' and "Argon plasma coagulation in the management of gastrointestinal hemorrhage" and "Endoscopic clip therapy in the gastrointestinal tract: Bleeding lesions and beyond" and "Mallory-Weiss syndrome", section on 'Treatment of persistent and recurrent bleeding')
●Dilation of esophageal strictures, gastric outlet stenoses, and anastomotic strictures (see "Endoscopic interventions for nonmalignant esophageal strictures in adults" and "Gastric outlet obstruction in adults", section on 'Management' and "Gastrointestinal endoscopy in patients who have undergone bariatric surgery", section on 'Stomal (anastomotic) stenosis')
●Stent placement for benign or malignant disease (see "Endoscopic stenting for palliation of malignant esophageal obstruction" and "Endoscopic palliation of esophageal cancer" and "Enteral stents for the palliation of malignant gastroduodenal obstruction")
●Ablation of Barrett's esophagus (see "Barrett's esophagus: Treatment with radiofrequency ablation")
●Endoscopic mucosal resection of gastrointestinal tumors (see "Overview of endoscopic resection of gastrointestinal tumors")
●Percutaneous endoscopic gastrostomy tube placement (see "Gastrostomy tubes: Complications and their management")
●Foreign body removal (see "Ingested foreign bodies and food impactions in adults" and "Foreign bodies of the esophagus and gastrointestinal tract in children")
●Pneumatic dilation, botulinum toxin injection, or peroral endoscopic myotomy (POEM) (see "Pneumatic dilation and botulinum toxin injection for achalasia")
●Placement of a wireless video capsule (see "Wireless video capsule endoscopy", section on 'Capsule ingestion')
●Placement of esophageal acid monitoring devices (see "Clinical manifestations and diagnosis of gastroesophageal reflux in adults", section on 'Ambulatory esophageal pH monitoring')
●Endoscopic therapy for gastroesophageal reflux (see "Radiofrequency treatment for gastroesophageal reflux disease")
●Endoscopic treatment of a Zenker's diverticulum (see "Zenker's diverticulum", section on 'Flexible endoscopy')
Interventions for limited visualization — Visualization during upper GI endoscopy may be hindered due to several reasons.
●Excessive motility – Excessive motility in the stomach or small bowel may make careful examination difficult. While patience may be all that is necessary to allow the bowel to "quiet" and allow the entire examination to be completed, the use of medications to slow the bowel, including glucagon (0.5 mg intravenously [IV]), is an option. This may be particularly helpful when therapeutic maneuvers are being carried out (eg, argon plasma coagulation of an angiodysplasia).
●Foam and mucus – The use of an irrigating syringe or irrigating device is often sufficient to clear away bubbles and excessive mucus that are obscuring the view of portions of the upper GI tract during endoscopy. If irrigation is unsuccessful, agents that lower the surface tension of bubbles (eg, simethicone) and mucolytic agents (eg, N-acetylcysteine) may be used [16].
●Retained debris – Residual gastric contents not only impede complete visualization but also increase the risk of aspiration. Irrigation is insufficient to remove small residual gastric material. Specialized suction devices are also available to help clear the stomach in the setting of upper GI bleeding. Prokinetic agents (eg, erythromycin) administered prior to endoscopy may facilitate passage of retained debris or blood. (See "Approach to acute upper gastrointestinal bleeding in adults", section on 'Prokinetics'.)
●Altered anatomy – Abnormal anatomy (eg, a paraesophageal hernia) or surgically altered anatomy (eg, bariatric surgery) may make completion of upper endoscopy more difficult. Specific maneuvers, such as changing the patient's position or the application of external abdominal pressure to "splint" the stomach, may facilitate instrument passage in some situations. (See 'Pyloric intubation' above and "Gastrointestinal endoscopy in patients who have undergone bariatric surgery".)
Quality indicators — A number of quality indicators for upper endoscopy have been proposed, of which some have been designated priority quality indicators [17-19].
●Inspection time – Inspection of the esophagus, stomach and duodenum should last for at least seven minutes from intubation to extubation in a diagnostic examination in a patient who has not undergone an upper endoscopy within the last three years [20,21]. A slower, more careful examination has been shown to identify more pathology. In patients with Barrett's esophagus, for example, a longer inspection time has been associated with a higher rate of dysplasia detection [22].
●Photodocumentation and reporting – All endoscopic procedures should include a complete report detailing the extent of the tissue examined and all normal and abnormal findings encountered. Photodocumentation greatly enhances the record and should be included [20,23]. In 2015, the European Society of Gastrointestinal Endoscopy (ESGE) recommended that the endoscopist take at least 10 photos during an upper endoscopy to include the following locations: proximal esophagus, distal esophagus, Z-line and diaphragm indentation, cardia and fundus in inversion, corpus in forward view including lesser curvature, corpus in retroflex view including greater curvature, angulus in partial inversion, antrum, duodenal bulb, and second part of duodenum. Additional images have been suggested in higher-risk patients being screened for gastric cancer [24]. Images of any abnormalities found during upper endoscopy should be documented.
●Additional metrics – Additional priority indicators (American Society for Gastrointestinal Endoscopy/American College of Gastroenterology/American Gastroenterological Association) include the following unless contraindicated [23]:
•Endoscopic treatment of ulcers with active bleeding or with nonbleeding visible vessels (target greater than 98 percent).
•Plans for assessing Helicobacter pylori infection for patients diagnosed with gastric or duodenal ulcers are documented (target greater than 98 percent).
•Administration of prophylactic antibiotics in patients with cirrhosis with acute upper GI bleeding before esophagogastroduodenoscopy (EGD; target greater than 98 percent).
•Use of proton pump inhibitors for suspected peptic ulcer bleeding (target greater than 98 percent).
COMPLICATIONS — Serious complications of upper endoscopy are rare. The overall complication rate of upper gastrointestinal (GI) endoscopy is 0.15 percent [25,26]. Complication rates are lower for diagnostic endoscopy without therapeutic maneuvers at 0.0002 percent [27].
●Cardiopulmonary complications – Cardiopulmonary complications can result from procedural sedation. The overall incidence of cardiopulmonary complications is low. In a prospective survey of 14,149 upper endoscopies and a retrospective study of 21,011 endoscopic procedures, the rates of early cardiopulmonary events were 2 to 5.4 per 1000 cases, and mortality rates, which included cases of aspiration pneumonia, pulmonary embolism, and myocardial infarction, were 0.3 to 0.5 per 1000 cases [28,29]. (See "Adverse events related to procedural sedation for gastrointestinal endoscopy in adults".)
Risk factors for the development of cardiopulmonary complications of endoscopy include advanced age, underlying comorbid illness (especially pulmonary disease), dementia, anemia, obesity, and endoscopy performed for emergency indications [3]. Adverse events resulting from oversedation include hypoxemia, hypoventilation, airway obstruction, hypotension, vasovagal episodes, arrhythmias, and aspiration. The frequency of such unplanned cardiopulmonary events has been shown to be associated with increasing American Society of Anesthesiologists (ASA) scores (table 5) [3]. (See "Preoperative evaluation for anesthesia for noncardiac surgery", section on 'ASA physical status'.)
●Methemoglobinemia – Topical anesthetics such as benzocaine are a common cause of methemoglobinemia. Methemoglobinemia may be clinically suspected in this setting by the presence of cyanosis or hypoxia that does not resolve with oxygen supplementation. Patients have a normal arterial PO2 (PaO2) obtained by arterial blood gas assessment, and/or the presence of dark red or brownish to blue blood. (See "Methemoglobinemia".)
Methemoglobin is an altered state of hemoglobin in which the ferrous (Fe2+) irons of heme are oxidized to the ferric (Fe3+) state. The ferric hemes of methemoglobin are unable to bind oxygen. In addition, the oxygen affinity of any accompanying ferrous hemes in the hemoglobin tetramer is increased [30]; as a result, the oxygen dissociation curve is "left-shifted," and oxygen delivery to the tissues is impaired. The diagnosis and management of methemoglobinemia are discussed in detail separately. (See "Methemoglobinemia".)
●Bleeding – Bleeding rarely occurs following diagnostic upper endoscopy. While the risk may be increased in patients with thrombocytopenia or coagulopathies, diagnostic upper endoscopy is generally thought to be safe in patients with platelet counts as low as 20,000/microL [31]. The risk of bleeding is increased with therapeutic maneuvers such as esophageal dilation, percutaneous endoscopic gastrostomy tube placement, or endoscopic mucosal resection. (See "Complications of endoscopic esophageal stricture dilation", section on 'Hemorrhage' and "Overview of endoscopic resection of gastrointestinal tumors", section on 'Adverse events' and "Gastrostomy tubes: Complications and their management", section on 'Bleeding' and "Gastrointestinal endoscopy in patients with disorders of hemostasis".)
●Perforation – Upper endoscopy is the most common cause of esophageal perforation. It is more common when therapeutic maneuvers are carried out and in patients with esophageal diverticula. The estimated risk of esophageal perforation varies with the procedure being performed [32]:
•Diagnostic endoscopy with a flexible endoscope: 0.03 percent
•Stricture dilation: 0.09 to 2.2 percent
•Sclerotherapy: less than 1 percent
•Pneumatic dilation for achalasia: 2 to 6 percent
The diagnosis and management of esophageal perforations is discussed elsewhere. (See "Complications of endoscopic esophageal stricture dilation" and "Complications of endoscopic esophageal stricture dilation", section on 'Esophageal perforation' and "Surgical management of esophageal perforation".)
●Infection – The risk of infection related to GI endoscopy is low, though there have been cases of hepatitis B, hepatitis C, and bacterial transmission related to breaches in protocols for proper endoscope disinfection. (See "Preventing infection transmitted by gastrointestinal endoscopy" and 'Antibiotic prophylaxis' above and "Antibiotic prophylaxis for gastrointestinal endoscopic procedures".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)
●Basics topics (see "Patient education: Upper endoscopy (The Basics)")
●Beyond the Basics topics (see "Patient education: Upper endoscopy (Beyond the Basics)")
SUMMARY AND RECOMMENDATIONS
●Procedure – Upper endoscopy (esophagogastroduodenoscopy [EGD]) includes visualization of the oropharynx, esophagus, stomach, and proximal duodenum, with real-time assessment and interpretation of the findings encountered. Routine upper endoscopy is performed using a high-definition white-light endoscope. (See 'Equipment' above.)
●Patient selection – Upper gastrointestinal (GI) endoscopy is indicated in the diagnostic evaluation of signs and symptoms of a wide variety of GI disorders as well as for therapeutic interventions (table 1). (See 'Indications' above.)
●Contraindications – Relative contraindications for upper GI endoscopy include:
•Patients who cannot tolerate moderate sedation, monitored anesthesia care (MAC), or general anesthesia in whom unsedated upper endoscopy is not feasible.
•Patients who are hemodynamically unstable.
•Patients with GI obstruction.
•Patients with severe coagulation abnormalities (platelet count ≤20,000/microL), particularly if biopsies or therapeutic maneuvers are anticipated. (See 'Contraindications' above.)
●Presedation assessment – Patients require a presedation evaluation to identify underlying conditions that may increase risk and to create a plan for procedural sedation that minimizes risk while managing coexisting medical conditions. (See 'Presedation assessment' above.)
●Patient preparation – Prior to elective upper GI endoscopy, patients should fast for a minimum of two hours after ingestion of clear liquids and six to eight hours after ingestion of light meals, and sometimes longer if there is known or suspected delayed gastric emptying. Most medications can be continued up to the time of endoscopy and are usually taken with a small sip of water. The morning doses of some medications may need to be adjusted prior to upper endoscopy, such as medications for diabetes. The decision of whether to stop antiplatelet agents or anticoagulants must take into account the procedure-related risk of bleeding and the risk of periprocedural thrombosis. Antibiotic prophylaxis is only indicated in selected patients undergoing upper endoscopy (table 3 and table 4). (See 'Patient preparation' above.)
●Preprocedure testing – Preprocedure testing is not routinely required in all patients and should be used selectively based on the patient's medical history, physical examination findings, and procedural risk factors. (See 'Preprocedure testing in selected patients' above.)
●Complications – Complications of upper endoscopy include complications due to sedation, related to the endoscopy, and complications related to diagnostic and therapeutic maneuvers. (See 'Complications' above.)
