Esophagogastroduodenoscopy or colonoscopy
Insufficient data (endoscopist’s discretion)
Esophagogastroduodenoscopy or colonoscopy
Not recommended
Antibiotic prophylaxis
The role of preprocedure antibiotics to prevent endocarditis or bacteremia in patients with vascular or other prostheses is undefined. Based on the documented risks of bacteremia with given procedures and the risks of establishing an infection in certain pre-existing conditions, the American Society of Gastrointestinal Endoscopy promotes guidelines for antibiotic prophylaxis before endoscopic procedures (Table 16.1). In many circumstances, no definitive recommendations can be made and the decision is made at the clinician’s discretion. Antibiotics can be costly, and many have a substantial risk of allergic reactions. These issues must be considered when contemplating the use of prophylactic antibiotics.
Coagulation disorders
Although coagulation abnormalities are not absolute contraindications to endoscopy, the use of endoscopic biopsy can be associated with an increased risk of bleeding. Before any therapeutic intervention, including percutaneous gastrostomy tube placement and electrocoagulation for polypectomy or hemostasis, attempts should be made to correct coagulation disorders. Prolongation of prothrombin time unrelated to the administration of warfarin may require parenteral vitamin K therapy. If there is no response to vitamin K or if emergency therapy is necessary, coagulation factors should be supplemented with fresh-frozen plasma. Antiplatelet agents (e.g. aspirin) should ideally be withheld for 7–10 days before and after these therapeutic measures, although there is no evidence that routine endoscopy including polypectomy is associated with an increased risk of bleeding complications in patients using daily aspirin. Depending on the underlying medical condition, warfarin can often be withheld for 5–7 days before the procedure and reinstituted 1–2 days after therapy.
If medical conditions prohibit discontinuation, one of two potential management pathways can be used. In the first, the patient is hospitalized, warfarin is discontinued, and heparin is initiated. When the prothrombin time normalizes, the patient is prepared for the procedure, and heparin is discontinued 4 h before the intervention. Heparin can be restarted 4 h after the procedure, and warfarin can be reinstituted 12–24 h after heparin if no procedure-related hemorrhage occurs. Alternatively, warfarin may be stopped 5 days prior to the procedure and subcutaneous low molecular weight heparin (e.g. dalteparin) initiated, once or twice daily, according to the patient’s weight. The last low molecular weight heparin dose is given the night before the procedure and then restarted the evening of the procedure and continued for 5 days, whereas warfarin is restarted the evening of the procedure and continued as previously taken. This second approach avoids hospitalization because the subcutaneous low molecular weight heparin is self-administered in an outpatient setting.
Upper gastrointestinal endoscopy
Indications and contraindications
Many symptoms attributable to diseases of the esophagus, stomach, and duodenum are best assessed by esophagogastroduodenoscopy (EGD) or upper gastrointestinal endoscopy. The American Society of Gastrointestinal Endoscopy has established consensus guidelines for the appropriate use of EGD (Table 16.2). Therapeutic endoscopy is often indicated for control of variceal and nonvariceal bleeding, dilation of strictures, removal of some foreign bodies, palliation of advanced malignancies with stents or tumor ablation, and placement of a percutaneous gastrostomy tube. The advent of longer endoscopes has expanded the capability of upper gastrointestinal endoscopy in diagnosing and potentially treating diseases of the small intestine. Enteroscopy is indicated when investigating chronic bleeding presumed secondary to a source in the small intestine or if visualization or sampling the small intestine is warranted by radiological abnormalities.
Table 16.2 Indications for upper gastrointestinal endoscopy
| Diagnostic Upper abdominal distress despite an appropriate trial of therapy Upper abdominal distress associated with signs or symptoms of organic disease (weight loss, anorexia) Refractory vomiting of unknown cause Dysphagia or odynophagia Esophageal reflux symptoms unresponsive to therapy Upper gastrointestinal bleeding When sampling of duodenal or jejunal tissue or fluid is indicated To obtain a histological diagnosis for radiographically demonstrated gastric or esophageal ulcers, upper intestinal tract strictures, or suspected neoplasms To screen for varices so that patients with cirrhosis can be identified as possible candidates for prophylactic medical or endoscopic therapy To assess acute injury after caustic ingestion When management of other disease processes is affected by the presence of upper gastrointestinal pathological conditions (e.g. use of anticoagulants) Therapeutic Treatment of variceal and nonvariceal upper gastrointestinal bleeding Removal of foreign bodies Removal of selected polypoid lesions Dilation of symptomatic strictures Palliative treatment of stenosing neoplasms Placement of percutaneous feeding gastrostomy tube Surveillance Follow-up of selected gastric, esophageal, or stomal ulcers to document healing Barrett esophagus Familial adenomatous polyposis Adenomatous gastric polyps Follow-up of varices eradicated by endoscopic therapy |
The major contraindications to upper gastrointestinal endoscopy include perforation, hemodynamic instability, cardiopulmonary distress, and inadequate patient co-operation. Coagulation disorders are relative contraindications to therapeutic intervention. Percutaneous gastrostomy tube placement is contraindicated if the stomach is inaccessible because of a prior gastrectomy or interposed bowel, liver, or spleen.
Patient preparation and monitoring
Patients should not ingest solid food for 6–8 h or liquids for 4 h before elective upper gastrointestinal endoscopy. If delayed gastric emptying is suspected, a liquid diet can be instituted 24 h before the procedure and the fasting interval increased to 8–12 h. For complete gastric outlet obstruction, evacuation of the stomach with a nasogastric tube is usually necessary. If an emergency endoscopic procedure is required for gastrointestinal bleeding, measures should be taken to avoid aspiration. Evacuation of the stomach with an orogastric tube before the procedure, attentiveness to oral suction during the procedure, and prophylactic endotracheal intubation in an obtunded patient protect the patient’s airway.
Conscious sedation is typically performed using a combination of a short-acting benzodiazepine (e.g. midazolam) along with a short-acting opiate (e.g. fentanyl), although the synergistic cardiopulmonary depressant effects of this combination may increase the rate of cardiopulmonary complications. Throughout the procedure, a trained assistant should work together with the endoscopist to monitor the oral secretions as well as the overall clinical condition of the patient.
Performance of the procedure
The endoscope is introduced blindly or under direct visualization by passing the instrument into the posterior pharynx and instructing the patient to swallow. Direct visualization is preferred because it is less traumatic and provides a view of the larynx. A standard EGD involves a complete inspection of the esophagus, stomach, and the first two portions of the duodenum. A pediatric colonoscope or push enteroscope can be advanced into the proximal jejunum. Enteroscopy can also be performed with the sonde enteroscope, which relies on peristaltic movement to propel the instrument into the distal jejunum or ileum, but this instrument does not provide biopsy or therapeutic capabilities.
Endoscopic biopsy or brush cytology studies may provide a pathological diagnosis. For some disease processes (e.g. infections caused by Helicobacter pylori and causes of malabsorption in the small intestine), random biopsies of normal-appearing mucosa may be indicated. Upper gastrointestinal endoscopy also provides the capability of therapeutic intervention. Dysphagia from esophageal strictures or achalasia can be relieved with endoscopic dilation using pneumatic balloon or sequential bougienage techniques. The safest means of bougienage dilation involves passage of the dilator over a guidewire placed endoscopically into the distal stomach. Although fluoroscopy reduces the complication rate of dilation, radiation exposure and resource limitations have precluded its routine use in many centers. Acute or chronic nonvariceal hemorrhage can be controlled with electrocoagulation, heater probe application, injection therapy, or laser photocoagulation. Large or bleeding esophageal varices may be treated with injection sclerotherapy or band ligation. Mucosal polyps can be excised with electrocoagulation using hot biopsy forceps or with snare polypectomy. Deep tissue sampling and excision of mucosal lesions may be accomplished with submucosal injection and endoscopic mucosal resection (EMR). Large stenosing esophageal or gastric malignancies can be ablated with laser photocoagulation or electrocoagulation. Esophageal malignancies can also be palliated by deploying metallic expandable stents.
Complications
Diagnostic upper gastrointestinal endoscopy is usually very safe, and rates of serious complications are low. Most complications are related to oversedation, emphasizing the need for preprocedural patient assessment and vigilant patient monitoring throughout the period of sedation. The high rate of wound infections associated with gastrostomy tube placement can be substantially reduced by prophylactic antibiotics. The benefit of prophylactic antibiotics for other indications remains unproven.
Video capsule endoscopy
Indications and contraindications
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