Indications and Contraindications

Upper gastrointestinal endoscopy, known also as upper GI endoscopy or esophagogastroduodenoscopy (EGD), is the method of choice for examining the esophagus, stomach, and duodenum. In one sitting, it permits the gross visual inspection of the upper gastrointestinal tract, the collection of tissue and fluid samples, as well as elective and emergency therapeutic interventions. It can be performed quickly and safely with good patient tolerance and without extensive patient preparations. The requirements in terms of equipment and operator proficiency are relatively modest.

Indications

Upper GI endoscopy has a broad range of indications. It is used to confirm or exclude a particular diagnosis in patients with upper gastrointestinal complaints, to monitor the progression of a known disease, and for staging in patients with a systemic disease (Fig. 1.1).

Contraindications

An absolute contraindication to elective upper GI endoscopy is lack of informed consent from a mentally competent patient. Relative contraindications are organ perforations and states of cardiac or respiratory decompensation (Fig. 1.2).

Risks and Complications: Cardiac and Pulmonary

The rate of serious complications in upper GI endoscopy is small and is measured in tenths of a percent (Table 1.1). Reports based on larger reviews show that the mortality rate is less than 0.01%.

It should be emphasized that most complications do not involve the gastrointestinal tract itself but consist of respiratory or cardiovascular incidents, especially in sick or sedated patients (Table 1.2).

Complications can result from local anesthesia, sedation, or the endoscopy itself. They consist mainly of respiratory and cardiovascular events, mechanical injuries, hemorrhages, and infections.

Local Anesthesia

Anesthetic throat sprays have the potential to incite an allergic reaction, produce cardiac side effects, and promote aspiration. The overall risk of complications from pharyngeal anesthesia is approximately 1:10 000. The risk of fatal complications is considerably lower.

Sedation and Analgesia

Benzodiazepines. The use of benzodiazepines is often associated with a decrease in arterial oxygen saturation, but this is rarely significant. The risk is increased in older patients, patients with chronic respiratory failure, coronary heart disease, or hepatic insufficiency, and in emergency endoscopy.

The principal risks are a fall in blood pressure and hypoxemia-induced cardiac arrhythmia. Myocardial infarctions during endoscopy are rare. Respiratory complications can range from hypoventilation to apnea. The most common problem is aspiration. Sedation is believed to be the principal risk factor for aspiration pneumonia.

Narcotics. The use of narcotic analgesics, such as Pethidine, can lead to hypotension and bradycardia.

Cardiac Complications

Approximately 50 % of the complications that occur in upper GI endoscopy are cardiac in nature. They consist of heart rate changes, arrhythmias, and repolarization abnormalities. The mortality rate of cardiac complications ranges from 1:20000 to 1:50 000.

Arrhythmias. The most common arrhythmias are tachycardia and extrasystoles, which usually have no clinical significance and are spontaneously reversible. Bradycardia is observed in fewer than 5 % of patients. Significant tachyarrhythmias are also rare.

Repolarization abnormalities. These occur predominantly in patients with coronary heart disease. They reflect a myocardial ischemia, usually clinically silent, that is caused by arterial hypoxia due to the increased cardiac work load.

Respiratory Complications

Respiratory complications consist of hypoventilation, apnea, and aspiration, usually in connection with premedication. Their overall incidence is low, however. The mortality rate is less than 1:50 000.

Risks and Complications: Gastrointestinal

Perforation and Bleeding

Although perforation and bleeding from gastroscopy are the complications that patients fear the most, they account for less than 10% of all complications in diagnostic endoscopy.

The most common sites of perforation, in descending order of frequency, are the esophagus, hypopharynx, duodenum, and stomach. Predisposing factors are diverticula, severe cervical spondylosis, and endoscopic interventions such as dilation, prosthesis insertion, and laser therapy (Fig. 1.3). Severe postbiopsy bleeding during or after endoscopy is rare.

Infection

The risk of clinically overt infection after upper GI endoscopy is extremely small, but does exist. Bacteremia is a common occurrence, however. Three factors are relevant in the pathogenesis of infection: the transmission of infectious organisms, the nature of the procedure, and patient-associated risks (Table 1.3).

Disease Transmission

The direct transmission of microorganisms from patient to patient by contaminated endoscopes has been described for Salmonellae, mycobacteria, Helicobacter pylori, hepatitis B virus, and other pathogens. The endoscopic transmission of HIV infection has not yet been definitely confirmed.

Bacteremia is not uncommon after endoscopy (up to 5 % of cases) but usually has no clinical significance. The endoscope itself can be a reservoir for pathogenic microorganisms (including pseudomonas). Potential sources of infection are contaminated water bottles and the endoscope channels that are more difficult to access and clean. Meticulous cleaning and disinfection after each endoscopy and before the first endoscopy of the day are essential elements of risk management.

Nature of the Procedure

It is clear that procedures that inflict mucosal injuries are associated with a higher infection risk than a simple, uncomplicated endoscopy. Antibiotic prophylaxis should be used liberally in cases deemed to be at risk.

Patient-Associated Risks

These risks consist mainly of cardiac anomalies, prosthetic valves, and immunosuppression. The regimen shown in Table 1.4 is recommended for general antibiotic prophylaxis but should be tailored to suit individual clinical requirements.