11.9 Gastroesophageal Reflux Disease
Gastroesophageal reflux disease (GERD) occurs when stomach contents flow backwards into the esophagus. GERD is a common, chronic disorder that develops in about 20% of adults in the United States.[1] Please see Figure 11.30[2] for an image of what occurs with GERD.
GERD can be classified into three different types, based on whether or not damage is occurring to the esophagus: nonerosive reflux disease (no damage to the esophagus), erosive esophagitis (formation of ulcers or erosions in the esophagus), and Barrett’s esophagus. Barrett’s esophagus is further described in the “Pathophysiology” subsection.[3]
Common risk factors for the development of GERD include the following[4]:
- Poor muscle tone in the lower esophageal sphincter
- Hiatal hernia
- Slow gastric contents emptying
- Obesity
- Hiatal hernia
- Age over 50 years old
- Tobacco usage
- Excessive alcohol use
- Pregnancy
- Low socioeconomic status
- Medications such as calcium channel blockers, anticholinergics, benzodiazepines, NSAIDs/aspirin, some antidepressants, albuterol, and nitroglycerin
Pathophysiology
There are several abnormalities that can cause GERD, such as impaired lower esophageal sphincter (LES) tone, the presence of a hiatal hernia, impaired esophageal mucosa, and altered esophageal peristalsis.[5]
The LES is a ring of smooth muscle located between the esophagus and stomach to prevent backward flow of stomach contents. In clients who do not have GERD, the LES is a high-pressure area that only opens when food is present, allowing food to flow to enter the lower pressure area of the stomach. However, in clients with GERD, the LES may inappropriately relax, allowing stomach contents to flow backwards into the esophagus.[6]
A hiatal hernia is a condition in which the upper part of the stomach abnormally bulges through the hiatus of the diaphragm. When there is laxity in this hiatus, gastric content can back up into the esophagus.[7] Read more about hiatal hernias in the “Hernia” section of this chapter.
Esophageal mucosa normally functions as a protective defensive barrier against acid gastric contents, but with repeated exposure to stomach contents (which are highly acidic), the mucosa can become damaged. Clients with chronic GERD can develop Barrett’s esophagus. Chronic exposure to acidic stomach contents causes squamous epithelial cells that line the esophagus to transition into columnar epithelium, also known as Barrett’s epithelium. Barrett’s epithelium is more resistant to acid exposure but can become cancerous. Therefore, Barrett’s esophagus is considered a precancerous condition that is closely monitored.[8],[9]
Normally, the acidic gastric contents that enter the esophagus are cleared by frequent esophageal peristalsis and neutralized by salivary bicarbonate. Clients with GERD may have impaired esophageal peristalsis, leading to decreased clearance of gastric contents, resulting in reflux symptoms and mucosal damage.[10]
Assessment