Peptic ulcer
Introduction
A peptic ulcer is a sore that develops on the lining of the stomach, upper small intestine, or esophagus. The most common types are gastric ulcers, which occur on the inside of the stomach, and duodenal ulcers, which occur on the inside of the upper portion of the small intestine (duodenum). Peptic ulcers are primarily caused by infection with the bacterium Helicobacter pylori (H. pylori) and the chronic use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen.
Pathophysiology
Peptic ulcers occur when the balance between the aggressive factors (acid and pepsin) and the defensive factors (mucus and bicarbonate secretion, prostaglandins, blood flow to the mucosa, and the regenerative capacity of the epithelium) is disrupted. The primary aggressive factors include gastric acid and pepsin, which can erode the mucosal lining if not adequately neutralized or if the mucosal defenses are compromised.
Role of Helicobacter pylori
Helicobacter pylori is a Gram-negative, microaerophilic bacterium that colonizes the stomach lining. It has evolved mechanisms to survive in the acidic environment of the stomach, such as producing urease to neutralize stomach acid. The infection leads to chronic inflammation (gastritis) and can disrupt the mucosal barrier, making it more susceptible to damage from gastric acid and pepsin.
NSAIDs and Peptic Ulcers
Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit the enzyme cyclooxygenase (COX), which is involved in the synthesis of prostaglandins. Prostaglandins play a crucial role in maintaining the integrity of the gastric mucosa by stimulating mucus and bicarbonate secretion, promoting mucosal blood flow, and facilitating epithelial cell repair. Inhibition of COX by NSAIDs reduces these protective mechanisms, increasing the risk of ulcer formation.
Clinical Manifestations
The symptoms of peptic ulcers can vary depending on the location and severity of the ulcer. Common symptoms include:
- Epigastric pain: A burning or gnawing sensation in the upper abdomen, often occurring between meals or at night.
- Bloating and abdominal fullness.
- Nausea and vomiting.
- Loss of appetite and weight loss.
- Hematemesis (vomiting blood) or melena (black, tarry stools) in cases of bleeding ulcers.
Diagnosis
The diagnosis of peptic ulcers involves a combination of clinical evaluation, laboratory tests, and imaging studies.
Endoscopy
Upper gastrointestinal endoscopy is the gold standard for diagnosing peptic ulcers. It allows direct visualization of the ulcer and enables biopsy for histological examination and testing for H. pylori infection.
Urea Breath Test
The urea breath test is a non-invasive diagnostic test for H. pylori infection. The patient ingests a urea solution labeled with a carbon isotope. If H. pylori is present, the bacterium's urease enzyme breaks down the urea, releasing labeled carbon dioxide, which can be detected in the patient's breath.
Stool Antigen Test
The stool antigen test detects H. pylori antigens in the feces. It is a non-invasive and reliable method for diagnosing H. pylori infection and monitoring the effectiveness of eradication therapy.
Treatment
The treatment of peptic ulcers aims to eradicate H. pylori infection, reduce gastric acid secretion, and promote mucosal healing.
Eradication of H. pylori
The standard treatment for H. pylori infection involves a combination of antibiotics (such as clarithromycin, amoxicillin, or metronidazole) and a proton pump inhibitor (PPI) to reduce gastric acid secretion. This regimen is typically administered for 10-14 days.
Acid Suppression Therapy
Proton pump inhibitors (PPIs) and H2-receptor antagonists are commonly used to reduce gastric acid secretion and promote ulcer healing. PPIs, such as omeprazole and esomeprazole, are more effective than H2-receptor antagonists in achieving acid suppression.
Cytoprotective Agents
Cytoprotective agents, such as sucralfate and misoprostol, can be used to protect the gastric mucosa and promote healing. Sucralfate forms a protective barrier over the ulcer site, while misoprostol, a prostaglandin analog, enhances mucosal defenses.
Complications
Peptic ulcers can lead to several complications if left untreated or inadequately managed.
Bleeding
Gastrointestinal bleeding is the most common complication of peptic ulcers. It can range from occult bleeding, leading to anemia, to massive hemorrhage, resulting in hematemesis or melena. Endoscopic hemostasis is often required to control active bleeding.
Perforation
Perforation occurs when the ulcer erodes through the full thickness of the gastric or duodenal wall, leading to the leakage of gastric contents into the peritoneal cavity. This results in peritonitis, a life-threatening condition that requires emergency surgical intervention.
Gastric Outlet Obstruction
Chronic inflammation and scarring from peptic ulcers can lead to gastric outlet obstruction, characterized by nausea, vomiting, and abdominal distension. Endoscopic dilation or surgical intervention may be necessary to relieve the obstruction.
Prevention
Preventive measures for peptic ulcers include:
- Avoiding the use of NSAIDs or using the lowest effective dose for the shortest duration possible.
- Using alternative pain relief medications, such as acetaminophen, when appropriate.
- Eradicating H. pylori infection in individuals with a history of peptic ulcers.
- Implementing lifestyle modifications, such as avoiding smoking, limiting alcohol consumption, and managing stress.
Epidemiology
Peptic ulcers are a common gastrointestinal disorder, affecting millions of people worldwide. The prevalence of H. pylori infection varies by region, with higher rates in developing countries. The widespread use of NSAIDs has also contributed to the incidence of peptic ulcers, particularly in older adults.
Research and Future Directions
Ongoing research in the field of peptic ulcers focuses on understanding the pathogenesis of H. pylori infection, developing new diagnostic methods, and exploring novel therapeutic approaches. Advances in molecular biology and genomics may lead to the identification of new targets for treatment and prevention.