FOUNDATION OVERVIEW: PEPTIC ULCER DISEASE
Peptic ulcers are lesions in the stomach or duodenum that extend deeper into the gastrointestinal (GI) tract than other acid-related disorders. These lesions develop in response to damage by gastric acid and pepsin. Gastric ulcers occur primarily on the lesser curvature but may occur anywhere in the stomach. In contrast, duodenal ulcers occur in the first part of the duodenum. Peptic ulcer disease (PUD) is divided into three forms: (1) Helicobacter pylori (H. pylori)-induced; (2) nonsteroidal anti-inflammatory drug (NSAID)-induced; and (3) stress-related mucosal damage (SRMD). A comparison of characteristics of peptic ulcer is summarized in Table 43-1.
TABLE 43-1Comparison of Common Forms of Peptic Ulcer ||Download (.pdf) TABLE 43-1 Comparison of Common Forms of Peptic Ulcer
|Characteristic ||H. pylori Induced ||NSAID Induced ||SRMD |
|Condition ||Chronic ||Chronic ||Acute |
|Site of damage ||Duodenum > stomach ||Stomach > duodenum ||Stomach > duodenum |
|Intragastric pH ||More dependent ||Less dependent ||Less dependent |
|Symptoms ||Usually epigastric pain ||Often asymptomatic ||Asymptomatic |
|Ulcer depth ||Superficial ||Deep ||Most superficial |
|GI bleeding ||Less severe, single vessel ||More severe, single vessel ||More severe, superficial mucosal capillaries |
H. pylori is a spiral-shaped, pH-sensitive, gram-negative, urease-producing bacteria that resides between the mucus layer and the gastric epithelium. The exact mechanism of gastric injury is unknown, but theories include: the production of enzymes/cytotoxins, increased gastric acid production, and alterations in the host immune response. H. pylori infection is recognized as a risk factor for gastric cancer.
Nonsteroidal Anti-inflammatory Drugs
Damage from NSAIDs occurs by two mechanisms: (1) direct irritation of the gastric epithelium; and (2) systemic inhibition of prostaglandin cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) synthesis. Up to 25% of chronic NSAID users will develop ulcer disease. NSAIDs are associated with gastric ulcers.
Stress-Related Mucosal Damage
Stress ulcers are superficial lesions in the mucosal layer of the stomach. The most common cause of GI bleeding in the intensive care unit is stress ulcers.
The clinical presentation of PUD includes nonlocalized epigastric pain, heartburn, belching, bloating, nausea, and anorexia. Duodenal ulcer pain may be worse with an empty stomach (at night or between meals). Gastric ulcer pain occurs at any time and may be worsened with eating. Both types of ulcers can occur in the absence of symptoms, especially gastric ulcers in the elderly. Patients can present with varied symptoms; therefore, no symptom can differentiate between H. pylori, NSAID, or SRMD ulcers.
GI bleeding, perforation, and obstruction can occur with H. pylori or NSAID-induced ulcer disease. Symptoms of bleeding include vomiting blood or black-colored stools. Perforation may begin as a sharp sudden pain, but then the pain spreads ...