Peptic Ulcer disease - B. Pharma 2nd Semester Pathophysiology notes pdf
Peptic Ulcer disease
Contents
Peptic Ulcer disease
• Etiology
• Risk factor
• Pathogenesis
• Symptoms
• Treatment
Objectives
At the end of this lecture, student will be able to
• Define peptic ulcer disease
• Explain the etiology of peptic ulcer disease
• Describe the pathophysiology of peptic ulcer disease
Peptic Ulcer
• Breach in the mucosa of the alimentary tract, which extends through the muscularis mucosa into the submucosa or deeper
• Chronic and most often solitary, lesions
• Any portion of gastrointestinal tract exposed to the aggressive action of acid-peptic juices
• Erosion of GI mucosa resulting from digestive action of HCl and pepsin
Duodenal vs gastric ulcers
DUODENAL | GASTRIC | |
INCIDENCE | More common | Less common |
ANATOMY | First part of duodenum – anterior wall | Lesser curvature of stomach |
DURATION | Acute or chronic | Chronic |
MALIGNANCY | Rare | Benign or malignant |
Peptic ulcer
Imbalance between aggressive & protective factors
Aggressive factors
• Gastric acid
• Proteolytic enzyme
Protective factors
• Mucosal layer
• Bicarbonate secretion
• Prostaglandins
Risk factors of peptic ulcers
• Helicobacter pylori
• Non Steroidal Anti-inflammatory Drugs
• Steroid therapy
• Smoking and Excess alcohol intake
• Genetic factors
• Zollinger Ellison syndrome – rare syndrome caused by gastrin-secreting tumour
• Blood group O and Hyperparathyroidism
Pathophysiology of peptic ulcers
Gastric acid and pepsin
• Potential for producing mucosal damage is related to the secretion of gastric (hydrochloric) acid and pepsin
• Hydrochloric acid - parietal cells - receptors for histamine, gastrin, and acetylcholine
• Increased acid secretion - duodenal ulcers - HP infection
• Patients with ZES have gastric acid hypersecretion resulting from a gastrin-producing tumor
• Patients with gastric ulcer - normal or reduced rates of acid secretion
Mucosal defense mechanisms
• Protect the gastroduodenal mucosa from noxious endogenous and exogenous substances
• Bicarbonate barrier protect the stomach from the acidic contents
• Epithelial cell restitution, growth, and regeneration
• Maintenance of mucosal integrity and repair is mediated by the production of endogenous prostaglandins
H. pylori infection
Mechanisms include:
1) Direct mucosal damage
2) (b) Alterations in the host immune/inflammatory response
3) Hypergastrinemia leading to increased acid secretion
• Virulence factors (vacuolating cytotoxin, cytotoxin-associated gene protein, and growth inhibitory factor)
• Elaborating bacterial enzymes (lipases, proteases, and urease), and adherence
• Lipases and proteases degrade gastric mucus
• Ammonia produced by urease - toxic to epithelial cells
• Bacterial adherence enhances uptake of toxins into gastric epithelial cells
NSAID Induced
• Direct or topical irritation of the gastric epithelium and
• Systemic inhibition of endogenous mucosal prostaglandin synthesis
• Inhibit both COX-1 and COX-2 to varying degrees
• Neutrophil adherence may damage the vascular endothelium
• Lead to a reduction in mucosal blood flow
• Liberate oxygen-derived free radicals and proteases
Symptoms of peptic ulcers
• Abdominal pain that is often epigastric - burning - vague discomfort, abdominal fullness, or cramping
• A typical nocturnal pain that awakens the patient from sleep
• Severity of ulcer pain varies from patient to patient
• May be seasonal, occurring more frequently in the spring or fall
• Episodes of discomfort usually occur in clusters lasting up to a few weeks followed by a pain-free period or remission lasting from weeks to years
• Heartburn, belching, and bloating often accompany the pain
• Nausea, vomiting, and anorexia
Complications of peptic ulcers
• Obstruction – pyloric stenosis and duodenal stenosis
• Hemorrhage – blood in stools; if chronic – leads to anemia
• Perforation
• Malignant transformation to carcinoma
Summary
• Ulcers are defined as a breach in the mucosa of the alimentary tract, which extends through the muscularis mucosa into the submucosa or deeper
• Etiological factors are helicobacter pylori infection, nonsteroidal anti-inflammatory drugs, critical illness, hypersecretion of gastric acid , viral infections ,vascular insufficiency
• HP infection alters host inflammatory response and damages epithelial cells directly by cell-mediated immune system whereas NSAID cause direct irritation to epithelium and decrease PGE2
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