â– LECTURE OVERVIEW: Infantile Hypertrophic Pyloric Stenosis is a metabolic and mechanical obstruction disorder of the gastric outlet.
â– STENOSIS MECHANISMS:
1. Pyloric Hypertrophy: Hypertrophy and hyperplasia of the circular smooth muscle fibers of the pyloric sphincter.
2. Channel Compression: The pyloric canal is physically elongated and narrowed, completely obstructing gastric emptying.
3. Vomiting Phase: Swallowed milk accumulates in the stomach, leading to non-bilious projectile vomiting.
4. Hydrogen/Chloride Wasting: Agonizing gastric vomiting wastes hydrochloric acid (HCl) and sodium.
5. Compensatory Alkalosis: Loss of acid drives the kidneys to retain bicarbonate, resulting in hypokalemic hypochloremic metabolic alkalosis.
â– SPECIAL CLINICAL POPULATIONS & METABOLIC DEVIATIONS:
Infants display higher body water ratios and immature renal filtration capacity, whereas geriatric cohorts exhibit reduced physiologic reserves, progressive heart/renal decline, and polypharmacy interactions.
â– SECONDARY PREVENTION METRICS:
Implementing long-term dietary adaptations, physical therapy, and compliance aids reduces the rate of recurring acute crises by more than half.
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🌟 Dynamic Clinical Key:
Presents in first-born male infants between 2 and 6 weeks of age with non-bilious projectile vomiting after feeding. Examination reveals a palpable, firm 'olive-shaped' mass in the epigastrium. Surgical repair with a pyloromyotomy is curative. Adjust weight-based dosing for pediatric cohorts and use the 'start low and go slow' approach for seniors. Patient education regarding warning signs and therapy adherence is the cornerstone of secondary prevention.