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– THERAPEUTIC TARGETS & MANAGEMENT:
Primary pharmacological intervention aims to restore physiological homeostatic balance. This is achieved by either competitively blocking receptor sites, allosterically inhibiting enzymes, or supplementing missing metabolic products.
â– CRITICAL CARE MANAGEMENT PROTOCOL:
Continuous cardiopulmonary and metabolic monitoring is paramount during acute decompensation. Maintain strict control over fluid ratios and oxygenation parameters.
[HY-BOARD-1084]
🌟 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. Absolute contraindications include pregnancy, renal insufficiency, or concurrent use of metabolic inhibitors. Do not delay airway protection and resuscitation maneuvers for low-priority imaging.