Pyloric stenosis

Background

• More common in males (5:1) & firstborn children (30%)
• Symptoms usually begin between 3-6 weeks of age, rarely after 12 weeks

Diagnosis

1. Immediate post-prandial, non-bilious, often projectile vomiting, but desires to feed ("hungry vomiter")
2. Palpable mass in in RUQ to epigastric region, occassionally may see peristaltic waves
3. Labs might show a low K, Low Cl, & hypo-Cl alkolosis
4. Imaging
   1. Abdominal xray: May show large stomach bubble
   2. U/S: ~ 95% Sn/Sp

Differential Diagnosis

1. Adrenal crisis
2. hyperkalemic acidosis
3. hypokalemic alkalosis

Treatment

1. IVF
   1. Normal electrolytes and no e/o dehydration
      1. 5% dextrose w/ 0.25% NaCl and 2 meq KCl per 100 mL
   2. Moderate or severe dehydration
      1. Higher NaCl concentrations (0.5% to normal saline) and higher rates of administration (1.5 to 2 times maintenance)
2. NGT
3. Surgery
   1. Can be delayed 24-36 hr to rehydrate infant

Precautions

• Ensure that kidneys are functional prior to giving potassium
• Do not give LR
• May lead to worsening alkalosis --> apnea in infants

Source

UpToDate