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 may show hypokalemia, hypochloremia alkalosis
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

See Also

• Abdominal Pain (Peds)

Source

UpToDate

Tintinalli