Pyloric stenosis

Question 1

Epidemiology of pyloric stenosis

Answer 1

• hypertrophy of the pyloric muscle causing gastric outlet obstruction
• 2-4/ 1,000 births
• M:F 4:1
• more common in:
  
  • first borns
  • FHx (esp. on maternal side)

Question 2

Clinical features of pyloric stenosis

Answer 2

• vomiting
  
  • increasing in frequency and force
  • ultimately becomes projectile
• hunger after vomiting
• dehydration
  
  • leads to loss of interest in feeding
  • hypochloraemicmetabolic alkalosis (+ hyponatraemia, hypokalaemia)
• weight loss- in delayed presentation

Question 3

Diagnosis of pyloric stenosis

Answer 3

• Unless IV resusciatation needed…
• test feed
  
  • ​give milk feed
  • calms hungry infant
  • gastric peristaltic movement from left to right
• examination
  
  • ​pyloric mass ‘olive’ mass palapable in right upper quadrant
  • may need to empty stomach of air with NG tibe
• USS
  
  • ​when diagnosis doubful

Question 4

Treatment of pyloric stenosis

Answer 4

• correct any fluid and electrolyte distubance
  
  • 0.45% saline and 5% dextrose w/ potassium supplements
• pyloromyotomy
  
  • ​division of hypertrophied muscle down to but not including the mucosa
  • open procedure or periumbilical or laparoscopically
• post-op
  
  • ​fed within 6h
  • discharge 2 days

Question 5

Describe the fluid and electrolyte, why this occurs and fluid resuscitation

Answer 5

Hypocholoraemic alkalosis with hyponatraemia and hypokalaemia

Due to vomiting stomach contents,

This prolonged vomiting causes progressive loss of fluids rich in hydrochloric acid, which causes the kidneys to retain hydrogen ions in favor of potassium.

The dehydration may result in hypernatremia or hyponatremia and may result in prerenal renal failure.

Elevated unconjugated bilirubin levels may be present.