Pyloric Stenosis Flashcards
Describe the pathophysiology of pyloric stenosis.
Progressive hypertrophy of pyloric sphincter muscle causing gastric outflow obstruction (narrowing of gastric antrum)
3 risk factors for pyloric stenosis?
Male sex (M:F = 4:1).
10-15% FHx
Caucasian
Summarise the epidemiology of pyloric stenosis
4/1000 live births.
Presents at 4-6 weeks
What are the presenting symptoms of pyloric stenosis?
Forceful/ projectile non-billous vomiting after every feed
Sometimes haematemesis 2to gastritis or Mallory-Weiss tear at the gastro-oesophageal junction.
Persistently hungry following projectile vomiting.
Constipation
What are 3 general signs of pyloric stenosis?
Weight loss
Signs of dehydration: Increased CRT, Decrease skin turgor, Sunken fontanelle, Decreased urinary output
Jaundice (5%).
Give 2 gastrointestinal signs of Pyloric stenosis
Visible peristalsis from left-to-right upper quadrant during a feed.
‘Olive-sized’ pyloric mass in RUQ palpated during feed/ immediately after a vomit
What test can be performed in suspected pyloric stenosis?
Test feed with NGT in situ + stomach aspirated
Whilst child is feeding, palpate for a pyloric mass + observe visible peristalsis
What picture is seen on blood gas in pyloric stenosis?
Hypochloraemic hypokalaemic metabolic alkalosis secondary to vomiting
Decreased K+ / Cl-/ Na+
Increased HCO3-/Urea
+ve base excess
+/- mild, unconjugated hyperbilirubinaemia.
What may the blood gas picture progress to in late pyloric stenosis as the dehydration worsens?
Paradoxical Lactic acidosis
High Na+, H+, K+, Cl-
What is the imaging modality of choice in pyloric stenosis? What can be seen?
USS abdomen
Hypertrophy of pyloric muscle, with wall thickness > 3mm, length > 15 mm + diameter >11mm
What is the preoperative management for pyloric stenosis?
Initial fluid bolus (10-20ml/kg) for acute hypovolaemia
Slow continuous IV fluid replacement at 1.5x maintenance rate with 5% dextrose + 0.45% saline
Correct K+ levels using KCl in IV maintenance fluids when urine output adequate
NBM + NGT insertion, aspirated 4 hourly
What is the surgical management for pyloric stenosis?
Ramstedt pyloromyotomy
Laprascopically or through supra-umbilical incision
Pylorus divided longitudinally down to the mucosa
What is the prognosis of pyloric stenosis?
Excellent post-surgery.
Initial postoperative vomiting common but settles within 24-48 hours.
