Pyloric Stenosis Passmed Flashcards
What is Pyloric Stenosis and when does it typically present?
Pyloric stenosis typically presents in infants between the second to fourth weeks of life with symptoms of vomiting, but can occasionally present as late as four months.
What causes Pyloric Stenosis?
Pyloric stenosis is caused by hypertrophy of the circular muscles of the pylorus.
What is the incidence of Pyloric Stenosis and which groups are more commonly affected?
Pyloric stenosis has an incidence of 4 per 1,000 live births, is 4 times more common in males, 10-15% of infants have a positive family history, and first-borns are more commonly affected.
What are the clinical features of Pyloric Stenosis?
Clinical features include ‘projectile’ vomiting typically 30 minutes after feeding, constipation, dehydration, a palpable mass in the upper abdomen, and hypochloraemic, hypokalaemic alkalosis due to persistent vomiting.
How is Pyloric Stenosis diagnosed?
Diagnosis of Pyloric stenosis is most commonly made by ultrasound.
What is the management strategy for Pyloric Stenosis?
Management of Pyloric stenosis involves Ramstedt pyloromyotomy.
summarise plyloric stenosis
Pyloric stenosis
Pyloric stenosis typically presents in the second to fourth weeks of life with vomiting, although rarely may present later at up to four months. It is caused by hypertrophy of the circular muscles of the pylorus.
Epidemiology
incidence of 4 per 1,000 live births
4 times more common in males
10-15% of infants have a positive family history
first-borns are more commonly affected
Features
‘projectile’ vomiting, typically 30 minutes after a feed
constipation and dehydration may also be present
a palpable mass may be present in the upper abdomen
hypochloraemic, hypokalaemic alkalosis due to persistent vomiting
Diagnosis is most commonly made by ultrasound.
Management is with Ramstedt pyloromyotomy.
Parents bring their 4 week old formula fed infant to the short stay paediatric ward. They are concerned because he has persistent non-bilious vomiting and is becoming increasingly lethargic. Despite this, his appetite is substantial. On examination, he appears pale and you can see visible peristalsis in the left upper quadrant. What is the most likely diagnosis?
Pyloric stenosis
Cows milk protein allergy
Duodenal atresia
Malrotation
Gastro oesophageal reflux disease
This presentation should raise the suspicion of pyloric stenosis. Visible peristalsis can be visualised as the stomach tries to push its contents past the obstruction. The vomiting is non-bilious as the level of obstruction is proximal to the second part of the duodenum where bile enters the gastrointestinal tract. This is contrast to malrotation and duodenal atresia.
A 2-week-old baby boy presents to the emergency department with persistent vomiting. The father states that the child’s vomiting is ‘like a fountain’. What one investigation is most appropriate to help you confirm your suspected diagnosis?
Abdominal X-ray
CT Abdomen
Tissue Transglutaminase (TTG) antibodies (IgA)
Upper GI contrast study
US Abdomen
US Abdomen
The key investigation in pyloric stenosis is ultrasound
The history above is classic of pyloric stenosis- forceful projectile vomiting; in this case described like a fountain.
Abdominal x-ray is of little use for pyloric stenosis.
CT scans are used much more rarely in children, especially so young due to high dose radiation.
TTG Antibodies would help you diagnose coeliac disease, which this child does not have as they will not have started eating any gluten containing products at 2 weeks.
Upper GI contrast study is rarely performed to diagnose pyloric stenosis, but on the occasions when it is used, it is generally for children outside the normal age bracket.
US Abdomen is the most commonly used diagnostic test.
A 2-month old baby is admitted to the Paediatric Ward with persistent vomiting and failure to gain weight.
Bloods taken on admission show the following:
Na+ 136 mmol/l
K+ 3.1 mmol/l
Cl- 81 mmol/l
HCO3- 30 mmol/l
An ultrasound of the stomach and duodenum is performed:
What is the most likely diagnosis?
Duodenal atresia
Pyloric stenosis
Malrotation
Gastro-oesophageal reflux disease
Coeliac disease
Pyloric stenosis
The ultrasound demonstrates a thickened and elongated pylorus. The bloods also show a hypochloraemic, hypokalaemic alkalosis in keeping with the diagnosis.
