Paediatric Gastro Flashcards
(135 cards)
What is pyloric stenosis
Hypertrophy of the pyloric muscle causing gastric outlet obstruction
When does pyloric stenosis present?
At 2-8 weeks.
More common in boys, particularly the first born
How does pyloric stenosis present?
Projectile non-bilious vomiting - typically 30 mins after feed, becomes increasingly projectile over time
Constipation
Dehydration- tachycardia, decreased wet nappies, dry mucous membranes, flat or depressed fontanelles
Palpable upper abdominal mass- olive sign
Hunger after vomiting (until severe dehydration sets in)
What blood gas abnormality occurs in pyloric stenosis and why?
Hypochloraemic, hypokalaemic metabolic alkalosis
-Occurs as prolonged vomiting leads to hypovolaemia
-This causes increase in aldosterone and renal absorption of sodium and water
-This causes subsequent loss of hydrogen ions
-This increases bicarbonate
-Chloride is loss in vomit
-Potassium is used in H+ K+ pump in kidney (kidney tries to keep as much H+ as it can)
How is pyloric stenosis diagnosed?
Gold- abdominal USS ( muscle thickness >4mm and muscle length >14mm)
May also do a test feed and capillary blood glucose (hypochloraemic hypokalaemic metabolic alkalosis)
How is pyloric stenosis treated?
Correct fluid and electrolyte abnormalities - IV fluids (1.5 maintenance with 10% dextrose and 0.9% saline)
Ramstedt pyloromyotomy - division of the hypertrophied muscle
What is Hirschsprung’s disease?
The absence of ganglion cells from the myenteric and submucosal plexus of part of the large bowel which leads to a narrow contracted segment
How common is Hirschsprung’s disease?
Occurs in 1 in 5000 births
More common in males
Increased in Down’s syndrome
Pathophysiology of Hirschsprung’s disease?
There is an absence of parasympathetic ganglion cells in the myenteric plexus.
These cells start higher up in the GI tract in development and move down towards the colon and rectum
In Hirschsprung’s the migration doesn’t happen so the distal end of colon has no ganglion cells
The aganglionic section of bowel does not relax causing it to become constricted (causing faecal obstruction)
The more proximal area becomes dilated.
Presentation of Hirschsprung’s disease?
Failure to pass Meconium in the first 24 hours
Chronic constipation since birth
Abdominal distention
Bile stained vomiting
Hirschsprung- associated enterocolitis
Diagnosis of Hirschsprung’s disease
Abdominal x ray
Contrast enema
Gold- rectal biopsy (shows absence of ganglion cells and large acetylcholinesterase- positive nerve trunks
Management of Hirschsprung’s disease
Initial - rectal washouts and bowel irrigation
Gold- surgery to remove the effected part of bowel (usually in first week of life)
What is intussusception
Invagination of one part of the bowel into the lumen of the adjacent bowel
Where does intussusception usually occur?
The ileo-caecal region
Epidemiology of intussusception
Infants aged 6-18 months
More common in boys
Presentation of intussusception
Severe colicky abdominal pain - infant will bring knees up and turn pale
Isolable crying
Vomiting
Red-current jelly stool
Sausage shaped mass in right upper quadrant
How is intussusception diagnosed?
USS- shows donut sign
How is intussception managed
Most can be treated with an air enema
10% need surgery
Illnesses associated with intussusception
Concurrent viral illness, henoch- schonlein purpura, cystic fibrosis, intestinal polyps, Meckel diverticulum
Complications of intussusception
Obstruction, gangrenous bowl, perforation, death
What is meckel’s diverticulum?
A congenital diverticulum in the small intestine which is a remanent of the vitelline duct which has failed to obliterate.
Explain the rule of 2’s for MEckel’s diverticulum
It occurs in 2% of the population, it is 2 feet from the ileocaecal valve, it is 2 inches long
How does Meckel’s diverticulum present
Can be asymptomatic
Can have pain which mimics appendicitis
Rectal bleeding
Intestinal obstruction - either due to omphalomesenteric band, volvulus or intussusception
How is Meckel;s diverticulum diagnosed
If child is stable- Meckel’s scan (99m technetium pertechnetate scan )
If acute then CT imaging or intra-operative diagnostic laparoscopy may be used.
Can also do a mesenteric angiography