Surgical abdominal conditions (malrotation, pyloric stenosis, intussusception, appendicitis) Flashcards
What is the most common cause of vomiting in children?
Infection! Not surgical abdomen
Which gender are more at risk of surgical abdominal conditions?
Boys
What anatomical defect is the biggest risk factor for developing malrotation with volvulus and why?
Narrow-based mesentery between ileocaecal junction and DJ flexure - allows gut to twist on superior mesenteric vessels
What does malrotation refer to? What is the difference between incomplete malrotation and complete non-rotation?
Malrotation refers to the embryological process of gut development, whereby the gut rotates on its axis to form the mature gut. In in complete malrotation there’s some rotation (but not enough), where as in complete non-rotation there’s no rotation at all.
Is the vomiting in malrotation with volvulus bile-stained or not? Why?
Bile-stained - occlusion is beyond Ampulla of Vater
Go through the pathophysiology of how malrotation can lead to volvulus
360 degree twisting of small intestine = occlusion of venous and lymphatic vessels = engorgement of vessels and duodenal obstruction leading to vomiting. 760 degree twist = occlusion of superior mesenteric arterial vessels = mid-gut ischaemia and necrosis.
What do children with malrotation with volvulus usually present with? At what age?
Often present as baby with feeding difficulties and bile-stained vomiting, usually in first month of life (90% by 1 year)
Name 3 signs of severe volvulus
PR bleeding
Abdominal distension
Abdo tenderness
What is the usual initial Ix for malrotation with volvulus? What is the expected sign?
AXR - look for dilatation of stomach and proximal duodenum, and collapsed distal small intenstine
What is the best Ix for malrotation with volvulus?
Upper GI contrast study, looking for blockage of contrast.
What is the main treatment for malrotation with volvulus?
Surgery - untwist bowel, widen mesentery and take appendix out (high chance of appendicitis in future)
Name 4 complications of treatment of malrotation with volvulus.
Recurrent volvulus
Intestinal obstruction
Intussusception
Death
What is the most common cause of intestinal obstruction in a child?
Pyloric stenosis
What is the usual presentation of pyloric stenosis?
Progressive projectile, non-bilious vomiting in an infant who always wants to feed after each vomit.
At what age does a child with pyloric stenosis usually present?
3-6 weeks
Name 5 Ddx for non-bilious vomiting
Pyloric stenosis Sepsis (UTI, meningitis) Reflux Overfeeding Metabolic diseases CAH
What is a risk factor for pyloric stenosis?
FHx
Go through the pathophysiology of pyloric stenosis. What metabolic derangement does it lead to?
Get progressive hypertrophy of the circumferential muscle of the pyloric sphincter = progressive obstruction. Leads to vomiting, which leads to dehydration and a hypochloraemia-hypokalaemic metabolic alkalosis (vomit out K+, Cl- and H+)
What is the most important aspect of management in pyloric stenosis?
Correcting the metabolic derangement - correct before surgery
What 2 signs on examination are specific for pyloric stenosis?
Palpable olive (you can feel the distended pylorus in RUQ on abdominal exam) and peristaltic waves visible
Name 2 Ix for a child with pyloric stenosis
Bloods - blood gas, UECs
U/S - look for hypertrophic pyloric sphincter and distended pylorus
What is the standard fluid resuscitation for a child with pyloric stenosis?
Start on 150ml/kg/day 0.45% NaCl with 5% dextrose +/- 20KCl/L if hypokalaemic
What is intussusception? When does an intussusception become symptomatic?
Invagination of proximal bowel into distal bowel. Only becomes symptomatic if small bowel invaginates into large bowel - bowel gets stuck in ileocaecal valve and can’t go back
What age is most common for intussuscpetion and why?
5-11 months - child is weaning off breastfeeding = loss of passive immunity = more infection. Theory is that the reactive lymphadenopathy (often in Peyer’s patches in ileum) is misrecognised by small bowel as poo = lots of pressure on small bowel = intussusception
Besides for lymphadenopathy, what are 2 other causes of intussusception?
Pathological lead points - Meckel’s diverticulum, polyp (Peutz-Jager syndrome), vascular malformation, duplication cyst - congenital malformation
Name 3 complications of symptomatic intussusception
Dehydration
Bowel obstruction
Bowel ischaemia and performation
Name 3 signs and symptoms of intussusception
Symptoms - colicky pain, bile-stained vomit, lethargy, redcurrant jelly stool
Signs - pallor, dehydration, palpable mass in RLQ (early sign before general distension)
Name 3 Ddx for intussusception
Normal colic
Gastroenteritis
Mesenteric adenitis
Other bowel obstructions (Meckel’s, inguinal hernia, appendicitis, duplication cyst)
What can you see on AXR for an intussusception?
Absence of gas in caecal region, discrete mass
What is the best Ix for intussusception? What are you looking for?
U/S - look for target sign
What is the difference between a simple and complicated intussusception? Go through management of each
Simple - less than 48 hrs, no peritonitis, stable. Mx - fluid, Abs, air enema reduction (push bowel back in to place)
Complex - more than 48 hrs, peritonitis or septic. Mx - laparotomy
What is the major complication of any management of intussusception? How quickly does this usually happen?
Recurrance, often in first 24 hrs
What are the differences in presentation between the typical appendicitis, retrocaecal appendicitis, pelvic appendicitis and perforated appendicitis?
Typical - periumbilical shifting to RIF pain. Vomiting, anorexia, guarding, rebound/percussion tenderness
Retrocaecal - vague RIF pain and tenderness, often without guarding
Pelvic - lower abdo pain and tenderness, urinary symptoms and small volume diarrhoea
Perforated - generalised peritonitis, poorly localised
What 2 Ix are indicated for appendicitis in a child?
AXR and U/S - no CT
What are the principles of management of appendicitis
Correct fluid and electrolytes, then transfer to theatre
When should you start thinking that a child diagnosed with gastroenteritis might actually have a surgical cause for their symptoms?
If 24 hrs of fluid replacement doesn’t improve their condition
