Paediatric Surgery and GI Flashcards
What is Hirschprung’s disease?
Congenital abnormality causing the ganglionic cells in myenteric and submucosal plexuses to be missing
What is the pathophysiology of Hirschprung’s disease?
Leads to a narrow and contracted segment
The normally innervated bowel that is proximal to the affected area becomes dilated
How does Hirschprung’s disease normally present?
Usually within the neonatal period
Don’t pass meconium within first 48 hours
Signs of bowel obstruction
Abdominal distension
Bilious vomiting
How does Hirschprung’s disease present on examination?
On PR there is significant passage of wind and liquid stool when finger is removed. This can also lead to a delay in diagnosis as bowel is temporarily dilated.
How does Hirschprung’s disease present if the initial diagnosis has been missed?
Profound, chronic constipation + distension + no soiling
? Growth failure
What is the investigation for Hirschprung’s disease?
Full thickness rectal biopsy is diagnostic
What is the management of Hirschprung’s disease?
Rectal washout
Anorectal pull through (cut out affected bit and form an anastomosis
What are the complications of Hirschprung’s disease?
Hirschprung’s enterocolitis within first few weeks of life
What is Intussusception?
The proximal bowel folds into a distal segment of bowel to form a pouch
What is the pathophysiology of Intussusception?
The ileum usually passes into the caecum through the ileocaecal valve
Disruption of peristalsis = colicky pain
Disruption of venous and lymphatic drainage = ischaemia
Which other two abnormalities may be present in Intussusception?
Meckel’s Diverticulum or polyp likely to be present
What is the presentation of Intussusception? (4)
Episodic crying that is inconsolable/ colicky pain. Becomes pale/pallor around mouth and draws up legs when pain is present with periods of recovery in between
Redcurrant jelly stools are characteristic (bloody mucus in poo) but usually appear later on
Sausy shaped mass in the tummy
Signs of bowel obstruction (Bilious vomiting and Abdominal distension)
Which bedside tests should be performed to diagnose intussusception?
Baseline obs - looking for signs of shock/deterioration
Which blood tests should be performed to diagnose intussusception?
Surgical pre-op bloods
What imaging should be done to diagnose intussusception?
Probably not a CT
Abdominal X-ray - showing distended small bowel + absence of gas in large bowel
Abdominal USS helpful - shows doughnut sign
What is the management of Intussusception?
A → E
No signs of peritonitis
Drip and suck - insert NG tube
Rectal air insufflation
Signs of peritonitis
Laparotomy for peritonitis, perforation, prolonged (>24 hrs) or pathological lead point
What are the complications of Intussusception? (4)
Bowel perforation
hypovolaemic shock
gut necrosis
sepsis
What is pyloric stenosis?
Hypertrophy of the pyloric muscle leading to a gastric outlet obstruction
When does pyloric stenosis usually present?
2-8 weeks old (even if premature)
More common in:
Boys
Firstborns
Family history (maternal)
What are the symptoms of pyloric stenosis?
Vomiting
Non-bilious (too high up for that)
↑ in frequency and force over time until it becomes projectile
Happens within minutes of feeding
No diarrhoea
Hunger - baby is alert and ?dehydrated
Weight loss (delay in presentation)
What are the signs of pyloric stenosis?
↓ urine output
Metabolic disturbances
Hypochloraemic metabolic alkalosis
Hyponatraemia
Hypokalaemia
What are the bedside tests to diagnose pyloric stenosis?
Examination
Palpable, olive sized pyloric mass in RUQ
Fluid challenge/give a feed - May see visible left to right peristalsis in LUQ whilst feeding
What are the blood tests to diagnose pyloric stenosis?
U&E - electrolyte imbalances
? Pre-ops
VBG - check acid-base balance
What imaging should be done to diagnose pyloric stenosis?
Abdominal USS
What is the conservative/medical management of pyloric stenosis?
Insert NG tube if stomach needs decompressing
Correct electrolyte imbalances
What is the surgical management of pyloric stenosis?
Pyloromyotomy
Can usually feed within 6 hours of surgery, and discharged within 2 days
What are the causes of vomiting in an infant?
Bilious = malrotation, meconium ileus, necrotising enterocolitis, duodenal atresia
Non-bilious
Acute = Pyloric stenosis
Chronic = GORD, CMPA, allergies/intolerance
What is GORD in an infant?
The involuntary passage of gastric contents into the oesophagus due to inappropriate relaxation of the lower oesophageal sphincter. It is worsened by fluid diet, horizontal posture and short oesophagus
How would GORD present in an infant?
Recurrent vomiting Distress after feeding Failure to thrive Apnoea Aspiration
What are the risk factors for GORD in a baby?
NM = first born, boy, preterm, neurodevelopment disorder
M = post surgical e.g. diaphragmatic hernia repair
How would GORD in a baby be managed?
C = reassurance. should resolve after 1 year. Avoid overfeeding - keep feeds to small and often. ? adding thickener to foods
M = PPI/gaviscon/H2 antagonist
S = only if really bad
What are the complications of GORD in a baby?
Oesophagitis - haematemesis and Fe deficiency anaemia
Aspiration pneumonia
Hyperchloraemic metabolic alkalosis
Define colic
When a baby cries for a long time but there is not an obvious cause
Follows a rule of 3:
Lasts for >3 hours a day
Lasts for >3 days a week
Lasts for >3 weeks
What are the risk factors for colic?
NM - preterm/SGA, CMPA
M - mother smoked during pregnancy
What are the causes of colic? (7)
IT CRIES
Infection
Trauma
Cardiac (SVT) Reaction/Reflux Intussusception Eyes (corneal abrasion) Surgical (testicles)
What are the symptoms of colic?
High-pitched, inconsolable crying, usually during afternoon/evening
Burping
Pumping
Drawing up knees
Become red in the face
Define gastroenteritis
Sudden change to bowel movement leading to loose, watery stools, often with associated vomiting
What are the most likely causative agents for gastroenteritis?
Viral - rotavirus etc
Bacterial - campylobacter jejuni (+ severe abdo pain and bloody stools), shigella, E. coli (lots of diarrhoea, really dehydrated)
What is the management of cow’s milk protein allergy?
Conservative!
Reassure - self limiting - usually stops within 4 months
Feeding advice - Try without cow’s milk or mam can try hypoallergenic diet if she is breast feeding
What is Coeliac disease?
A bowel disease that occurs due to the presence of Gliadin, which is a factor of gluten, barley, rye etc. Gliadin causes an immunological response within the proximal small bowel leading to inflammatory damage
What is the pathophysiology behind coeliac disease?
- Gliadin is not broken down in the small intenstine so IgA binds to it
- Gliadin-IgA complex then binds to Transferrin receptors on enterocytes (coeliacs have more expressed)
- Complex is then phagocytksed and presented by MHC2 cells
- CD4 response = cytokine release and inflammatory damage
- Also recruits B cells = more IgA produced = more damage
How may coeliac disease CLASSICALLY present in a child?
Classic presentation = profound failure to thrive within 18-24 months after introducing gluten into the diet
Anaemia, osteomalacia, wasting of buttocks, bloating
Change in stools - steatorrhoea, diarrhoea
How does coeliac disease COMMONLY present in a child?
Variable presentation - usually more asymptomatic and older
Anaemia
Incidental finding when investigating other HLA-DQ2/8 conditions e.g. T1DM, autoimmune thyroiditis, dermatitis herpetiformis
Which blood tests should be done to investigate a child presenting with coeliac?
tTGA (tissue transglutaminase), IGA
Endomysal antibody
FBC if anaemic
What is the gold standard imaging to diagnose coeliac?
Endoscopic Duodenal biopsy
Have to eat normally for at least two weeks beforehand so can see the pathological changes
What are the findings on duodenal biopsy that signify coeliac disease?
Villous atrophy
Crypt abscesses
Intra-epithelial lymphocytic infiltration
What is the treatment of coeliac disease?
Remove gluten from the diet under dietician supervision
What are the complications of coeliac disease?
Osteoporosis, anaemia
malabsorption failure to thrive
Increased risk of small bowel cancer
What is the definition of failure to thrive?
Suboptimal weight gain in infants/children
A sustained drop in 2 centile spaces leading to growth stunting and delayed development if severe
What are the two main causes of malabsorption?
Reduced food intake - environmental, pathological, retention
Malabsorption - coeliac, IBD, CF, CMPA
What are the causes behind reduced food intake leading to malabsorption?
Environmental e.g. neglect, maternal depression
Pathological - impaired suck e.g. cleft palate, Cerebral palsy
Retention/Vomiting e.g. GORD
What questions could you ask to the parents of a child presenting with failure to thrive?
Feeding - breast or bottle? when were they weaned?
Development
Otherwise well?
Birth hx
Ask to keep a food diary for 3 days + behaviours
Which bedside and blood tests could be done to investigate a child presenting with failure to thrive?
Bed - urine MSC (rule out UTI or renal disease), pancreatic elastase if pancreatic insufficiency
Blood - IgA + tTGA (coeliac), FBC (cancer), U&E (renal disease and metabolic disorders)
How would a moderately dehydrated child present?
Head to toe
Sunken fontanelles/eyes Altered consciousness Dry mucous membranes Reduced skin turgor Reduced urine output/fewer wet nappies
Baseline obs and skin colour still normal
How would a severely dehydrated/shocked child present?
As with moderately + mottled/pale skin + cool extremities + deranged baseline obs e.g. tachycardia, hypotension, tachypnoea, prolonged cap refill
What is the fluid requirement for resuscitation fluids in a child?
20mls/kg
What is the fluid requirement for maintenance fluids in a child?
1st 10 kg = 100mls/kg/day
2nd 10 kg = 50mls/kg/day
The rest = 20mls/kg/day
Remember to divide total amount by 24 to get requirement per hour
What are the 4 broad categories for the causes of constipation in children?
Neonatal
Metabolic
Autoimmune
Functional
What are the neonatal causes of constipation?
Medical = meconium ileus secondary to cystic fibrosis
Surgical = intussusception, hirschprung’s, anal atresia/imperforate anus, lower spinal cord problem e.g. spina bifida
What are the metabolic causes of constipation?
Hypothyroidism
Hypocalcaemia
What are the autoimmune causes of constipation?
Coeliac
What are the functional causes of constipation?
Poor toilet training
Poor fluid intake
Low exercise
Hard poo = painful so scared to do it again and cycles round
What is the conservative management of constipation in children?
Use to gastrocolic reflex - sit them on the toilet after eating
Increase fluid and fibre and encourage exercise(unlikely to make a difference)
Refer to nurse led constipation clinic
Star chart!
What is the medical management of constipation in children?
First line = osmotic laxative so Lactulose or Movicol (Draws water into bowel so softens stool)
Second line = stimulant laxative e.g. Senna (irritates bowel wall so moves things along)
Both are contraindicated in IBD and bowel obstruction. Osmotics are also contraindicated in bowel perforation and toxic megacolon and may cause hyper/hypokalaemia
How is the pre-existing deficit in dehydration calculated? When would you add potassium?
ml = % dehydration X weight (Kg) X 10
So 7.5% X 10kg X 10 = 750ml as the pre-existing deficit
Replace the deficit over 48hours if over 5% dehydrated
Add potassium (20mmol in a 500ml bag) once they have passed urine UNLESS IN DKA
What are the signs of 5% (mild), 10% (mod) and >10% (severe) dehydration?
5%/mild = dry mucous membranes, reduced urine output
10%/moderate = very dry MM, oliguric, tachycardic
> 10%/severe = shock signs, anuric, reduced consciousness
When would 0.45% saline and 0.9% saline be used as fluid replacement in severe dehydration? Why do you need to correct the deficits slowly?
- 45% = if dehydration is isotonic or hyponatraemic e.g. excess fluid loss through vomiting/diarrhoea/DKA
- 9% = if dehydration = hypernatraemic
Correct slowly due to risk of cerebral oedema
What is sickle cell anaemia?
An autosomal recessive condition that results for synthesis of an abnormal haemoglobin chain termed HbS.
Symptoms in homozygotes don’t tend to develop until 4-6 months when the abnormal HbSS molecules take over from fetal haemoglobin.
What is the pathophysiology of sick cell anaemia?
polar amino acid glutamate is substituted by non-polar valine in each of the two beta chains (codon 6).
This decreases the water solubility of deoxy-Hb
in the deoxygenated state the HbS molecules polymerise and cause RBCs to sickle at a higher kPa
sickle cells are fragile and haemolyse; they block small blood vessels and cause infarction
How would a meckels diverticulum normally present?
Abdominal pain
Fresh blood in stool
Nausea and vomiting
Typically male and under 2
What is the pathophysiology of a meckels diverticulum?
Incomplete obliteration of the vitelline duct leads to an outpouching
This can then tort and become inflamed/BO
