Vomiting (paeds) Flashcards
What is the definition of vomiting?
Physical act whereby gastric contents are forcefully brought up and out of the mouth by the sustained contraction of abdominal muscles and the diaphragm at a time where the cardia of the stomach is raised and pylorus is contracted
How is vomiting different to: regurgitation? Rumination? Possetting?
Regurgitation - effortless expulsion of gastric contents - healthy infants + older children who eat too much
Possetting - small volume vomits during or between feeds in an otherwise well infant
Rumination - frequent regurgitation of ingested food, functional or behavioural disorder
What are the ‘vomiting centre’ and the chemoreceptor trigger zone?
Vomiting centre = medulla
Chemoreceptor trigger zone (CTZ) = floor of the 4th ventricle
Receptors: muscarinic (M1), histaminergic (H1), dopaminergic (D2), serotonin (5-HT3), substance P (NK1)
Precipitants: toxic material in the GI lumen; visceral pathology; vestibular disturbance; CNS stimulation; blood or CSF toxins
What are the essential points in a vomiting history?
Age of presentation
Bilious vs non-bilious - former = pathology distal to the ampulla of Vater in the 2nd part of the duodenum
Bloody vs non-bloody - structural damage vs inflammation
Projectile vs non-projectile - true projectile is pyloric stenosis, not associated with retching/nausea/sweating/tachycardia
Other symptoms - nausea, pain, diarrhoea, constipation, distension; headache/visual changes/polyuria/polydipsia/weightloss (DKA or raised ICP)
Febrile vs afebrile
Hydration status
What are some redflags in a vomiting history/examination?
Meningism - neck stiffness, headache, photophobia; fever, rash etc.
Hypertension, bradycardia and irregular breathing (Cushing reflex secondary to raised ICP)
Costovertebral angle tenderness (pyelonephritis)
What are some key causes of vomiting secondary to obstruction in infants and children? How are they differentiated?
Pyloric stenosis - 1/300, 2-6wks old, projectile non-bilious vomiting, weight loss/failure to thrive; USS + hypokalaemic + hypochloraemic metabolic alkalosis (+high bicarbonate) + ‘olive shaped mass’ palpated when feeding
Malrotation with intermittent volvulus - most common in neonates but at any age if 1st bilious vomit in a ‘virgin abdomen’, pain, possible distension; upper GI contrast
Intussusception - 6m-2yrs, M>F, colicky abdominal pain - drawing legs up, redcurrant jelly stool, possible palpable sausage-shaped abdominal mass, bilious vomiting, dehydrated; USS - target sign; air enema
Hirschsprung disease - 1/5000, mostly rectosigmoid denervation, failure to pass meconium in 24hrs, difficult bowel movements, poor feeding, distension; plain or contrast AXR - dilated loops of bowel + air-fluid levels)
Strangulated hernia/adhesional obstruction - bilious vomits, pain
Foregin body - Hx
What are some non-obstructive GI causes of vomiting in infants and children?
Necrotising enterocolitis (NEC) - usually preterm, distension, bilious vomiting; Abx, rest, poss surgical referral
GORD - vomiting associated with feeds
Gastroenteritis
Peptic ulcers
Food allergy - vomiting, loose stools or constipation; possible eczema; food diary + elimination
IBD
Appendicitis - central abdo pain +/- migration, loss of appetite, vomiting, pyrexia; Murphy’s sign
Pancreatitis - vomiting, abdo + back pain; Cullen’s/Grey-Turner’s
Achalasia
What are some non-GI causes of vomiting in infants and children?
Neurological - raised ICP (various causes; early morning vomits), migraine
Infectious - sepsis, meningitis, UTI, otitis media
Metabolic - DKA (polyuria/dipsia, hyperglycemia, ketonuria, metabolic acidosis) congenital adrenal hyperplasia
Renal - obstructive uropathy
Toxic - lead, iron, vit A + D; digoxin, theophylline etc.
Cardiac - congestive heart failure
Psych - eating disorders, child abuse/neglect
Functional - cyclical vomiting syndrome
What are the common causes of paediatric vomiting by age group?
0-2days = duodenal or other intestinal atresia, tracheo-oesophageal fistula (TOF), meconium ileus
3d-1m = milk protein intolerance, necrotising enterocolitis, gastroenteritis, pyloric stenosis, malrotation/volvulus
1m-36m = gastroenteritis, UTI, GORD, intussusception, milk protein intolerance
36m-12yrs = gastroenteritis, UTI, DKA, raised ICP, appendicitis
12-18yrs = gastroenteritis, appendicitis, DKA, raised ICP, bulimia, pregnancy
What are some investigations for vomiting?
Obviously guided by presentation
Bloods: FBC, U+E, CRP/ESR, LTF; H.pylori serology; amylase, lipase, glucose
Samples: stool virology, urinalysis
Scans: abdo USS, AXR +/- contrast, endoscopy, CT/MRI head
Exclude systemic disease; poss surgical opinions
What are some consequences of vomiting?
DEHYDRATION AND HYPOGLYCAEMIA
Hypochloraemic alkalosis (due to loss of HCl in stomach acid), hypokalaemia, hyponatraemia
Mechanical injuries - Mallory-Weiss tear or Boerhaave’s syndrome (a fullmural thickness tear)
Dental injuries - erosions and caries
Stricture, Barrett’s oesophagus, aspiration, anaemias, failure to thrive
What are some anti-emetics used in children?
Prochlorperazine, metoclopramide (D2 antagonists), cyclizine (H1 antagonist),
What surgery do you use to treat pyloric stenosis?
Pyloromyotemy or Ramstedt procedure
What is the advisable milk intake for a new born?
Newborn-2m:
Up to 90ml/feed at 6-8 feeds/day
2m+:
Up to 150ml/feed every 2-3hrs
What do you do if a newborn is posseting excessively?
Give alginates – Gaviscon – 1-2wk trial – if symptoms improve – continue; advise stopping every two weeks to see if it has resolved (90% will resolve within the first year)
Maintain breast feeding and top up with expressed breast milk (or formula feeds) as appropriate if serial weights not showing improvements on current regimen
If continues for 1-2wks despite Gaviscon – consider 4wk trial of PPI (omeprazole suspension) or histamine receptor antagonist (H2RA, e.g. ranitidine)
