Vomiting and malabsorption in children Flashcards
What are the physiological phases of vomiting?
Pre-ejection phase (nausea, tachycardia, pallor)
Retching (deep breaths taken against a closed glottis and reverse peristaltic movements)
Vomiting
Post-ejection phase (lethargic, pallor, sweat)
Where is the vomiting centre of the brain located?
In the Medulla
The chaemoreceptor trigger zone that is triggered by certain chemicals and toxins is located at the base of the 4th ventricle
What are the triggers of vomiting?
Enteric pathogens Infections Visual / olfactory stimuli (& fear) Head injury / raised ICP Inner ear stimuli Metabolic derangements / chaemotherapy
What are the different types of vomiting?
Vomiting with retching
Projectile vomiting
Bilious vomiting
Effortless vomiting
Haemetemesis (usually peptic ulcers / portal hypertension)
What are the most common causes of vomiting in infants?
gastro-oesophageal reflux
cow’s milk allergy
Infection
Intestinal obstruction
Pyloric stenosis
What are the most common causes of vomiting in children?
Gastroenteritis Infection Appendicitis Intestinal obstruction Raised ICP Coeliac disease
What are the most common causes of vomiting in young adults?
Gastroenteritis Infection H. Pylori infection Appendicitis Raised ICP DKA Cyclical vomiting syndrome Bulimia
What are the recommended values for feeding volume for neonates ans infants?
Neonates: 150 mL/kg/day
Infants: 100 mL/kg/day
In neonates and infants that have been vomiting constantly what investigation needs to be done? What is commonly seen on investigation? Initial management?
Blood gas test
Often see hypokalaemic hypochloric metabolic alkalosis (been vomiting all HCl)
Fluid resuscitation is first treatment, then treat underlying cause of vomiting
When does pyloric stenosis tend to occur? How does it present?
Babies 4-12 weeks (more common in boys)
Presents with projectile non-bilious vomiting and associated weight loss, dehydration and +/- shock
What is the characteristic electrolyte disturbance seen in pyloric stenosis?
Metabolic alkalosis (Increased pH)
Hypochloraemia
Hypokalaemia
What is effortless vomiting? How is it treated?
Vomiting that is almost exclusively due to gastro-oesophageal reflux
Tends to reslove spontaneously
(omeprazole or something for symptomatic treatment)
What are some factors that predispose babies to gastro-oesophageal reflux?
They have a relaxed LOS
Often placed in lying down position
Most of their feeds are liquid
What are some of the symptoms that may accompany gastro-oesophageal reflux in children?
Vomiting
Haematemesis
Feeding problems
Failure to thrive
Apnoea / cough / wheeze / chest infections
Sandifer’s syndrome (spasmodic torsional dystonia)
Describe the common natural history of reflux in infants?
Starts at about 2 weeks of age
Worse around 4-6 months of age
Usually resolves after a year of age
What radiological investigations may be done on a child experiencing reflux?
Barium swallow
Oesophageal ultrasound
Oesophageal pH meter (does pH drop below 4)
Upper GI endoscopy (in serious cases)
How is gastro-oesophageal reflux treated in children?
Usually just:
Feeding advice + nutritional support
In serious cases:
Drugs +/- surgery
What feeding advice may be given to a parent with a child experiencing GOR?
Thickeners for liquids (keeps food in stomach)
Advice on appropriate food
Feeding positions
Check feed volumes
What are some examples of nutritional support that may be given to a child with GOR?
Calorie supplements
Exclusion diet (eg. cows milk)
Nasogastric tube
Gastrostomy
What are some drugs that may be given for GOR in children?
H2 receptor blockers
PPI’s
What surgery may be done in children with severe, persistent GER? Who is more likely to get this? Side effects?
Nissen fundoplication (Wrap the fundus around the LOS)
Done often in kids with cerebral palsy
May suffer from bloat, dumping and retching after surgery
What causes bilious vomiting? What does it look like?
Intestinal obstruction usually
Looks green or bright yellow in colour
What investigations may be done in a child with bilious vomiting?
Abdominal Xray
Contrast meal
What is chronic diarrhoea?
4 or more stools per day for 4+ weeks
What are some of the causes of diarrhoea?
- Motility disturbances (toddler diarrhoea / IBS)
- Active secretion of water (secretory)
(infective diarrhoea, inflammatory bowel disease) - Malabsorption of nutrients (osmotic)
(Food allergy, coeliac disease, cystic fibrosis)
What occurs in osmotic (malabsorption) diarrhoea?
Movement of water into the bowel to equilibrate the osmotic gradient - food not getting absorbed so needs more water to remain equally tonic
Usually due to malabsorption caused by:
- Enzymatic defect
- Transport defect
(this is the mechanism many laxatives work by)
What occurs in secretory (active) diarrhoea?
There is excessive secretion of water due to the active secretion of Cl by CFTR
This is usually precipitated by infection
How does stool volume compare between secretory and osmotic diarrhoea? Which one responds to fasting
Secretory diarrhoea has a larger stool volume
Osmotic diarrhoea responds to fasting, secretory does not
What are some causes of fat malabsorption?
Pancreatic disease - diarrhoea due to lack of lipase and resultant steatorrhoea (CF)
Hepatobiliary Disease - chronic liver disease, cholestasis
What is the most common cause of malabsorption in children?
Coeliac disease
a gluten sensitive enteropathy - affects about 1% population
What are the classic signs of coeliac disease?
- Abdominal distension (pot belly)
- Diarrhoea
- Failure to thrive
- Short stature
- Constipation
- Tiredness
- Dermatitis herpatiformis
What serological tests should be done when coeliac disease is suspected in a child?
Anti-tissue transglutaminase
Anti-endomysial
Check serum IgA because deficiency in 2% may result in false negatives
What non-serological screening for coeliac disease may be done?
Duodenal biopsy (gold standard)
Genetic testing
In coeliac disease what do you see on endoscopy?
Absence of villi
Erythematous mucosa (looks red / pink)
Scalloping (deepening) of the mucosal folds
What is needed for diagnosis of coeliac disease without biopsy?
ALL OF:
Patient must be symptomatic
Anti TTG > 10 times normal
Positive anti endomysial antibodies
HLA DQ2 / DQ8 positive (genes)
What treatment is given to children with coeliac disease?
Sent to a dietician:
- Gluten free diet for life
(don’t remove gluten before diagnosis because serological signs will resolve)
What do undigested vegetables in a childs stool suggest?
Chronic, non-specific “toddlers diarrhoea”
Tends to improve by itself with age
