Vomiting & Malabsorption, & Infant feeding/nutrition Flashcards
What is the physiology of vomiting?
Pre-ejection phase=pallor, nausea, tachycardia
Ejection phase=retch, vomit
Post-ejection phase-lethargic, pale and sweaty
Occurs as a result of stimulating vomiting centre located in the medulla oblongata
Where is the chemoreceptor trigger zone located?
Base of the 4th ventricle-stimulated by certain chemicals and toxins like chemotherapy
What are the types of vomiting?
Vomiting with retching (early morning is associated with intracranial pathology)
Projectile vomiting
Bilious vomiting
Effortless vomiting (regurg)
Haematemesis (peptic ulcer, portal HT)
If there is palpation of ‘olive’ (thickened pylorus) tumour and visible gastric peristalsis and they have projectile non bilious vomiting after the feed what do you do?
Blood gas-Hypokalemic, hypochloremic, metabolic alkalosis
USS-thickened pylorus=pyloric stenosis
- Fluid resuscitation
- Refer to surgeons-Ramstedt’s pyloromyotomy
Who does pyloric stenosis affect and what are the signs of it?
Babies 4-12 weeks
Boys>girls (classically 1st born boys)
Projectile non bilious vomiting
Weight loss
Dehydration +/- shock
What is the characteristic electrolyte disturbance of pyloric stenosis?
Metabolic alkalosis (increased pH)
Hypochloraemia
Hypokalaemia
Effortless vomiting/regurgitation is almost always due to what?
GORD
- Very common problem in infants
Effortless vomiting/regurg is self limiting & resolves spontaneously in the vast majority of cases. What are a few exceptions?
- CP
- Progressive neurological problems
- Oesophageal atresia +/- TOF operated
- Generalised GI motility problem
What is Sandifer syndrome?
Dystonic posturing due to reflux
How do you diagnose GORD?
H&E often sufficient
- Oesophageal PH study/impedance monitoring
- Endoscopy
- Radiological investigations (video fluoroscopy, Barium swallow)
When do we investigate GORD?
If GORD doesn’t get better after a year of age - investigate for causes of reflux & look at severity and evidence of oesophagitis and also rule out anatomical problems like hiatus hernia
In whom is video fluoroscopy done in?
Children with aspiration pneumonias to see if there is a pharyngeal pouch or any incoordination of swallowing mechanism
Growth altering is rare but if it is seen what does it require?
Further investigation
How is a pH catheter placed in pH studies?
pH catheter with a single sensor is placed 5cm above the GOJ/LOS-measures the number of the times the pH in the oesophagus drops below 4
Why is pH combined with pH impedance monitoring?
pH studies will only detect acid reflux (& not weak acid reflux or non acid reflux)
6 sensors-detects acid and non acid and also air reflux
When is upper GI endoscopy done in children?
Done under GA
- Persistent symptoms
- Growth faltering
- Non-response to anti-reflux therapy
What is the treatment for GOR?
- Feeding advice
(appropriateness of food, behavioural programme, feeding position) - Nutritional support
(calorie supplements, exclusion diet (cow’s milk protein free trial for 4 wks), NG tube, gastrostomy) - Medical Tx
- Surgery
What are the appropriate feed volumes for neonates and infants?
Neonates= 150ml/kg per day
Infants= 100ml/kg per day
What is the medica Tx for GOR?
- Feed thickener (Gaviscon, thick & easy)
- Acid supressing drugs = H2 receptor blockers, PPIs
(Prokinetic drugs like domperidone not usually recommended due to the cardiac side effects)
What are the indications for surgery?
Failure of medical treatment
Persistent:
- Failure to thrive
- Aspiration
- Oesophagitis
Vomiting without complications may not be an indication
What is the surgical procedure done for GOR?
Nissen fundoplication
(Children with CP are more likely to have complications of bloat, dumping & retching after surgery)
Successful surgery may unmask more generalised GI motility problems in the child
Why should Bilious vomiting ALWAYS ring alarm bells?
Due to intestinal obstruction until proved otherwise
What are the causes of bilious vomiting?
Intestinal atresia (newborn babies only)
Malrotation +/- volvulus
Intussusception
Ileus
Crohn’s disease with strictures
What investigations are recommended for bilious vomiting?
Abdominal xray
Consider contrast meal
Surgical opinion re exploratory laparotomy
How is the SA of the small intestine so suited for absorption and what can be the issue if this is altered?
Mucosal folds and villi-600 fold increase in SA through this
Small intestine resection due to congenital anomalies or NEC causes malabsorption - short gut syndrome
What is the essential secretary components of the intestine?
- Water for fluidity/enzyme transport/absorption
- Ions e.g. duodenal HCO3
- Defence mechanism against pathogens/harmful substances/antigens
What is chronic diarrhoea?
4 or more stools per day for more than 4 weeks
What are the causes of chronic diarrhoea?
- Motility disturbance (Toddler diarrhoea, IBS)
- Active secretion (Acute infective diarrhoea, IBD)
- Malabsorption of nutrients-osmotic (Food allergy, coeliac disease, CF)
What causes osmotic diarrhoea?
Movement of water into the bowel to equilibrate the osmotic gradient
Usually a feature of malabsorption
- Enzymatic defect (e.g. 2ndary lactase deficiency)
- Transport defect (e.g. glucose galactose transporter defect)
- Mechanism of action of lactulose/Movicol
Clinical remission with removal of causative agent
What is secretory diarrhoea classically associated with?
Toxin production from Vibrio cholerae (can lose 24L per day) & enterotoxigenic E.coli
Intestinal fluid secretion predominantly driven by active Cl secretion via CFTR
What does nocturnal defecation suggest?
Organic pathology
How is osmotic and secretory diarrhoea differentiated between?
Osmotic
- Small v (generally <200ml/24 hrs)
- Stops in response to fasting
- Osmolarity is high
Secretory
- Large v (>200ml/24 hrs)
- Continues in response to fasting
- Electrolytes like sodium, potassium and chloride are high
In what disorders is fat malabsorption seen?
Pancreatic disease
- Diarrhoea due to lack of lipase & resultant steatorrhea
- Classically CF
Hepatobiliary disease
- Chronic liver disease
- Cholestasis
What is the commonest cause for malabsorption in children especially if they have been exposed to wheat containing foods?
COELIAC DISEASE (autoimmune condition)
- Gluten sensitive enteropathy-wheat, rye and barley
There should be a genetic predisposition to develop coeliac disease and what is the genetic susceptibility?
HLDQ2/DQ8
Not everyone with this genetic susceptibility will develop coeliac disease therefore genetic testing has got a negative predictive value
What are the classical symptoms of coeliac disease?
- Abdominal bloatedness
- Diarrhoea
- Failure to thrive
- Short stature
- Constipation
- Dermatitis herpatiformis
Most common in children with other autoimmune conditions like IDDM & 1st degree relatives
What screening test (serological screen) is done for coeliac disease?
- Anti-tissue transglutaminase
- Anti-endomysial
Serum IgA check
GOLD STANDARD=DUODENAL BIOPSY
If all of what are present then then diagnosis of coeliac disease made w/o biopsy?
- Symptomatic children
- Anti TTG > 10x the ULN
- +ve anti endomysial Abs
- HLA DQ2, DQ8 +ve
If any of the above are not present then proceed to endoscopy (under GA)
What is the treatment of coeliac disease?
- Gluten free diet for life
- Gluten must not be removed prior to diagnosis as serological & histological features will resolve
- In very young <2yrs, rechallenge & re-biopsy may be warranted
- Increased risk of rare small bowel lymphoma in untreated
In a well toddler, what does undigested vegetables in the stool suggest?
Chronic non-specific ‘toddlers’ diarrhoea and it improves with age
What influences birth size and weight?
Maternal size
Placental function
Gestation
- 95% of weight between 20-40 weeks
- 10-16% of body weight as fat
More than genetic make up
Average term infant 3.3 kg
What is energy requirement?
Energy expended + energy deposited in new tissue
Why is infant nutrition so important and what can it depend on?
Characteristic feature is the need to fuel both rapid growth and maintenance
Infants can rapidly become malnourished.
Dependent on carer
High demands for growth and maintenance
infants 100kcal and 2g protein/kg/day
adults 35kcal and 1g protein/kg/day
Low stores (Fat and protein)
Frequent illness
What are the advantages of breast feeding?
Nutritionally complete feed for full term babies:
Well tolerated
Less allergenic
Low renal solute load
Ca:PO4, Iron, LCP FAs
Improves cognitive development
Reduces risk of infection:
Macrophages and lymphocytes
Interferon, lactoferrin, lysozyme
Bifidus factor
Breast milk further advantages?
‘Unique & perfect’ nutrition
for 6 months
‘near-perfect’ nutrition for up
to a year (preterms)
Tailor-made passive immunity
Increased Development of infant’s active immunity
Increased Development of infant’s gut mucosa
Reduced infection
Antigen load minimal
Reduces risk of breast cancer
In terms of nutrition what is used in premature babies?
Human milk fortifiers as a dietary supplement particularly among those born under 33 weeks
What should be done if breast feeding is not possible?
Families who formula feed should be supported to do so as safely as possible
Standard formula are cows milk based
Various brands available
- No significant difference
- Use whey dominant “first milks”
Powder or ready to feed
Various compositions based on age
What feeds can be used in cow milk protein alergy?
1st line=Extensively hydrolysed protein feeds
2nd line=amino acid based feeds- first line for babies with severe colitis/enteropathy/symptoms on breast milk
What is lactose intolerance?
Not an allergy
Reduced levels of lactase enzyme
Lactose free milks are not CMP free
When should solid food be introduced to babies and why?
At around 6 months
Milk alone inadequate
- Variety of solids provide a source of protein, energy, vitamins, minerals and trace elements
- Encourage tongue and jaw movements in preparation for speech and social interaction
What is neophobia?
Normal part of child development
To reject novel or unknown foods in childhood
Associated with maternal neophobia
Increase acceptance by repeatedly offering a variety of foods
(constipation, anaemia and GOR may be a factor)
What is the difference between GOR & GORD?
GOR=effortless passage of gastric contents into oesophagus with or without regurgitation and vomiting.
GORD=when the reflux of gastric contents causes troublesome symptoms and/or complications
Vomiting is common in babies and is a physiological phenomenon (effortless vomiting with no discomfort: does it need tested?
Does not need special tests or affect growth
Lots of babies regurgitate 1-4 x daily or more
- Peaks at 3-4 months
- Improve from 6 months with solids and sitting upright
When is the earliest you can start weaning?
Minimum 17 weeks
What are red flags in reflux/vomiting?
Weight loss or poor weight gain
Recurrent or bilious vomiting
GI bleeding
Persisting diarrhoea
Dysphagia
Stridor / cough / hoarseness
High risk groups=Preterm babies, neurological impairment, chronic respiratory illness, anatomical, some genetic disorders e.g. Down’s syndrome
How is GORD treated?
Medical referral
Require acid suppression-Reduced gastric acid may increase risk of pneumonia, gastroenteritis and candidiasis
Trial of milk free diet
Continuous NG/jejunal feeds
Consideration of anti reflux surgery
Drug therapy
- Alginate therapy e.g. Gaviscon liquid
- H2 receptor e.g. Ranitidine
- PPIs
- Prokinetics (Need ECG prior to use)
Colic is a diagnosis of exclusion but what are the signs of it?
Inconsolable crying in a baby
- <3 months of age, >3hours/day, >3 days/week
- For at least a week
No red flag symptoms
- Explanation and reassurance
- Probiotics
- Trial of cows milk protein avoidance
- Lactase drops
- Anti spasmodics
What is normal bowel function defined as?
Normal to open bowels from 3 x a day to 3 x a week
- Aim for type 4 stools
(constipation can occur at any age)
How does constipation present?
No bowel movement for three or more days
- Passing lots of small hard stools
Holding on to stools:
- pushing with signs of or her face becoming red
- using avoidance techniques
Soiling, loose stools that leak into pants, pyjamas and bedclothes. This happens when the bowel is full.
How is constipation treated?
- LAXATIVES (lactulose in infants, Movicol/laxido in older children)
- Adequate fluid intake encouraged
- Fruit, veg and wholegrains intake encouraged
- Constant routine & encouragement
What supplement should all babies from birth to 1 yo be given unless have infant formula >500ml?
8.5-10ug Vit D
Everyone over 1 yo should take 10ug Vit D
What is the most important determinant of iron status throughout infancy?
Iron status at birth
(Factors associated with lower iron status at birth include low infant birthweight, and maternal iron deficiency anaemia, obesity, smoking status and gestational hypertension)
Periods of peak brain development:
- Neonatal period
- 6 months to 3 yrs
- May need to ask GP to check FBC/ferritin
What are the causes of iron deficiency?
Breast fed / Pre term
Cow’s milk
- Introducing cow’s milk as a drink before 1 year of age
- No more than 500ml to drink after 1 year of age
Too much juice
- Drink after meals and with snacks
- Only milk and water are tooth friendly
No structure to meals /snacks & offering choices ++
What are possible nutrition issues beyond infancy?
Toddler and Pre-School:
- Learning to feed self and find food Picky eaters/excess milk
- Dependent on carer
- Frequent illness
School age:
- Learning to be independent
- Chronic disease
- Obesity
Adolescent:
- Independent, puberty, eating disorders
