alimentary Flashcards
what are the different phases of vomiting
pre-ejection phase
ejection phase
post-ejection phase
what are the clinical features of each phase
pre ejection: pallor, nausea, tachycardia
ejection: retch, vomit
post ejection: weakness, shivering, lethargy
what causes vomiting?
stimulation of vomiting centre in medulla triggered by:
- enteric pathogens
- infection
- visual/olfactory stimuli - fear
- head injury/raised ICP
- inner ear stimuli
- metabolic derangements/chemotherapy
what are the different types of vomiting?
- vomiting with retching
- projectile vomiting
- bilious vomiting
- effortless vomiting
- haemetemesis
what are the causes of vomiting?
infants: GOR, cow’s milk allergy, infection, intestinal obstruction
children: gastroenteritis, infection, appendicitis, intestinal obstruction, raised ICP, coeliac disease
young adults: gastroenteritis, infection (H. Pylori), appendicitis, raised ICP, DKA, cyclical vomiting syndrome, bulimia
describe presentation of pyloric stenosis
babies 4 - 12 weeks boys > girls projectile non-bilious vomiting weight loss dehydration +/- shock electrolyte disturbance: metabolic alkalosis (↑pH), hypochloraemia (↓Cl), hypokalaemia (↓K)
what are the investigations for pyloric stenosis
- test feed
- blood gases: hypokalemic, hypocholermic metabolic alkalosis after prolonged vomiting
what is the management for pyloric stenosis
fluid resuscitation
refer to surgeons if obstruction
describe effortless vomiting
due to gastro-oesophageal reflux
self-limting
symptoms:
- vomiting, haematemesis
- nutritional: feeding problems, failure to thrive
- respiratory: apnoea, cough, wheeze, chest infections
- neurological: sandifer’s syndrome
what are the investigations for effortless vomiting
history and examination
oesophageal pH study/impedance monitoring
endoscopy
imaging: video fluoroscopy, barium swallow
what is the management for effortless vomiting
feeding advice: thickeners, feeding position & volumes
nutritional support: calories supplements, exclusion diet, nasogastric tube, gastrostomy
medical treatment (rare): prokinetic drugs, acid suppressing drugs, H2 receptor blockers, proton pump inhibitors
surgery (rare): nissen fundoplication
what should bilous vomiting always be presumed to be due to?
intestinal obstruction until proved otherwise
ALWAYS ring alarm bells
what are the causes of bilious vomiting
intestinal atresia (in newborn babies only) malrotation intussusception ileus crohn’s disease with strictures
what are the investigations for bilious vomiting
abdominal x-rays
consider contrast meal
surgical opinion regarding laparotomy
what is the fluid balance of the GI system?
9L fluid enters duodenum
1.5L gets to colon
<200ml lost in faeces
how is the surface area of the small intestine increased?
mucosal folds
villi
What is there increased risk of in untreated coeliac disease?
Small bowel lymphoma
what is the definition of chronic diarrhoea?
4 or more stools per day for more than 4 weeks
- <1 week: acute diarrhoea
- 2 - 4 weeks: persistent diarrhoea
- > 4 weeks: chronic diarrhoea
what can cause diarrhoea?
motility disturbance: toddler diarrhoea, irritable bowel syndrome
active secretion: acute infective diarrhoea, inflammatory bowel disease
malabsorption of nutrients: food allergy, coeliac disease, cystic fibrosis
what types of diarrhoea are there?
osmotic
- movement of water into bowel to equilibrate osmotic gradient
- usually a feature of malabsorption (enzymatic defect or transport defect)
- mechanism of action of lactulose/movicol
secretory
- classically associated with toxin production from vibrio cholerae and enterotoxigenic Escherichia coli
- intestinal fluid secretion predominantly driven by active Cl- secretion via CFTR
what drives intestinal fluid secretion in secretory diarrhoea?
intestinal fluid secretion predominantly driven by active Cl- secretion via CFTR
what is the clinical approach to chronic diarrhoea?
history: age, abrupt/gradual onset, family/travel history
growth and weight gain of child
faeces analysis: appearance, stool culture, determination of secretory vs osmotic
what types of disease does fat malabsorption occur in?
pancreatic disease
- lack of lipase and resultuant steatorrhoea; clasically cystic fibrosis
hepatobiliary disease
- cholestasis; clasically chronic liver disease
how does coeliac disease present in children?
- abdominal bloatedness
- diarrhoea
- failure to thrive
- short stature
- constipation
- tiredness
- dermatitis herpatiformis
what screening tests are there for coeliac disease?
serological screens
- anti-tissue transglutaminase
- anti-endomysial
- anti-gliadin
- IgA screen
duodenal biopsy (gold standard)
genetic testing
-HLA DQ2, DQ8
what histological characteristics are associated with coeliac disease?
lymphocytic infiltration of surface epithelium
partial /total villous atrophy
crypt hyperplasia
what guidelines determine whether a biopsy is required to diagnose coeliac disease?
ESPHGHAN/BSPGHAN
- symptomatic children
- anti TTG >10 times upper limit of normal
- positive anti endomysial antibodies
- HLA DQ2, DQ8 positive
if all present -> diagnosis
if not all present -> endoscopy -> diagnosis
what is the treatment for coeliac disease?
gluten-free diet for life
gluten must not be removed prior to diagnosis as serological and histological features will resolve
in very young <2yrs, re-challenge and re-biopsy may be warranted
what are the essential secretory components
water for fluidity, enzyme transport, absorption
ions
defense mechanism against pathogens/harmful substances/antigens
how has the incidence of Crohn’s disease changed in Scottish children?
dramatically increased and continues to
what are the presenting features of Crohn’s in children?
- weight loss
- growth failure
- abdominal pain
- diarrhoea
- rectal bleeding
- arthritis
- mass
- fever
what are the presenting features of UC in children?
- diarrhoea
- rectal bleeding
- abdominal pain
- arthritis
- fever
- weight loss
- growth failure
- no mass
what history and examination is required when diagnosing IBD?
intestinal symptoms extra-intestinal manifestations: erythema nodosum exclude infection family history growth and sexual development nutritional status
what laboratory investigations should be carried out?
full blood count & ESR: anaemia, thrombocytosis, raised ESR
biochemistry: stool calprotectin, raised CRP, low Albumin
microbiology: no stool pathogens
how does Crohn’s usually present in children?
- lack of specific symptoms (present with weight loss and growth failure)
- abnormal blood tests and high calprotectin
how does UC usually present in children?
- symptomatic with bloody diarrhoea
- do not necessarily have abnormal growth or blood tests
- high calprotectin
what are the definitive radiological investigations for IBD?
- MRI (usually >5 years due to the need to keep still without a GA)
- barium meal and follow through (younger kids)
what types of endoscopy are used in the definitive diagnosis of IBD?
- colonoscopy
- upper GI endoscopy
- mucosal biopsy
- capsule endoscopy
- enteroscopy
what are the aims of treatment in IBD?
- induce and maintain remission
- correct nutritional deficiencies
- maintain normal growth and development
What are the treatment for IBD in children?
Medical
- Anti-inflammatory
- Immuno-suppressive
- Biologicals ( Infliximab)
Nutritional
- Immune modulation
- Nutritional supplementation
- Milkshake diet
Surgical
what is constipation?
infrequent passage of stool
what do you want to know about the child presenting with constipation?
- frequency
- hardness
- painful
- has there been a change?
what is normal stool frequency?
4 per day to 1 per week
what does stool frequency depend on?
- age
- diet
what are the components of the Bristol stool chart?
- type 1 = separate hard lumps
- type 4 = smooth sausage like
- type 7 = entirely liquid
what are other signs and symptoms of constipation?
- poor appetite
- irritable
- lack of energy
- abdominal pain or distension
- withholding or straining
- diarrhoea
- urinary issues
- pale with bags under their eye
Why do children become constipated?
social: poor diet (lack of fluid, excess milk), potty training/toilets issue
physical: intercurrent illness, medications (opiates and gaviscon)
psychological
organic
what is the vicious cycle of constipation?
- large hard stool
- leads to pain and fissuring
- child withholds stool
- becomes constipated
how does overflow diarrhoea develop?
- child enters the vicious cycle of constipation
- rectum tells them they need to go but the child clenches the external sphincter
- poo continues to be dehydrated by bowel becoming harder
- back passage begins to stretch and creates a mega rectum
- soiling occurs when the mega rectum holds the internal sphincter open and the child is unable to clench the external sphincter
what is the treatment of constipation
social
- explain treatment to parents
- dietary: increase fibre, fruit, vegetables, fluids, decrease milk
psychological
- reduce the aversive factors by making going to the toilet a pleasant
- reward good behaviour
soften stool and stimulate defecation
- osmotic laxatives (lactulose)
- stimulant laxatives (senna, picosulphate)
- isotonic laxatives (movicol, laxido)
give enough to make them go and make sure stool is always soft and never painful; until no longer is required
how is impaction treated?
- empty impacted rectum
- empty colon
- maintain regular stool passage
- slow weaning off treatment
- ensure compliance
what are the functions of the liver?
- waste handling
- water handling
- salt balance
- acid base control
- endocrine: produces albumin, clotting factors
what is included in LFTs?
- bilirubin (total and split)
- ALT/AST (alanine aminotransferase/aspartate aminotransferase)
- alkaline phosphatase
- gamma glutamyl transferase (GGT)
when is ALT/AST elevated?
in hepatocellular damage (hepatitis)
when are alkaline phosphatase and GGT elevated?
biliary disease
what tests are used to assess the function of the liver?
- coagulation (prothrombin time (PT)/INR, APTT)
- albumin
- bilirubin
- blood glucose
- ammonia
how can paediatric liver disease manifest?
- jaundice
- incidental finding of abnormal blood test
- symptoms/signs of chronic liver disease
what are the signs of chronic liver disease in children?
what is jaundice?
yellow discolouration of skin and tissues due to accumulation of bilirubin
usually most obvious in sclera; visible when total bilirubin >40-50 umol/l
what is diagnosis of infant jaundice dependent on?
- bilirubin metabolism
- age
how is bilirubin metabolised?
- post mature RBC broken down in the reticuloendothelial system to bilverdin
- converted to unconjugated bilirubin
- bound to albumin and conjugated in the liver
- mixes with bile in gallbladder and enters small intestine
- converted to urobilinogen and excreted by the kidneys as urine or in faeces
what is the solubility of bilirubin?
conjugated: water soluble/ fat insoluble
unconjugated: water insoluble/ fat soluble
describe the conjugation of bilirubin and jaundice
pre hepatic: unconjugated bilirubin (excess)
intra hepatic: mixed bilirubin (liver issues)
post hepatic: conjugated bilirubin (obstruction: cholestasis)
describe neonatal jaundice?
early (<24 hours old): haemolysis, sepsis (always pathological)
intermediate (24 hours - 2 weeks): physiological, breast milk, haemolysis
prolonged (>2 weeks): extrahepatic obstruction, neonatal hepatitis, hypothyroidsim, breast milk
why does physiological jaundice occur?
- develops after the 1st day of life as it takes time for RBC to break down
- shorter RBC life span in infants (80-90 days)
- relative polycythaemia
- relative immaturity of liver function
what type of jaundice is physiological jaundice?
unconjugated
why does jaundice occur with breast fed babies?
exact reason for prolongation of jaundice in breastfed infants unclear
what type of jaundice is breast milk jaundice?
unconjugated
how long can breast milk jaundice persist?
up to 12 weeks from birth
apart from breast milk and physiological what other causes of unconjugated infant jaundice are there?
- sepsis
- haemolysis (excessive)
- abnormal conjugation
why might there be excessive haemolysis in a baby leading to jaundice?
- ABO incompatibility
- rhesus disease
- bruising/cephalhaematoma
- red cell membrane defects (e.g. spherocytosis)
- red cell enzyme defects (e.g. G6PD)
what causes of abnormal conjugation are there?
- gilbert’s disease (common, mild)
- crigler-aajjar syndrome (very rare but sever)
what are the investigations for jaundice?
- urine culture
- blood culture
- TORCH screen
- blood group
- DCT
- clinical examination
- blood film
- G6PD assay
- genotype/phenotype
what is a possible complication of unconjugated jaundice?
kernicterus
unconjugated (fat-soluble) bilirubin crosses blood-brain barrier and deposits in brain (particularly the basal ganglia); it is neurotoxic
what are the signs of kernicterus?
early: encephalopathy, poor feeding, lethargy, seizures
late: choreoathetoid cerebral palsy, learning difficulties, sensorineural deafness
how is unconjugated jaundice treated?
phototherapy: visible light (450nm wavelength) converts bilirubin to water soluble isomer (photoisomerisation)
what is prolonged infant jaundice?
jaundice persisting beyond 2 weeks of life or 3 weeks of life in preterms
what are the causes of prolonged infant jaundice?
conjugated: anatomical (biliary obstruction), neonatal hepatitis
unconjugated: hypothyroidism, breast-milk jaundice
what causes of biliary obstruction can lead to prolonged jaundice?
biliary atresia: pale stools
choledochal cyst: pale stools
alagille syndrome: intrahepatic cholestasis, dysmorphism, congenital cardiac disease
what is biliary atresia?
congenital fibro-inflammatory disease of the bile ducts leading to destruction of extra-hepatic bile ducts
pale stools, dark urine, liver failure
investigation: split bilirubin, stool colour, ultrasound, liver biopsy
treatment: kasai portoenterostomy
what is the most common indication for liver transplant in children?
biliary atresia
what investigations are done for choledochal cyst?
- split bilirubin
- stool colour
- ultrasound
what investigations are done for Alagille syndrome?
- dysmorphism
- genotype
what causes of neonatal hepatitis are there?
- alpha-1-antitrypsin deficiency
- galactosaemia
- tyrosinaemia
- urea cycle defects
- haemochromatosis
- glycogen storage disorders
- hypothyroidism
- viral hepatitis
- parenteral nutrition
what should you always ask about with prolonged infant jaundice?
stool colour
what is the most important test for prolonged infant jaundice?
split bilirubin to determine if it is conjugated or unconjugated in nature
what is the main diagnosis to exclude with conjugate prolonged jaundice?
biliary atresia
what jaundice requires further investigation
conjugated jaundice is always abnormal and requires further investigation
most important test = split bilirubin
what are the recognised phases of childhood?
- neonate (<4w)
- infant (<12m/1y)
- toddler (~1-2y)
- pre-school (~2-5y)
- school age
- teenager/adolescent
what drives infant growth?
nutrition
what drives child growth?
growth hormone
what drives pubertal growth?
sex steroids
why is nutrition important?
- required for changes in brain and body structure, composition and function
- prevention of malnutrition and disease
What is birth size and weight dependent on?
- Maternal size
- Placental function
- Gestation
What is the average weigth of a term infant?
3.3kg
What is energy needed for?
- Physical activity
- Thermogenesis
- Tissue maintenance
- Growth
What is the growth demands of infants?
About 35% of energy intakee
Why can infants rapidly become malnourished?
- high demands for growth and maintenance
- low stores (protein and fat)
- frequent illness
What is the average weekly weight gain of infants?
- 0-3months 200g
- 3-6 months 150g
- 6-9 months 100g
- 9-12 months 75-50g
What are the benefits of breast feeding?
- nutritionally complete for full term babies
- improves cognitive development
- reduces risk of infection
- tailor made passive immunity
- increase in development of gut mucosa/active immunity
- decreased risk of breast cancer
Why does breast milk reduce infection?
Contains
- Macrophages and lymphocytes
- Interferon, lactoferrin ad lysozyme
- Bifidus factor
what are the advantages of formula feeding?
- no transfer of BBVs or drugs
- accurate feed volumes
- provides vitamin K
- less jaundice
what are the disadvantages of formula feeding?
- no anti-infection properties
- risk of contamination
- high antigen load
- expensive
What are UNICEF’s baby friendly 10 steps?
- Written breast feeding policy
- Train all staff to implement policy
- Inform all pregnant women about benefits of breast feeding
- Help mothers initiate breast-feeding (within 30mins of birth)
- Show mothers how to breastfeed
- Give new-borns only breast milk
- Practise rooming
- Encourage on demand feeding
- No teats or dummies
- Advocate breast feeding support groups
What happens if breast-feeding is not possible?
- Formula feeding is common
- All are cows milk based
- Based on age
Why is cows milk not suitable as the main drink for <1 years?
Contains almost no iron
When is milk the exclusive feed?
For the first 4-6 months
What type of specialised formulas are there?
- Cows milk protein allergy
- Nutrient dense
- Disease specific
What formula is available for pre-term infants?
- SMA Gold Prem
- Typically 2g (vs 1.5) protein and 80kcal (vs 68)/100ml
- Post discharge prescribable eg Nutriprem 2
What nutrient dense formula is available?
- Infatrini/SMA High Energy
- 100kcal/100ml ,prescribable to 18 months
What type of reaction is CMPA?
Majority are delayed, non IgE reactions
How can CMPA present?
- Vomiting
- Diarrhoea
- Abdominal discomfort
- Abdominal distension
- Eczema
What is the test for CMPA?
Exclusion of CMPA
What is the CMPA pathway?
- 4 week trial of milk avoidance
- Special formula or milk free diet for breast feeding mums
- Reintroduction at 4 weeks unless clear benefit
- Re challenge after 6 months of improvement
- Milk ladder approach
What is the milk ladder approach?
Not all forms of milk are equally allergenic
- Cookie/biscuit
- Muffin
- Pancake
- Cheese
- Yoghurt
- Pasteurised milk/infant formula
What is the first line feed choice in CMPA?
- Extensively hydrolysed protein feeds
- 90% should respond (10% react)
- Palatability a problem in older babies
- Nutramigen LGG Lipil 1 and 2
- Aptamil Pepti 1 and 2
What is the second line feed choice in CMPA?
- Amino acid based feeds
- Babies with severe colitis/enteropathy/ symptoms on breast milk
- Overprescribed and expensive
What is lactose intolerance?
- NOT AN ALLERGY
- Reduced levels of lactase enzyme
Who can lactose intolerance be seen in?
- Seen to minor degree in some breast fed babies
- Post gastro enteritis (Transient and self resolving)
- Also in certain ethnic groups post weaning
What is secondary lactose intolerance?
- Short lived condition eg post gastro-enteritis
- Confused with cow’s milk protein intolerance
- Lactose free/ “Comfort” milks are not CMP free
What are the indications for soya milk?
- Milk allergy when hydrolysed formulae refused
- Vegan families, if not breast fed
- Consider for children>1 year still on milk free diet
Why should soya milks be avoided in infants?
- They contain phytoestrogens
- Cross reactivity with cows milk
What non formula milks can be introduced into children’s diets?
- Rice Milk (Not advised for children under 5 years)
- Goats’ and Sheep’s milk (Not suitable for under 1’s, Many children will react)
- Oat and nut milks
- Organic versions are not calcium fortified
What is the nutritional value of full fat cows milk?
- 65kcal/100ml and 120 mg calcium/100ml
- Organic/ unsweetened milk substitutes low in calories
- Organic milks are no calcium supplemented
How much milk is required to meet daily requirements?
- Need 400-500ml of a calcium fortified “milk” to meet calcium requirements
- Supplement if <500ml calcium fortified substitute
What types of calcium supplements are available?
- Alliance calcium liquid or (if >3y) Calcium softies
- For breast feeding mums Accrete or Cacit D3
What is weaning?
Transition from milk to a mixed diet
When does weaning occur?
Starts around 6 months
Why do we wean children?
- Milk alone is inadequate
- Source of vitamins and trace elements
- Man is an omnivore
- Encourage tongue and jaw movements in preparation for speech and social interaction
Who in particular requires vitamin D?
- Dark skinned children, who breast feed from mum not on supplements
- Scots (unable to synthesis from September to April)
Who should receive supplements?
- All breast fed babies from 1 month
- Bottle fed babies taking <500ml formula
- All children from 1-4 years
What nutrition issues are there beyond infancy?
- Picky eaters
- Frequent illness
- Dependence on carer
- Learning to be independent
- Chronic disease
- Obesity
- Puberty
- Eating disorders
what is constipation?
infrequent passage of stool
what do you want to know about the child presenting with constipation?
- frequency
- hardness
- painful
- has there been a change?
what is normal stool frequency?
4 per day to 1 per week
what does stool frequency depend on?
- age
- diet
what are the components of the Bristol stool chart?
- type 1 = separate hard lumps
- type 4 = smooth sausage like
- type 7 = entirely liquid
what are other signs and symptoms of constipation?
- poor appetite
- irritable
- lack of energy
- abdominal pain or distension
- withholding or straining
- diarrhoea
- urinary issues
- pale with bags under their eye
Why do children become constipated?
social: poor diet (lack of fluid, excess milk), potty training/toilets issue
physical: intercurrent illness, medications (opiates and gaviscon)
psychological
organic
what is the vicious cycle of constipation?
- large hard stool
- leads to pain and fissuring
- child withholds stool
- becomes constipated
how does overflow diarrhoea develop?
- child enters the vicious cycle of constipation
- rectum tells them they need to go but the child clenches the external sphincter
- poo continues to be dehydrated by bowel becoming harder
- back passage begins to stretch and creates a mega rectum
- soiling occurs when the mega rectum holds the internal sphincter open and the child is unable to clench the external sphincter
what is the treatment of constipation
social
- explain treatment to parents
- dietary: increase fibre, fruit, vegetables, fluids, decrease milk
psychological
- reduce the aversive factors by making going to the toilet a pleasant
- reward good behaviour
soften stool and stimulate defecation
- osmotic laxatives (lactulose)
- stimulant laxatives (senna, picosulphate)
- isotonic laxatives (movicol, laxido)
give enough to make them go and make sure stool is always soft and never painful; until no longer is required
how is impaction treated?
- empty impacted rectum
- empty colon
- maintain regular stool passage
- slow weaning off treatment
- ensure compliance
