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 causes of neonatal hepatitis are there?
- alpha-1-antitrypsin deficiency
- galactosaemia
- tyrosinaemia
- urea cycle defects
- haemochromatosis
- glycogen storage disorders
- hypothyroidism
- viral hepatitis
- parenteral nutrition
