Gastro Flashcards
type of CMPA
- IgE mediated - type 1 hypersensitivvity reaction, atopy related
- non IgE mediated - activates T cells (osmotic diarrhoea due to damage to absorptive area)
presentation of CMPA
GI symptoms within 2 hours of cows milk in first 4 weeks of life
wheeze/ rhinitis
atopic eczema/ rash
crying, irritable, milk refusal
failure to thrive
blood in stool - non IgE mediated
presentation of GORD
excessive regurg or vomiting
irritability e.g. back archin
faltering growth
excessive hiccups
apnoeas/ breath holding/ cyanotic episodes
what is sandifers syndrome
abnormal posturing + deviation of head and neck + discomfort with feeds
needs upper GI endoscopy
GORD diagnosed
clinical diagnosis but can do ph study or barium swallow
ph < 4 for 15 secs
management of GORD
- lifestyle - feed upright, reduce feed volume
- add feed thickener for 1-2 weeks e.g. carobel, gaviscon
- add PPI for 4 week trial if flatering growth
- add domperidone
- fundoplication
type of bacteria h.pylori
gram negative flagellated bacteria
(lipopolysaccharide layer, O antigen and lipid A)
releases urease to neutralise stomach acid and releases toxins to mucosal damage
presentation of h.pylori
dysspepsia
epigastric pain and tenderness
nausea
intolerance of fatty food
diagnosis of h.pylori
- urea breath test *- detects CO2 (h.pylori produces urease to convert urea to ammonia + CO2)
- stool antigen test
- endoscopy - affects lesser curvature of stoamch
management of h.pylori
omeprazole + amoxicillin + metro/ clarithromycin for 1-2 weeks (4 weeks if haematemesis)
what is zollinger ellison syndrome
ectopic gastrin secrteion from a gastrinoma
multiple peptic ulcers >2cm diameter
lining og stomach
columnar epithelium
function of parietal cells
produce HCl + intrinsic factor
function of G cells
produce gastrin
function of enterochromaffin like cells
produce histamine (binds to parietal cells to activate)
function of D cells
produce somatostatin which inhibits gastrin secretion
function of mucus neck cells
produce bicarbonate and mucus
function of chief cells
produce pepsinogens
epidemiology of coeliac
1% population
risk factors for coeliac
- HLA-DQ2 or DQ8
- 1st degree family
- autoimmune disease e.g. vitiligo (lack of melanocytes in epidermis)
-Ig A deficiency - Downs syndrome
- Turner syndrome
presentation of coeliac
GASTRO - abdo pain and distension, diarrhoea, vomiting, buttock wasting, constipation, faltering growth
SKIN - dermatitis herpetiformis, aphthous stomatitis, vitiligo
OTHER - vit b12 deficiency, dental enamel defects, iron deficiency, dilated cardiomyopathy
diagnosis coeliac disease
IgA tissue transglutaminase positive*** +/- anti endomysial antibodies
if IgA deficiency -> test IgG ttG
if <10 x maximum, upper Gi endoscopy and duodenal biopsy
findings on duodenal biopsy of coeliac disease
intra epithelial lymphocytosis ***
subtotal villous atrophy
crypt hypertrophy
lamina propria cell infiltrate
enteropathy
complications of coeliac
amenorrhoea
delayed puberty
osteopenia and osteoporosis
hyposplenism
T cell lymphoma
risk factors of pyloric stenosis
male ** -first born
first degree relative (female pass on higher risk)
prematurity
maternal smoking
IUGR
macrolide abx use
presentation of pyloric stenosis
present 4-6 weeks of life with…
projectile vomiting
hungry baby
weight loss
dehydration
palpable olive shaped mass in RUQ
investigations pyloric stenosis
- gas - metabolic alkalosis - hypokalaemia, hypochloraemia
- USS abdomen - wall thickness 4mm, length 17mm, diameter 15mm
management of pyloric stenosis
- rehydration with IVF prior to surgery
- surgical correction with Ramstedt pylomyotomy
viral causes of gastroenteritis
- rotavirus - childcare settings, cause dehydration, doubel stranded rNA virus
- noravirus - healthcare
- adenovrirus
bacterial causes of gastroenteritis
- salmonella - poulty (typhi - travel abroad + salmon pink rash)
- campylobacter *
- e.coli - undercooked meat
- shigella
- staph aureus -ingestion of inadequately reheated food
- cholera - vibrio cholerae, large volume, rice water stools
risk of e.coli enterotoxi 0157
haemolytic uraemic syndrome - reduced renal function + pale + anaemia + bloody stool
type of diarrhoea
- osmotic diarrhoea = damage to intestinal microvilli causing malabsorption, if stop eating, diarrhoea stops
- secretory = enterocyte binding toxin causing release of Cl into intestinal lumen, even if continue eating, diarrhoea continues
type of fluid loss
- hypotonic - highly concentrated urine, high sodium, causes water depletion
- isotonic - water and Na loss causing increased haematocrit
most common sites of crohns
proximal colon and terminal ileum
presentation of crohns
- GI - diarrhoea, abdo pain, weight loss , growth failure, mouth ulcers
- skin - erythema nodosum, pyoderma gangrenosum , psoriasis
- blood - iron deficiency
- eye - episcleritis
- bone - ank spondylitis, sacroilitis, osteoporosis
diagnosis of crohns
upper and lowe endoscopy + biopsy *
non caseating granulomas, multiple lymphoid aggregates, transmural inflammation with skip lesions, fissures, strictures, aphous / linear ulcers
inducing remission in crohns disease
- 1st presentation = glucocorticoids e.g. prednisolone , methylpred, IV if severe
- 6 week enteral nutrition (protein based formula,polymeric 1st line)
- 5-ASA
- azathioprine
maintenance therapy in crohns
1st line = AZATHIORPINE
side effects:
myelosuppression
pancreatitis
hepatitis
indications for surgery in crohns
- ileocaecal disease
- strictures
- fissures
- failure of medical treatment
pathophysiology of UC
diffuse continuous inflammation of intestinal mucosa (usually rectal and colon) and exaggerayed T cell response
associated with HLA-DRB in extensive disease
90% pancolitis !!!!
presentation of UC
- bloody diarrhoea
- night stools
- abdo pain
- weight loss
- erythema nodoum
- iritis, uveitis
-sclerosing cholangitis - autoimmune hepatitis
- arthritis
diagnosis of UC
endoscopy and biospy (sigmoid colon **)
friable mucosa, submucosal and mucosal inflammation, crypts abscesses, goblet cell depletion, ulceration
affects the mucosa layer
complications of UC
toxic megacolon - fever, tachycardia, dilated transverse colon
colon cancer
oxalate renal stones
osteoporosis
management of UC
induction: mesalazine (5-ASA)
maintenance: mesalazine or sulfasazlaline
15% require surgery 5 years from diagnosis
pathophysiology of duodenal atresia
abnormal developement of intestine - failure of canalization of duodenum at 7 weeks gestation
usually occurs at ampulla of vater
associations with duodenal atresia
trisomy 21
prader willi
congenital heart disease
CF
diaphragmatic hernia
presentation of duodenal atresia
present in 1st few days of life with bilious vomiting (non bilious in 20% if above ampulla of vater)
abdo distension
antenatal signs of duodenal atresia
polyhydramnios
double bubble sign of USS
management of duodenal atresia
- NG tube - decompress stomach, NBM
- duodenoduodenostomy by open laparotomy
pathophysiology of necrotising enterocolitis
acute inflammatory injury of small intestine and invasion of enteric organisms and causing ischaemic necrosis of intestinal mucosa
commonly affects terminal ileium, caecum and sigmoid colon
factors contributing to necrotising enterocolitis
- premature gut motility
- reduced igA and reduced barrier function -> initiate mucosal injury _> invasion of gas producing bacteria
- gut hypoxia
- metabolic substarte in gut lumen
risk factors for necrotising enterocolitis
- prematurity (<32 weeks)
- low birth weight , iUGR
- hypothermia
- PROM
- artificial feeds or rapid increase in enteral feeds
- placenta insufficicency, abruption
presentation of necrotising enterocolitis
feed intolerance with gastric residuals
bilious vomiting, diarrhoea
rectal bleeding
abdo distension, abdo tenderness
leading to perforation and shock, mortality 10%
investigations for necrotising enterocolitis
- abdo x ray - pneumoperitoneum, portal venous gas, bowel wall oedema, intramural gas of nitrogen and hydrogen (= pneumatosis intestinalis)
- blood cultures
- gas - metabolic acidosis, high lactate
management of necrotising enterocolitis
- NBM
- NG suctioning
- parental nutrition and IVF
- IV antibiotics 14 days
- +/- surgery if perforation or failure of medical treatment
what is hirschsprungs disease
absence of ganglion cells in the distal part of colon and rectum due to failure of neural crest cells (derived from neuroectoderm) to migrate and populate distal colon
associations with hirschsprungs disease
- downs syndrome
- waardenburg syndrome
- bardet biedl
- males
- mutations in RET and EDNRB
pathophysiology of hirschsprungs disease
lack of ganglion cells in submucosa and myenteric plexus (auerbach ) muscular layer causes….
1. functional obstruction as no contraction of muscles
2. enterocolitis - stool accumulates and causes extension of proximal bowel and bacetria