GI disease Flashcards
what are the 2 phases of digestion
luminal
mucosal/membraneous
what is epi
inadequate secretion of pancreatic enzymes
maldigestion
steatorrhoea
what is biliary disease
failure of emulsification
lipase works but unable to solubilise lipids in micelles
maldigestion
what is ileus
inhibition of smooth muscle causing decrease in motility
clinical signs of intestinal disease
diarrhoea
vomiting
abdo pain/discomfort
weight loss
anorexia
flatulence
borborygmi
constipation
tenesmus
melaena or haematochezia
what defines diarrhoea
passing faeces with increased volume and/or frequency
categories of diarrhoea
osmotic - maldigestion, malabsorption
secretory - toxin, infection related
inflammatory - IBD
motility disorder
infectious - bacteria eg, salmonella, viral, parasites
investigation into intestinal disease
signalment
history
PE
haematology/biochemistry - cause/effect
faecal analysis
management of diarrhoea
fluids
electrolytes
control losses - vomiting/regurgitation
analgesia
anti-emetics
gut protectants
Acid base disturbances
can cause metabolic alkalosis/acidosis
SI diarrhoea - metabolic acidosis
severe vomiting - metabolic alkalosis
in all - manage underlying cause and restore renal perfusion
what causes jaundice
hyperbilirubinaemia >50umol/L
what is bilirubin
product of haemoglobin metabolism
haemoglobin > heme>biliverdin>bilirubin
how does bilirubin appear on excretion
urobilin - turns urine yellow
stercobilin - turns faeces brown
haemolytic anaemia causes
acquired - hypophosphatemia, oxidative damage
genetic defects - abyssinian/somali cats have hereditary haemolysis
non-spherocytic in beagles, phosphofructokinase in spaniels
immune mediated
mechanical injury - turbulent blood flow neoplasia
Types of immune mediated haemolytic anaemia
primary - spontaneous, common in spaniels, diagnosis of exclusion
secondary - drugs/toxins, other immune disease, infection, neoplasia
diagnosis of haemolysis (pre-hepatic)
PCV - anaemia - macrocytic, hypochromic regenerative is classic for haemolysis
blood smear - sperocytosis and auto-agglutination
visual inspection
can develop thrombocytopaenia concurrently
hepatic causes of anaemia
infectious hepatic disease
inflammation - cholangiohepatitis
neoplasia - lymphoma, mct, adenocarcinoma
drugs/toxins - paracetamol, nsaids etc
degeneration - amyloidosis, lipidosis,cirrhosis
proximal biliary disease - cholangitis,cholangiohepatitis
diagnosis of hepatic anaemia
biochemistry
- alt - elevation = hepatocellular damage
- ast - liver/muscle, can raise with venipuncture
- alp - concentrated in biliary tree, small elevations significant in cat as short half life
ggt - biliary tree (and other areas) useful in combination with alp
functional tests
- urea - low values support reduced liver function
- ammonia - high as not converted into urea
- albumin - low values support liver disease
- clotting factors - produced by liver
bile acid stim
imaging - ultrasound/ct, fna/biopsy
post-hepatic causes of jaundice
intraluminal obstuction
mural - inflammation/neoplasia
extra-mural - pancreatic disease, duodenal disease, porta-hepatic stricture
CE/history for jaundice
CE
ecchymoses/bruising
perhipheral oedema
cranial abdo pain
neuro deficits - hepatic encephalopathy
low bcs in chronic
ascites
associated signs for regurgitation
dyspnoea
cough
nasal discharge
associated signs for vomiting
hypersalivation
lip-licking
signs of nausea
hypersalivation
lethargy
anorexia
lip smacking
burping
causes of vomiting
vomiting centre - elevated csf pressure through nausea/inflammation
vestibular apparatus - motion sickness/otitis
perhipheral receptors - git, pancreas, liver, mesentary, peritoneum, urinary tract, heart
chemoreceptor trigger zone - drugs, metabolic disorders, toxins
foreign body vomiting
pathophysiology - obstruction increases pressure and dilates/compromises perfusion leading to inflammation and vomiting
diagnosis - plain/contrast radiography, ultrasound, CT and endoscopy
treat by removal
Intussusception
pathophysiology - vigorous contraction forces segment into the adjacent segment’s relaxed lumen
causes - idiopathic, parasitism, masses, fb
diagnosis - ultrasound
treatment - surgery
maropitant
anti-emetic
NK-1 action
affects the vomiting centre, peripheral receptors and CRTZ
97% effective, avoid with obstruction and reduce dose with hepatic disease
Ondansetron
Anti-emetic
5HT3 action
affects the peripheral receptors and CRTZ
avoid with obstructions
Metoclopramide
Anti-emetic
action on D2 receptors affecting the CRTZ
often used as a cri, coordinated gastric motility (prokinetic) reduce dose in hepatic/renal disease
Differentials for chronic intestinal vomiting
Inflammation
neoplasia
most common
Adenocarcinoma causes of vomiting
signs - chronic vomiting and diarrhoea, malaena, haematemesis, weight loss
CE - lymphadenopathy, abdo mass/pain?
Radiography - abdo mass, constricting lesion
ultrasound - intestinal mass, loss of layering, reduction in motility
diagnosis - biopsy, staging with blood loss/fna
treatment - surgery - 75% have mets at diagnosis
lymphoma cause of vomiting
CS - chronic vomiting/diarrhoea, malaena, haematemesis, weight loss
CE - lymphadenopathy, abdo mass/pain
Radiography - abdo mass/constricting lesion
Ultrasound - thickened abdo wall, loss of intestinal layering, reduced motility
Diagnosis - biopsy/FNA
Treatment - surgery/chemotherapy
Prognosis - 4-18m better in cats
Physiology of vomiting
active reflex mediated via the emetic centre, can be stimulated by the chemoreceptor trigger zone, GI tract, cerebral cortex or vestibular system
lots of systems to consider as cause
acute vs chronic vomiting causes
acute - toxic, obstructive, inflammatory, infectious
chronic - chronic inflammation, chronic infection, metabolic/endocrine and neoplastic
physiology of regurgitation
passive expulsion of food from pharynx/oesophagus
consider anatomy, musculature and neurological systems
oesophagus - sphincters
what is dysphagia
failure to prehend/bite and move to swallow food
pain on opening/closing of the jaw
failure of neuromuscular control
obstruction
regurgitation
failure to pass the oesophagus
dilation - megaoesphagus
obstruction
neuromuscular disorder
gastroprotectants
omeprazole - PPI
Misoprostal - prostaglandin analogue - dont use with pregnancy
H2 receptor agonist - cimetidine - reduce acid secretion
sucralfate - binds damaged mucosa
diagnostic testing
imaging - obstructive/anatomical disease
radiography
ultrasound - pocus for free fluid
haematology/biochemistry
specific blood tests
treatment of ingested toxins in stomach
induce emesis withing 2-8h dog and 2-12h cat
apomorphine in dogs
xylazine/medatomidine isnt licensed but may be used in cats
Intestinal transit of toxins
use adsorbents - activated charcoal, binds toxin for excretion but does cause black faeces
Skin exposure of toxins
decontamination of the skin - washing - take care as prolonged washing can wash in some toxins, take care drying as abrasions can allow toxin
inhaled toxins
cannot decontaminate - take care if retrieving
metabolic toxins
prevention of metabolising once in the blood stream
fluid therapy best
lipid infusion for lipid soluble compunds
body system assessment
neuro - seizures, ataxia, sedation
cardiovascular - arrythmias, tachy/bradycardia, hypo/hypertension
GI - V+/D+
renal - azotaemia/inapprorpiate usg
hepatic - jaundice, alt,alp,bile acids
clotting time/anaemia
Ibruprofen/Nsaid toxicity
reduced prostaglandin production
CS - haemorrhagic V+/D+, aki
treatments - H2 blockers - cimetidine
PPI - omeprazole
Prostaglandin analogue - misoprostal
Aspirin toxicity
prostaglandin inhibition plus thromboxane inhibition (platelet function)
CS - thrombocytopathy
Treatment as NSAIDs
Paracetamol toxicity
NAPQI excess de-toxified by glutathione, stores can be exhausted
excess = hepatic cell necrosis, nephrotoxicity
CS - brown MM, jaundice, abdo pain, lethargy, vomiting, AKI, tissue hypoxia
Treatment
- N-acetyl cysteine - glutathione precursor
- H2 receptor agonists
- vit C
- liver, AKI and GI support
chocolate toxicity
methyl-xanthines increasing catecholamine release, increase cAMP and inhibits adenosine receptors
CS - hyperactivity, V+/D+, arrythmias, seizures, coma, death
Treatment - charcoal 4-6 hourly, can need intubation/urinary catheterisation
Xylitol toxicity
mimics glucose but not broken down in the same way
Stimulates insulin release and is hepatotoxic leading to prolonged hypoglycaemia (12-48h) and liver failure in 72h
CS - weakness, collapse, seizures, coma, death, jaundice
treatments - hepato-protectant - sAME, UDA, silybin. Glucose supplementation
Pyrethroid poisoning
found in ant powders/old flea products
cats susceptible
CS - ataxia, tremors, disorientation, seizures, dyspnoea, respiratory arrest, hypersalivation, vomiting
diagnosis on exposure/CS
Treatment - general principles, decontamination, intralipid very good
Cleaning procedures
damage through surface contact
CS - oral pain, dysphagia, regurgitation, vomiting
dont do gastric decontamination
Dilute with oral water etc
Ethylene glycol toxicity
metabolised into glycoaldehyde, glycolic acid and oxalic acid.
Glycoaldehyde - neurotoxic
Glycolic acid - severe acidosis
oxalic acid - calcium oxalate crystals in organs
High mortality
CS - v+, lethargy, ataxia followed by tachyarrythmias, tachypnoea, hypocalcaemia then AKI and death
Treatment - medical ethanol/vodka diluted with saline. Dialysis with referral
Warfarin poisoning
inhibits vit K production which stops clotting factors leading to coagulopathy
Diagnosis - prolonged clotting, haemothorax in large bleeds
Treatment - injectible/oral vit K, fresh frozen plasma for clotting factors
raisin/grape toxicity
substance unknown
leads to AKI
treatment - IVFT
Recreational drug toxicity
Cocaine - hyperactive/hyperthermic/V+/ataxia. General treatment
Marijuana - vomiting, ataxia, depression, coma, incontinence. treated generally, intralipid, catheterisation and anxiolytics
Opiates - depression, lethargy, V+, constipation. Treatment - general, reversal - naloxone
Ketamine - ataxia, hallucinations, aggression, cataplexy - treated with general principles and intubation
Lily toxicity
substance not known
cats very sensitive - AKI
dogs - GI signs
Treat as AKI plus decontamination in case of pollen on feet etc
Onion/garlic/leek/chive toxicity
large quantities for toxicity
sulphur containint - haemolysis/heinz body anaemia
CS - V+/D+, tachycardia, tachypnoea, pale MM
treat - general principles + transfusion
Tremorgenic mycotoxins - fungus
Penitrem A - neurotxic
CS - muscle tremors, hyperaesthesia, seizure, coma, death (rare)
Treatment - general principles, methocarbamol for tremors but is off license (diazepam does not work)
Good prognosis but look bad
signs for FB
history - scavenger, acute severe vomiting, abdominal pain/palpable obstruction
diagnosis - plain/contrast radiography, ultrasound, CT/endoscopy
Treat by removal
Treatment of acute gastritis
time, reduced toxin exposure, fluid therapy
anti-emetics
reduce acid damage - highly digestible, low fat/fibre wet/hypoallergenic
helicobacter chronic gastritis
high prevalence in companion animals
try symptomatic meds/diet first
in man treated with - amoxyclav, clarithromycin and PPIs
what antiemetics are available
maropitant
ondansetron
metoclopramide
what drugs reduced acid secretion
PPIs
H2 agonists
antacids
synthetic prostaglandins
sucralfate
Gastric ulceration
end of chronic gastritis
CS - chronic vomiting, haematemesis, malaena
Bloodwork - evidence of GI bleeding
Ultrasound - loss of wall layering, reduced motility, free fluid with perforation
endoscopy - similar to neoplasia, biopsy for definitive
Treatment - surgical for perforation, medical for chronic gastritis
what is a gastrinoma
rare neuroendocrine tumour of the pancreas secreting gastrin
leads to ulceration/erosion along the GIT
Indications for exploratory laparotomy
if diagnosis can only be made by inspection/palpation
if diagnosis needs cytological/histological or culture for diagnosis
Therapeutic indications for ex lap
haemorrhage control
correction of contamination/infection
elimination of pain cause
removal of mass
removal of visceral obstruction
removal of traumatised organs
relief of dystocia
removal of abnormal fluid accumulation
supportive care
common mistake during exlap
failure to make a large enough incision
failure to explore the entire abdominal cavity
failure to take appropriate biopsies
failure to be prepared for the likely diagnosis or diagnoses
failure to approach the intra-operative findings in a logical fashion
what are the 5 regions to check
cranial quadrant
intestinal tract
right paravertebral
left paravertebral
caudal
what fixes the duodenum in place
dueodeno-coelic ligament
what does the duodenal manouvere allow visualisation of
caudal pole of right kidney and right ovarian pedicle
what does the colonic manouvere allow visualisation of
left kidney and left ovarian pedicle
what layer of the linea alba is crucial to close
rectus sheath
what suture pattern is best for the linear alba
continuous to spread tension
why do you have to take care an oesophagostomy tube doesnt sit in the stomach
it allows acid reflux
clinical signs of oesophageal FB
retching
regurgitation
vomiting??
ptyalism
anorexia
restlessness
cervical pain
what drugs can be used to reduce chance of oesophageal stricture after FB removal
H2 antagonists
PPI
sucralfate
analgesia
feed soft food
indications for gastric surgery
placement of gastric feed tube
gastrotomy for FB
gastropexy to stop volvulus
correct GDV
pyloroplasty for outflow disease
partial gastrectomy for tumour resection
Enterotomy for FB removal EXAM
Orthogonal xrays needed for locations
proximal to obstruction is likely to be distended and distal empty
incise through unaffected bowel and milk out the proximal distension
close with single layer - simple continuous, interrupted or inverting. use non-cutting needle and drape omentalise
Problems occuring with linear FB
string/wool anchored somewhere proximal
concertinas the bowel and tries to cut through the mesenteric border - can perforate in multiple locations
must free proximal attachment before removal
points of care for enterectomy
clamps on bowel remaining must be atraumatic
others can be traumatic
ligate mesenteric vessels
cut on diagonal towards mesentery to maintain blood supply
end to end anastomosis with simple continuous
close mesentery
indications for large intestine surgery
colopexy
colotomy
colectomy
subtotal colectomy
colonic torsions
small bowel torsion
differences between cat and dog pancreas
dog pancreatic duct small/absent cat is present
dog accessory pancreatic duct is large in cats it is absent in 80%
where do you biopsy the pancreas
tip of the left limb as most avascular
what does the liver do
metabolic processes
digestion of; fat/triglycerides, protein, carbohydrate/glycogen/cholesterol/vits/mins
waste management
protein metabolism
acute diarrhoea causes
diet - food changes, allergies, intolerance, scavenging. food poisoning/toxins
drugs - antimicrobials/chemo
infections - parvovirus, corona virus, adenovirus, rotavirus. Bacteria - salmonella, campylobacter, e.coli, clostridial species
parasites - helminths, protozoa - giardia/tritrichomonas