Investigation & Management of Vomiting in Dogs and Cats Flashcards
what is the vomiting reflex
what acts on the vomiting centre (4)
- cerebral cortex
- chemoreceptor trigger zone
- vestibular apparatus
- gastro intestinal tract/peripheral stimuli
what acts on the chemoreceptor trigger zone (5)
- uremia
- DKA
- cardiac glycoside toxicity
- apomorphine
- chemotherapy
what acts of cerebral cortex to cause vomiting (4)
- anxiety
- raised intracranial pressure
- meningitis/encephalitis
- trauma
what acts on the vestibular apparatus to cause vomiting (2)
- motion sickness
- vestibular syndromes
what acts on the gastro intestinal tract/peripheral stimuli to cause vomiting (5)
- chemicals/irritants
- inflammation
- excessive stretch of the GI tract
- peritonitis
- bladder obstruction
how does the GI tract/peripheral stimuli send signals to the vomiting centre
via CN X, IX and sympathetic afferents
what are the receptors in the chemoreceptor trigger zone (6)
- D2 (dopamine)
- 5HT3 (serotonin)
- M1 (cholinergic)
- opioid receptors (μ, κ, δ)
- H1 (histamine(
- NK1
what are the receptors that are on the vestibular appartus (2)
- H1 (histamine)
- M1 (cholinergic)
what receptors are in the GI tract/peripheral stimuli
- 5HT3 (serotonin)
what are the receptors in the vomiting centre (3)
- 5HT1 (serotonin)
- alpha 2-adrenergic
- NK1
how does the vestibular apparatus send signals to the vomiting centre
via CN VIII
how emesis mediated by the vomiting centre (3)
- 5HT4
- Ach (muscarinic)
- motilin receptors
how does the vomiting centre send signal to mediate emesis
via CN X and IX efferents
how do you distinguish the difference between vomiting and regurgitation
which is active and forceful expulsion of gastric and/or duodenal contents, vomiting or regurgitation?
vomiting
which is passive retrograde expulsion of esophageal or gastric contents, vomiting or regurgitation
regurgitation
which is preceded by signs of nausea and retching
vomiting
which occur minutes to hours after eating, vomiting or regurgitation
regurgitation
which occurs minutes to hours after eating, vomiting or regurgitation
vomiting
which has typically undigested or partially digested food or liquid
regurgitation
which has undigested or partially digested food or liquid, often containing bile
vomiting or regurgitation
vomiting
which has forceful abdominal contraction, vomiting or regurgitation
vomiting
how is an episode of acute vomiting treated
often no specific
withholding food for up to 24 hours
bland low fat diets re introduced
small frequent meals
fluids if clinically indicated +/- anti-emetics
what are gastrointestinal disorders that cause acute vomiting (6)
- acute gastritis/enteritis
- dietary indiscretion
- foreign body (gastric or intestinal)
- gastric dilation and volvulus
- mesenteric torsion
- intussusception
what are non GI disorders that cause acute vomiting (7)
- acute pancreatitis
- acute hepatobiliary disease (acute stretch of the liver due to inflammation or increasing levels of bilirubin)
- acute renal failure (uremia, pain or stretch of kidney)
- peritonitis
- acute neurological insult
- endocrine dysfunction (Addison’s disease)
- toxin ingestion/exposure
what are some history questions to ask about vomiting (11)
- recent dietary changes?
- scavenging
- how freq is the vomiting
- is the vomiting unproductive
- undigested food/partially digested/fecal odour
- is there blood or coffee grounds in vomit
- has there been any recent weight loss
- concurrent GI signs
- is the patient on any meds
- is the patient systemically unwell
- appetite
what physical examination abnormalties could be seen with acute vomiting (6)
- are there signs of systemic disease: what’s the patient’s demeanour like, is he/she pyrexic
- is there any indication of liver disease (jaundice)
- is the abdomen painful
- can you palpate any abdominal masses? is there a suggestion of ascites
- assess hydration – CRT, skin tenting
- is your patient hypovolemic
what is the approach to investigation of acute vomiting
what is the initial evaluation of the patient
- CBC and serum biochemistry
- urinanalysis
what can CBC and serum biochemistry evaluate
identification of primary disease processes
what are primary disease processes that can cause vomiting (4)
- acute pancreatitis (inflammatory leukogram, raised lipases, amylase, minor changes in liver profile)
- acute hepatobiliary disease
- acute renal failure
- endocrine dysfunction (DKA)
how can CBC and serum biochem evaluate patient status
- is the patient severely dehydrated
- are there electrolyte disturbances that we need to address
- is there a metabolic acidosis
- do we have changes compatible with sepsis
what can diagnostic imaging evaluate
is it surgical?
- evidence of GDV
- GI foreign body
- obstructive pattern
- GI perforation
- peritonitis
what can abdominal US evaluate
GI tract
- assessment of biliary system
- evaluation of pancreas
- evaluation of repro tract
- US guided aspiration of peritoneal fluid
what are the aims supportive and symptomatic management (4)
- address fluid and electrolyte disturbances caused by vomiting –> IVFT
- reduce frequency/stop vomiting –> anti emetics
- to reduce acid production if there are concerns gastro-duodenal ulceration –> anti ulcer
- improve gastric emptying –> prokinetic drugs
what are the anti emetic drugs (4)
- NK1 pathway inhibitors: maropitant
- anti-dopaminergics: metoclopramide
- serotonin antagonists: ondansetron
- phenothiazines: chlorpromazine
what are the anti ulcer drugs (4)
- histamine (H2) blockers: cimetidine, ranitidine, famotidine
- proton pump inhibitors: omeprazole
- sucralfate
- synthetic prostaglandins: misoprostol
what are the pro kinetic drugs (3)
- metoclopramide (CRI)
- ranitidine
- cisapride
what receptor does maropitant act on
NK1 antagonist
acts on both chemoreceptor trigger zone and vomiting centre
what receptors does metoclopramide act on
D2 antagonist
5HT3 antagonist
where does metoclopramide act on
- chemoreceptor trigger zone
- GI tract/peripheral stimuli
what receptor does odansetron act on
- 5HT3 antagonist
where does odansetron act on
chemoreceptor trigger zone
GI tract/peripheral stimuli
where does misoprotstol act on
PGE1 analog
direct action on parietal cells
inhibits gastric acid secretion
where does rantitidine act on
H2 receptor antagonist prokinetic
at H2 receptors of parietal cells, completely inhibits histamine and reducing gastric acid secretion
where does omeprazole
proton pump inhibitor
binds irreversibly to the secretory surface of parietal cells to the enzyme H+/K+ ATPase where it inhibits the transport H+ ions into the stomach
where does sucralfate act on
local effect in the stomach
may react with HCl to form a paste like complex that preferentially binds to the proteinaceous exudates that are found at ulcer sites
order from least to most potent between ranitidine, famotidine, cimetidine
cimetidine < ranitidine < famotidine
which H2 blocker is licensed in UK
only cimetidine
which has prokinetic acitivity
cimetidine, ranitidine, famotidine
ranitidine
what are systemic causes of chronic vomiting (7)
- chronic pancreatitis
- chronic kidney disease (PUPD?)
- chronic hepatobiliary disease
- hyperthyroidism
- hypoadrenocorticism
- chronic drug/toxin exposure
- neurological disease
what are GI - stomach causes of chronic diseases (7)
- chronic gastritis
- bilious vomiting syndrome
- foreign body
- gastric ulceration
- gastric neoplasia
- pyloric outflow obstruction/stenosis
- motility disorder
what are GI intestinal causes of chronic diseases (7)
- inflammatory bowel disease
- neoplasia
- foreign body
- intussusception
- extra intestinal obstruction
- ulceration
- parasitic
what is the approach to chronic vomiting
what are the primary disease processes that can cause chronic vomiting (3)
- liver dysfunction
- chronic kidney disease
- endocrine dysfunction
what can be seen on rads that may cause chronic vomiting (4)
- chronic FB
- GI neoplasia
- pyloric outflow obstruction
- chronic pancreatopathy
when is endoscopic evaluation used in chronic vomiting patient
when primary disease is suspected
investigation of hematemesis
what causes of chronic vomiting may be seen on endoscopic evaluation (4)
- gastric ulceration
- gastric neoplasia
- chronic gastritis
- duodenal disease (IBD)
what is the etiology of gastric/gastro-duodenal ulceration (6)
- gastritis
- gastric neoplasia (adenocarcinoma, lymphoma, leiomyoma/leiomyosarcoma)
- NSAID-associated ulceration
- metabolic/endocrine disease (renal failure, liver disease, hypoadrenocorticism)
- mast cell disease
- gastrinoma (rare)
what is the most common canine gastric tumour
gastric adenocarcinoma
what breeds are predisposed to gastric adenocarcinoma
belgian shepherds
collies
staffies
how do dogs present with with gastric adenocarcinoma (5)
- anorexia
- vomiting
- weight loss
- hypersalivation
- +/- hematemesis and melena
how do gastric lymphomas present
similar to gastric adenocarcinoma
ulcerative disease
how do you manage gastroduodenal ulcers (3)
- treat underlying disease process
- anti ulcer drugs (4-8 week treatment)
- symptomatic treatment (anti emetic)
how is chronic gastritis diagnosed
according to cellular infiltrate
lympho plasmacytic is most common
mucosal biopsy or gastric biopsy
how is chronic gastritis managed
- diet modification (hypoallergenic diet)
- immunosuppressant medication (prenisolone)
- symptomatic management
when would helicobacter associated gastritis be relevant (3)
if there is
- associated inflammation
- intracellular location
- epithelial changes (necrosis)
how is helicobacter associated gastritis treated
antibiotics and acid lowering drugs
- amoxicillin + metronidazole plus bismuth +/- famotidine
- amoxicillin + metronidazole + omeprazole
- clarithromycin + metronidazole + ranitidine
what is delayed gastric emptying
food in stomach for > 8 hours post ingestion
wjat are potential causes for delayed gastric emptying (7)
- electrolyte disorders
- post anesthetic complication
- local peritonitis
- intramural disease (gastritis, pyloric stenosis)
- extramural compression
- GI foreign body
- dysautonomia (rare)
what can pyloric stenosis cause
can cause delayed gastric emptying
what is shown here
dilation of stomach
accummulation of gas
what are the two types of pyloric stenosis
- congenital
- acquired
what breeds are predisposed to congenital pyloric stenosis
boxers and boston terriers
what does congenital pyloric stensosis involve (muscle, mucosa?)
muscle only
mucosal folds seen in FBD
what does acquired pyloric stensosis involve (muscle, mucosa?)
muscle and mucosa
