Supporting the Poison Case Flashcards
What are the general principles when it comes to toxin case?
- Is there a known toxin?
- How long since exposure?
- What was the route of exposure?
- The initial phone call is an opportunity to give advice and receive information
How can we minimise exposure to inhaled toxins?
Remove from the environment
How can we minimise exposure to dermal contamination?
- wear gloves!
- brush off any powder
- clip the hair
- wash with tepid water & mild detergent (eg w/up liquid)
- 15-20 minutes?
- multiple wash/rinse cycles
- avoid any solvents/neutralising agents (eg white spirit, turpentine)
- think about avoiding hypothermia
How can we minimise ongoing exposure to ocular exposure? What about immediately or in the practice?
- corneal ulceration/injury
- Immediate
- flush with saline or water for 10-15 mins
- At the practice
- continue flushing under sedation if necessary
- fluorescein stain to examine carefully for ulceration
- repeat to monitor?
- lubrication, topical antibiotics, analgesia
- buster collar
- consider referral if alkali injury
How can we minimise ongoing exposure to oral toxins?
- Gastric decontamination
- emesis
- gastric lavage
- administer adsorbents
- Seek advice if the toxin is known
Can we use diluents? If so what?
Milk (~2-6 mls/kg?)
Liquid antacids
What do liquid antacids do and why do we offer small amounts?
- Soothe and coat damaged mucous membranes
- Offer small amounts only
- avoids over distension of stomach
- less likely to vomit
What is diuresis useful for and what can we use?
- renal excreted toxins
- iv fluids +/- mannitol
How commonly are cathartics and laxatives used? What can we use? (3)
RARE
- sorbitol 70% solution 1-3 ml/kg
- lactulose 0.5-1ml/kg
- magnesium sulphate
If we promote elimination what do we need to take care with?
Hydration status
What do we do to treat the consequences of ingesting toxins?
Note:
- Fluids
- Hepatoprotectans
- Haemhorrhage
- Respiratory depression
- Seizures
- Hyperaesthesia
- Tachycardia
- Bradycardia
- Hypothermia
- Hyperthemia
- Nutrition
Fluid therapy
- manage hypoperfusion
- diuresis to enhance elimination of renal excreted toxins
- maintain renal perfusion to protect against nephrotoxins
- “dilution” of toxins that might otherwise be toxic to renal tubules
Hepatoprotectants/antioxidants
- s-adenosylmethionine
- sylibin (milk thistle)
Haemorrhage?
- apply pressure at site of haemorrhage
- are there indications for transfusion
- IV fluids
Respiratory depression?
- oxygen
- intubate and ventilate
Seizures?
- anti-epileptic medication e.g. diazepam, barbiturates
Hyperaesthesia?
- sedatives eg ACP, diazepam
Tachycardia?
- beta-blockers, antidysrhythmics
Bradycardia?
- atropine
Hypothermia?
- external warming
- warm saline enemas/bladder lavage
Hyperthermia?
- ice packs
- muscle relaxants
- NSAIDs (if no concerns about renal and GI perfusion)
Nutrition?
What are the indications to induce emesis? (3)
- Appropriate time window
- ideally <1-2 hours
- can vomiting be induced at home (washing soda crystals)?
- delayed up to 4-6 hours OK in some situations
- slow gastric emptying
- chocolate
- grapes
- ideally <1-2 hours
- Can consider in asymptomatic patients if potential toxicity worrying
- “better safe than sorry?”
- Be aware that evidence for beneficial effects of inducing emesis is lacking
What are the contraindications to induce vomiting? (9)
Even though it might be contraindicated.. Why might it be worth making an animal vomit who ha already vomited? What else could we do?
Vomiting might only empty the stomach by 40-60%. It might still be appropriate to induce further emesis. A lateral radiograph of the abdomen might give an idea of residual gastric volume.
Apomorphine can be given to induce emeis, how can we administer and what are the side effects?
Administration
- 0.02-0.04 mg/kg iv, im or sc
- higher or repeated doses may be required.
- can be given by subconjunctival administration
Side effects include
- sedation
- may become a contraindication to repeat dosing
- bradycardia
- protracted vomiting
- consider fluid therapy
What else used to be given to induce emesis? Causes severe haemhorrhage
Hydrogen Peroxide
What can we use to induce emesis in cats? What is ineffective
α 2 agonists:
- medetomidine 0.01 mg/kg im or sc
- medetomidine 0.01mg/kg and morphine 0.2mg/kg s/c
- xylazine 0.44mg/kg im
- hydroxymorphone 0.05 mg/kg + midazolam 0.2mg/kg sc
- consider side effects such as
- bradycardia
- sedation
Apomorphine is ineffective in cats
What are the indications for a gastric lavage? (4)
- Failure to induce vomiting
- Radiographic or ultrasonographic evidence of residual gastric contents
- Respiratory or CNS depression meaning emesis is contraindicated but recent toxin ingestion
- loss of gag reflex/laryngeal paralysis
- reduced mentation
- Where major concerns that
- dose is close to LD50
- severe clinical signs could occur
What are the contraindication of a gastric lavage? (3)
- Risk of gastric perforation
- Corrosive or caustic substance
- High anaesthetic risk
- cardiovascular collapse?
What is the technique for a gastric lavage?
- Stabilise patient–>GA & cuffed ET tube
- Sternal recumbency
- Orogastric tube:
- large bore
- premeasure from canine tooth to last rib
- mark the site
- lubricate the tube well
- gently pass from oropharynx in to stomach
- ensure appropriate placement
- Lavage with 5-10mls/kg tepid water
- Gently palpate the stomach to avoid overfilling but encourage mixing
- Lower end of orogastric tube in to a bucket at floor level
- Drain by gravity +/- suction
- Repeat the lavage multiple (15-20) times until fluid appears clear
- Administer activated charcoal at this stage if appropriate
- Kink off the tube and withdraw
- Recover in sternal recumbency
- Remove ET tube only when a strong gag reflex is present
- careful observation is essential
What are the functions of absorbents? (3)
- Bind toxin to prevent further absorption from GI tract
- May be more effective than emetic agents used alone
- Must be given swiftly to be helpful
How does activated charcoal work? How do you dose? What are the negatives?
- Provides a large surface area to adhere organic toxins
- eg grape/raisin toxicity and many others
- Dosing:
- mix with water to make a slurry (1g/5mls)
- 0.5-4g/kg orally
- syringe/stomach tube
- Doesn’t adsorb all toxins
- seek advice regarding the specific toxin
- not helpful for ethylene glycol toxicity
- “if in doubt give it”
When is Multiple dose activated charcoal (MDAC) indicated?
How do you dose?
- Indicated when there is
- enterohepatic circulation
- eg theobromine toxicity, cholecalciferol
- ingestion of an extended release drug
- potential for “GI dialysis”
- absorbed toxins are drawn out of systemic circulation along a concentration gradient back in to the GI tract
- Loading dose 1-5g/kg as before
- Repeat dose every 4-6 hours for 24-72 hrs
What are the problems with activated charcoal? (5)
- Not always easy to give
- risk of aspiration pneumonia
- Very messy
- Administration in food
- increases palatability and ease of dosing
- ??reduced efficacy??
- Risk of aggravating fluid and electrolyte imbalance?
- Avoid if endoscopy is imminent….
Discuss the use of an antidote…
- Aim is to prevent, reverse or reduce effect of a toxin
- May not be available
- May be cost prohibitive
- Consider if an antidote might cause adverse effects
What is the anti-dote or:
A) Snake bite?
B) Paracetamol?
C) NSAIDs?
D) Cholecalciferol/vitD analogues
A) Anti venom
B) N-acetyl cysteine
C) H2 antagonists
D) Pamidronate/calcitonin
What is the anti-dote for:
A) Opioid?
B) Ethylene glycol?
C) Anticoagulant rodenticide?
D) Permethrin?
A) Naloxone
B) Ethanol
C) Vitamin K1
D) Methocarbamol
How common is IV lipid emulsion used in animals?
Increasing awareness of this as a simple, easy and relatively cheap treatment
•shortens duration and severity of clinical signs
What is the mechanism of action of IV lipid emulsion?
- Mechanism of action unclear
- lipid sink mechanism
- eg makes toxin unavailable to act on target receptors
- metabolic effect
- eg reduced cardiotoxic effects by providing an energy source
What are IV lipid emulsion suitable for?
Lipophilic compounds with short to moderate t1/2
- permethrin
- macrocyclic lactones (ivermectin, moxidectin)
- baclofen
What are the adverse effects of IV lipid emulsions? (4)
- pancreatitis
- pain at site of extravasation
- potential to trap useful drugs eg anticonvulsants?
- hypersensitivity reactions?
Where can you go for info about toxins and treatments.. (2)
VPIS
iCatCare information
On the inital phone call.. what ifo do we need to get?
- How will the owners feel?
- ask for a contact number
- Information about the pet
- species
- breed
- age
- sex
- weight
- medical history
- any current medication
- Details of the poison
- full name (from the packaging)
- concentration of active ingredient
- manufacturer’s name
- other composition (eg solvents)
- presentation and packaging
- tablets/capsules
- bottles or boxes
- if suspected toxin is a plant…
- seeds?
- berries?
- leaves?
- how much of the toxin is left
- Details of the incident
- what happened?
- route of exposure
- time since exposure
- duration of exposure
- how many animals might be involved?
- Are there any clinical signs?
What advice do we give on the inital phonecall with regard to the toxin ingestion?
- remove pet from source of poison and isolate
- prevent access to any vomit which might contain poison
- take care and avoid contamination of owners
- bring sample of poison and packaging to the practice along with the pet if any concerns
- “better safe than sorry”
