Envenomation Flashcards Preview

2018 VU Trauma > Envenomation > Flashcards

Flashcards in Envenomation Deck (39)
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1
Q

What routes can toxins take on the body?

A
  • Intravenous
  • Inhalation
  • Intraperitoneal
  • Subcutaneous
  • Intramuscular
  • Intradermal
  • Oral
2
Q

What types of toxins are there?

A
  • Neurotoxins
  • Postsynaptic toxins
  • Myotoxins
  • Locally acting toxins
  • Haemotoxins
3
Q

What are the 3 basic workings of neuro toxins?

A
  • Block/prevent nerve conduction
  • Spontaneous action potentials
  • Abnormalities of acetylcholine release – pre-synaptic toxins
4
Q

What are some effects of neurotoxins?

A
  • Neuromuscular paralysis associated with respiratory failure
5
Q

How do the toxins found in blue ring octopus and puffer/toad fish work on the body system?

A
  • TTX released prevents the action potential propagation by Na+ channel blockade.
6
Q

What effects are seen from the Sydney funnel web spider?

A
  • The Atraxotoxin will cause
    o Gross muscle twitching
    o Catecholamine release and glandular hypersecretion
     The above is due to the development of spontaneous action potentials that are uncontrollable. These occur throughout the skeletal and autonomic nerves.
7
Q

What spider is the alpha-latrotoxin seen in?

A
  • The red back spider
8
Q

What does the alpha-latrotoxin do to the body?

A
  • Depletion of the pre-synaptic vesicles

- The above results in patchy muscle paralysis and catecholamine release.

9
Q

What type of toxin is seen in all Australian snakes?

A
  • Postsynaptic toxins
  • They will block post-synaptic acetylcholine receptors causing paralysis
  • Has rapid onset – but also rapid relief if anti-venom is administered.
10
Q

What are the effects of Myotoxins?

A
  • They affect the muscles
  • May cause rhabdomyolysis and potential for renal failure
  • Common in Australian snakes
11
Q

How are locally acting toxins seen in snake venom affect the body?

A
-	Result in the following
o	Local pain
o	Oedema
o	Necrosis
o	Possible headaches
o	Systemic myalgia – pain in muscle/group of muscle
12
Q

How are locally acting toxins seen in marine venoms affect the body?

A
  • Sever pain
  • Ischemia
  • Cyanosis – blueish apperance
  • Necrosis
13
Q

What is necrotising arachnidism?

A
  • The area around the bite becomes oedematous and necrotic over a couple days.
  • Seen in the white tail spider.
14
Q

What is seen in Haemotoxins?

A
  • Pro-coagulation
  • Anti-coagulant activity
  • Haemolysis
  • Platelet effects
15
Q

What is the process of envenomation?

A
  • Snake strike occurs and venom is deposited in the form of an avascular liquid or blobs.
  • Depending on the venom type – pain/tissue damage will occur at site of the bite.
  • For the venom to move centrally It must enter through the following:
    o Blood vessels
    o Lymphatic system
    o Tissue planes.
  • Regional lymph nodes become enlarged and tender after a venomous bite.
16
Q

What are you more likely to die from in a snake bite? Anaphylaxis or the venom?

A
  • Anaphylaxis
17
Q

What venomous effects does the Australian brown snake have?

A
  • Pro-coagulation, Nephrotoxicity, Paralysis, Haemolysis
18
Q

What venomous effects does the Australian Tiger snake have?

A
  • Rhabdomyolysis, Pro-coagulation, paralysis, Haemolysis
19
Q

What venomous effects does the Australian Red bellied black snake have?

A
  • Rhabdomyolysis, pro-coagulation, paralysis
20
Q

What venomous effects does the Australian copperhead snake have?

A
  • Rhabdomyolysis, Anticoagulation, Paralysis
21
Q

What are common signs of a snake bite wound?

A
  • One ore two small puncture wounds approx. 1cm apart.
  • Bleeding and venom residue – will appear as milky fluid.
  • Pain, swelling and redness around bite site.
  • Bite site may not be visible to naked eye or will present as a scratch.
22
Q

How will a Pt present with a snake bite?

A
  • N + V
  • Difficulty in breathing
  • ACS, headache, visual disturbances
  • Loss of consciousness
  • Chest and abdominal pain
  • Paralysis and convulsions
  • Acute renal failure
  • Rhabdomyolysis
  • Ptosis – dropping of upper eyelid.
23
Q

S&S <1-hour post snake bite if left untreated?

A
  • Headache
  • N+V
  • Abdo pain
  • Hypotension with confusion
  • LOC
  • Regional inflammation
  • Tender lymph nodes
24
Q

S&S 1-3 hours post snake bite if left untreated?

A
  • Cranial nerve paralysis
  • Haemorrhage from mucosal surfaces / puncture site
  • Tachycardia / hypotension
  • Tachypnoea / shallow tidal volume
25
Q

S&S >3 hours post snake bite if left untreated?

A
  • Paresis/paralysis of truncal and limb muscles
  • Paresis/paralysis of respiratory muscle
  • Peripheral circulatory failure
  • Hypoxaemia/cyanosis
  • Rhabdomyolysis
  • Dark urine
26
Q

Do you wash the site of a snake bite?

A
  • No

- The venom @ site can be absorbed into bandage and be used to match the venom

27
Q

What should be done if bite site is not located in an area were pressure bandaging will be effective?

A
  • Sit Pt as still as possible
28
Q

Indications for PIT?

A
  • All Australian snake species (including sea)
  • Funnel web spider
  • Blue ringed octopus
  • Cone fish
29
Q

Contras for PIT?

A
  • Any other spider bites
  • Jelly fish stings
  • Stone fish and other fish stings
  • Scorpion, centipede and beetle bites
30
Q

What pressure do you want to do a PIT?

A
  • Same as a sprained ankle
31
Q

What treatment should be used for a redback spider bite?

A
  • Apply cold pack for pain relief.
32
Q

Why do you not apply pressure to a redback spider bite?

A
  • Its venom is tissue necrotic and will cause severe necrosis of surrounding tissue if held in place under pressure.
33
Q

What will the venom of the Red back spider do to the victim?

A
  • It is a multi-component venom

- Will cause stimulation of neural synapses – wide ranging effects

34
Q

What does the Atraxotoxin from them Sydney funnel web spider do to the body?

A
  • Will cause an autonomic storm with SNS or PNS dominance or both.
  • May cause severer life threat within 10 minutes
35
Q

What symptoms will a bite from the SFW cause?

A
  • Gross muscle twitching
  • Catecholamine release
  • Glandular hypersecretion due to development of uncontrollable spontaneous action potential and autonomic nerves.
  • Tachycardia/hypertension
  • Anxiety
  • Abdo pain
  • Mouth tingling
  • Breathing difficulty
  • ↓ GCS = unconsciousness
36
Q

What is the treatment for the SFW spider?

A
  • PIT bandage
  • Atropine can be sued to reverse cholinergic symptoms
  • Anti- venom – hospital
37
Q

What does the TTX toxin found in blue ringed octopus do?

A
  • Blockade of nerve conduction

- Prevents action potential propagation by Na+ channel blockade leading to paralysis

38
Q

S&S of Blue Ringed Octopus bite?

A
  • Painless bite
  • Numbness in lips and tongue
  • Dyspnoea resulting in cessation of breathing
39
Q

Treatment of a blue ringed octopus?

A
  • PIT bandage

- Tx to hospital