Venomous Animal Injuries

Question 1

How can you differentiate an American coral snake from a king snake, and which one is deadly?

Answer 1

Coral snake: Red next to yellow kills a fellow

King snake: Red next to black, venom lacked

Coral snakes are deadly

Question 2

How do you differentiate a venomous from non-venomous snake

Answer 2

Venomous: triangular head with pointed nose, fangs, pits between eyes and nose
elliptical pupils
caudal plates arranged in a single row

Non venomousL round head, no fangs, no pits, round pupil and double row of caudal plates

Question 3

Outline your first-aid and ED management of a snake envenomation.

Answer 3

First-aid

• Remove any constricting jewelry or clothes
• Minimize spread of venom: calm the patient, immobilize the bitten area
• NPO
• Compression: constricting band proximal to bite (collapse lymphatics and superficial veins) NOT a tourniquet
• Identify snake
• Cardiac monitoring, IV access, fluids
• DON’T: tourniquet, suction, incise, ice submerge wound

ED mgmt

• Supportive care
• Basline coag panel
• Anticipate complications: compartment syndrome, DIC à frequent pulse checks, tcross match blood products
• Wound care
• Antivenom

Question 4

How is severity of pit viper envenomation graded?

Answer 4

Grade 0 (minimal): No evidence of envenomation, snakebite suspected
- LT 1 inch edema, minimal pain, no systemic effects
Grade 1 (minimal): Mild envenomation
- LT 5 inches of edema and erythema, throbbing pain at site, no systemic effects
Grade II (moderate): Edema, pain spreading to trunk, petichiae limited to area of edema
- Nausea, vomiting, mild fever
Grade III (severe): Generalized petichiae, edema involving trunk
- Tachycardia, hypotension
- Evidence of coagulation cascade activation
- Evidence of end organ dysfucntion
Grade IV (very severe): Most often after bite of large rattlesnake
- Local bleb, necrosis, rapidly spreading edema
- Weakness, fasciculations, cramps, seizures

Question 5

Who requires antivenin for a snake bite?

Answer 5

Rattlesnake: Moderate (4-6 vials) to severe reaction (8+ vials)

Coral snake: all
3-5 vials

Question 6

Name 3 adverse effect from anti-venin treatment

Answer 6

1. Anaphylaxis
2. Recurrence of coagulopathy if not re-dosed soon enough
3. Serum sickness:
   a. At 1 week: all who receive horse antivenin, 15% who receive FabAV
   b. Managed with cemitidine, Benadryl, +/- steroids if severe

Question 7

Describe the clinical features of the black widow spider:

Describe the management of a black widow bite.

Answer 7

• Local:
  o Pain and minimal swelling
  o 2 small fang marks at bite site
• Systemic:
  o Dull crampy ache
  o Rigid abdomen although minimally tender
  o Preterm labour, precipitous delivery
  o Bulbar Sx, nausea / vomiting, H/A, facial swelling, weakness
  o ECG: May look like Dig
• Resolution:
  o Pain and cramping for several hours, with resolution over several days
  o Children may have severe reaction, may not survive

- Local:
	o Ice pack to bite site
	o Cleaned with soap and water
- Muscle cramps / spasms:
	o BZD
	o Analgesics
- Antivenin (horse serum):
	o Indications: 
		§ Pregnant, pediatric, elderly
		§ Severe envenomation: Sz, respiratory compromise, uncontrolled HTN
	o Dose of IM epi before administration

Question 8

What type of toxicity does the brown recluse spider venom result in?

Answer 8

• Hemolytic enzymes and vasoconstrictive substance

- Results in severe tissue destruction

Question 9

What is the management of the Brown recluse envenomation?

Answer 9

• Little able to treat the wound locally
• Dapsone 50-200mg/day can prevent local effects of venom, especially if used in first 48hrs
• Analgesics
• Supportive care
• Antivenon only available in Mexico and Brazil

Question 10

How can jellyfish and marine bites be treated by first aid?

Answer 10

• Immersion in hot water (100F) for 30-90min
• Application of vinegar
  Antivenin: stonefish, box jellyfish