Snake bites: Difference between revisions
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===Venom=== | ===Venom=== | ||
*Snake venom is a mixture of proteins, peptides, lipids, and metal ions. | *Snake venom is a mixture of proteins, peptides, lipids, and metal ions. | ||
*Many bites can be "dry bites" where | *Many bites can be "dry bites" where no venom is released, about ~1/4 | ||
==Clinical Features== | ==Clinical Features== | ||
*Local injury - punctures marks from fangs not always visible | *Local injury - punctures marks from fangs not always visible; erythema, and edema | ||
*Ooze at fang mark reliable sign of envenomation | *Ooze at fang mark reliable sign of envenomation | ||
*Nausea/vomiting | *[[Nausea/vomiting]] | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
| Line 21: | Line 21: | ||
==Evaluation== | ==Evaluation== | ||
*Clinical Diagnosis | *Clinical Diagnosis | ||
*Evaluate for [[compartment syndrome]] (see below) | |||
*CBC, coags: [[Thrombocytopenia]] and elevated INR can occur in Crotaline envenomations. | |||
==Management== | ==Management== | ||
{{Snake bite local treatment}} | |||
===Supportive care=== | |||
*[[IVF]] and [[pressors]] if needed for [[hypotension]] | |||
*[[pRBCs|Blood]] components rarely needed | |||
*Treatment mainly depends upon the presence of an [[Envenomation|envenomation]] | *Treatment mainly depends upon the presence of an [[Envenomation|envenomation]] | ||
*Indications: | *Indications: | ||
**Progression of local injury - pain, swelling, ecchymosis | **Progression of local injury - pain, swelling, ecchymosis | ||
**Coagulopathy - elevated PT/PTT/INR, low fibrinogen, thrombocytopenia | **[[Coagulopathy]] - elevated PT/PTT/INR, low fibrinogen, thrombocytopenia | ||
**Systemic effects - hypotension, altered mental status, nausea and vomiting, paresthesias | **Systemic effects - [[hypotension]], [[altered mental status]], [[nausea and vomiting]], [[paresthesias]] | ||
*Always provide supportive care and treat local effects of any wounds | *Always provide supportive care and treat local effects of any wounds | ||
*Irrigation of the wound is necessary regardless of the type of snake bite | *Irrigation of the wound is necessary regardless of the type of snake bite | ||
*Debridement and removal of devitalized tissue may be necessary for severe bites | *Debridement and removal of devitalized tissue may be necessary for severe bites | ||
*Evidence does not support use of empiric [[antibiotics]] to prevent secondary infection <ref>Gold B.. Bites of venomous snakes. N Engl J Med. 2002;347(5):347-56.</ref> | |||
*[[Compartment syndrome]] has been documented with crotaline envenomation, but current literature does not support use of fasciotomy. <ref> Cumpston KL. Is there a role for fasciotomy in Crotalinae envenomations in North America? PMID: 21740134 </ref> Treatment should focus on antivenom. | |||
===Antivenom=== | |||
*Snake specific treatments depend upon [[Coral snake]] or [[Crotaline (Pit Vipers)|Pit viper]] envenomations | *Snake specific treatments depend upon [[Coral snake]] or [[Crotaline (Pit Vipers)|Pit viper]] envenomations | ||
==Disposition== | ==Disposition== | ||
*All snake bites with evidence of envenomations should have a period of observation and possible hospitalization | *All snake bites with evidence of envenomations should have a period of observation and possible hospitalization | ||
*Old bites can be assessed | *Old bites can be assessed and discharged if no evidence of envenomation. | ||
==See Also== | ==See Also== | ||
*[[Envenomations, bites and stings]] | |||
*[[Crotaline (Pit Vipers)]] | *[[Crotaline (Pit Vipers)]] | ||
*[[Elapidae (Coral Snakes)]] | *[[Elapidae (Coral Snakes)]] | ||
Latest revision as of 17:08, 17 March 2021
Background
- An average of 5000 native venomous snakebites are reported to US poison centers annually[1]
- In the United States, snake bites can be organized into Crotaline (Pit Vipers) and Elapidae (Coral Snakes)
- Crotalidae family also includes rattlesnakes, Sistrurus and Agkistrodon species (water moccasins and copperheads).[2]
- Risk Factors: "The 'T's" Testosterone, Tequila, Tshirt, Tattoos, Toothless, Teasing, Trailer park, Truck
Venom
- Snake venom is a mixture of proteins, peptides, lipids, and metal ions.
- Many bites can be "dry bites" where no venom is released, about ~1/4
Clinical Features
- Local injury - punctures marks from fangs not always visible; erythema, and edema
- Ooze at fang mark reliable sign of envenomation
- Nausea/vomiting
Differential Diagnosis
Envenomations, bites and stings
- Hymenoptera stings (bees, wasps, ants)
- Mammalian bites
- Closed fist infection (Fight bite)
- Dog bite
- Marine toxins and envenomations
- Toxins (ciguatera, neurotoxic shellfish poisoning, paralytic shellfish poisoning, scombroid, tetrodotoxin
- Stingers (stingray injury)
- Venomous fish (catfish, zebrafish, scorpion fish, stonefish, cone shells, lionfish, sea urchins)
- Nematocysts (coral reef, fire coral, box jellyfish, sea wasp, portuguese man-of-war, sea anemones)
- Phylum porifera (sponges)
- Bites (alligator/crocodile, octopus, shark)
- Scorpion envenomation
- Reptile envenomation
- Spider bites
Evaluation
- Clinical Diagnosis
- Evaluate for compartment syndrome (see below)
- CBC, coags: Thrombocytopenia and elevated INR can occur in Crotaline envenomations.
Management
Local Care
- Do:
- Remove all jewelry
- Mark the leading edge of erythema/edema
- Do not:
- Attempt to suck out the venom
- Place the affected part in cold water
- Use a tourniquet or wrap
- Antivenom is first line treatment for compartment syndrome; fasciotomy is last resort if elevated pressures persist.
Supportive care
- IVF and pressors if needed for hypotension
- Blood components rarely needed
- Treatment mainly depends upon the presence of an envenomation
- Indications:
- Progression of local injury - pain, swelling, ecchymosis
- Coagulopathy - elevated PT/PTT/INR, low fibrinogen, thrombocytopenia
- Systemic effects - hypotension, altered mental status, nausea and vomiting, paresthesias
- Always provide supportive care and treat local effects of any wounds
- Irrigation of the wound is necessary regardless of the type of snake bite
- Debridement and removal of devitalized tissue may be necessary for severe bites
- Evidence does not support use of empiric antibiotics to prevent secondary infection [3]
- Compartment syndrome has been documented with crotaline envenomation, but current literature does not support use of fasciotomy. [4] Treatment should focus on antivenom.
Antivenom
- Snake specific treatments depend upon Coral snake or Pit viper envenomations
Disposition
- All snake bites with evidence of envenomations should have a period of observation and possible hospitalization
- Old bites can be assessed and discharged if no evidence of envenomation.
See Also
References
- ↑ Seifert SA et al. AAPCC database characterization of native U.S. venomous snake exposures, 2001-2005. Clin Toxicol (Phila). 2009;47: 327–335.
- ↑ Goldfranks Toxicology - Envenomations
- ↑ Gold B.. Bites of venomous snakes. N Engl J Med. 2002;347(5):347-56.
- ↑ Cumpston KL. Is there a role for fasciotomy in Crotalinae envenomations in North America? PMID: 21740134