Five Types of Snakes throughout the World
1. Colubridae Rear Fixed fangs African boomslang is the only truly dangerous one
2. Elapidae front fixed fangs the poisonous family
3. Hydrophidae Sea Snakes front, fixed fangs Paralysis and myonecrosis
4. Atractaspididae front, mobile fangs
5. Viperidae front, mobile fangs Pit Vipers and True Vipers
CBC, PT/PTT, Fibrin Splits, Fibrinogen, T+C 4 units
Copperhead-often do not need to be treated
Timber Rattlesnake-rocky bluffs or ridges, Cause PLT destruction
Eastern Diamondback-most dangerous in US, dont retreat from humans
Western Diamondback-also will attack humans
Cottonmouth-swims and crawls
Eastern Coral-red on yellow kills a fellow, neurotoxic. Has to chew instead of inject venom
4 Rows of scratches=non-venomous snake
Pseudosnake bite-self-inflicted puncture wounds to get pain meds
Typical snake bite victim: 99% men, 99% white, 40% with tattoo on L forearm
Venom injected SC not IM
snake bite extractors do not work (Annals EM February 2004 Volume 43 Number 2)
Crotalinae of viperidae family: Rattlesnakes, sidewinders, diamondbacks
Agkistrodon: copperheads and cottonmouths
Pit between eye and nostril
Bite is immediately painful
Toxin disrupts coagulation path leading to DIC, shock, and NCPE
Paresthesias, muscle fasiculations, weakness, paralysis, respiratory failure, renal failure
Antivenin for patients with moderate or severe envenomation
best if administered within 6 hrs of bite.
6 vials to start, if initial control, give 2 vials at 6, 12, and 18 hours
If no control (systemic effects, Lab abnormalities, Spread of Local Swelling), give additional 6 vials and repeat until control. Starts to work in 1-2 hours, no pretreatment needed. Antibiotics only if signs of infection. Same crofag dose in peds.
Contraindicated if allergic to papayas.
$800 per vial
timber rattler not included in the antivenin, ? of cross reactivity
test dose has 10% rate of false positive and false negative. Can cause anaphylaxis, most will get serum sickness.
Necrosis, hemolysis, PLT destruction, edema, dry gangrene, early Hypotension (bradykinin), shock, and bleeding diatheses
Eastern and Sonoran coral snakes
Red next to yellow kills a fellow, Red next to black, venom lack. (Only here does the rhyme apply, not Africa)
Block neuromuscular transmission. Ptosis, diplopia, dysphagia, paresthesias and paralysis.
Antivenin for eastern coral, recommended to give before symptoms, as symptoms can be delayed and severe
Never discharge secondary to late morbidity
Neurotoxin, can cause paralysis
If bitten on finger, swelling to the midpalm is minor, the wrist moderate, above is severe
Acute compartment syndrome-muscle injuries not necessarily associated with compartment pressures, so do not perform empirically
Finger dermotomy is recommended. Call hand surgeon.Back to top
Gila monster and Mexican beaded lizardBack to top
Bees, wasps, hornets-remove stinger c back of scalpel blade
Remove bee stings as rapidly as possible regardless of method, no increase in venom in blood by method, definitely increases with time to removal (JB 23, Also Lancet Article)
Fire ants-hemolysis and complement activation
Refer severe sting allergies to allergist for desensitizationBack to top
Shiny black with red or yellow hourglass on rounded abdomen
Only the female has long enough fangs to bite humans
Initially only small sting. 15-30 minutes after the bite, dull crampy pain spreading outwards
Abd and chest get rigid
CNS abnormalities and autonomic dystability
Give tetanus toxoid
Monitor 4 hours
One amp CaGluc Q2-4 hrs
Consider valium or dantrolene
<16 or >65 get antivenin, or life threatening complications
Brown Recluse or Fiddleback
Little brown spider with violin marking on back
Prefer dark, dry places: basements, woodpiles, barns
Venom is tissue destructive. Bite is initially painless. 2-6 hours later, get itching, mild tenderness, and erythema
1-7 days erythematous area is now large necrotic lesion
Systemic effects can occur 24 hours after bite and include: n/v, malaise, hemolysis, DIC, ATN
Vasoconstrictive area around bite then necrosis spreads outwards.
Systemic effects, can get DIC
Local wound care, dT,
Give dapsone 25 to 100 mg PO BID for 2 weeks, make sure not G6PD
Not venomous, but their abdomens are covered with urticating hairs, will cause inflammatory response if they flick them at you. Explorers club ate them and got pharyngeal tingling.Back to top
Worst sequelae is respiratory failure. Venom causes prolonged and excessive firing of nerves.
Antivenin available, but usually supportive care, benzos, and intubation if needed are sufficientBack to top
Tail barbs can penetrate the hulls of boats
Has heat labile toxin containing phosphodiesterase and serotonin causing bradycardia, resp depression, and seizures
Severe pain with a wound that is first dusky then red and hemorrhagic to necrosis
Muscle cramps, syncope, paralysis, seizures. Severe bacterial infection can also result often with Vibrio vulnificans.
Give Pain control, immerse limb in warm water to deactivate toxin, treat for any infections
Myotoxins cause rhabdomyolysis or paralysis
Supportive care and antitoxin
Lionfish: complex venom that causes severe pain, swelling, and tissue loss locally
Stonefish: heat labile toxin. N/V, hypotension, dysrhythmias, syncope, dyspnea, seizures, coma, paralysis. Soak limb in hot water. Irrigate vigorously. Remove any spines in wound, Tetanus proph, Antivenom available, dose based on number of spines.
Weeverfish: most venomous fish in the temperate zone. Causes severe local inflammation with tissue loss and possible gangrene
Contain Nematocysts used to immobilize their prey. Even detached tentacles retain toxicity for months. Venom contains bradykinin, hemolysin, serotonin, histamine, etc.
Localized dermatitis with severe pain and eventual scarring. Systemically, paralysis, CNS changes, seizures, respiratory failure, muscle spasm, coma, and death.
Rinse with seawater or urine, fresh water will cause further discharge of venom
Inactivate with vinegar
Remove tentacles with forceps
Cover nermatocysts with shaving cream or talcum poweder
Shave off with razor blade
are treated by removing the nematocysts without allowing them to discharge. The area should first be washed with sea water; fresh water may cause the nematocysts to discharge. Tentacles should be removed with a gloved hand or forceps. The area should not be rubbed with sand, because this old form of therapy actually makes the condition worse. The remaining nematocysts should be fixed by pouring vinegar over the wound area. Sodium bicarbonate may be used for sea nettle stings. The area should be dusted with talcum powder or covered with shaving cream, and the nematocysts, now adherent to the powder or cream, can be scraped off with a knife. The area should then be washed with sea water, and a steroid cream applied. Most lifeguard stations in areas where coelenterate stings are common have the necessary materials for this regimen. Most EDs have the equipment, but by the time the victim arrives at the hospital the damage may be already done.
Antivenin for chironex (most deadly of jellyfish)
severe local and systemic symptoms after carukia barnes (box jellyfish) sting.
Nonspecific ekg changes with elevated troponin
pain, restlessness, diaphoresis, vomiting, coughing
phentolamine for sympathetic excess
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