Bites & Envenomations

Question 1

snake envenomation - approach to identifying the snake

Answer 1

*get a description of the snake:
-triangular/wide head, heat-seeking pits, retractable fangs, elliptical pupil, brown = Pit Vipers (copperheads, rattlesnakes, water moccasins)
-red on yellow = Coral Snakes

Question 2

snake envenomation - workup

Answer 2

*CBC w/ diff & platelets
*DIC panel (fibrinogen)
*MONITOR

Question 3

Pit Viper snake envenomation - clinical presentations

Answer 3

1. tissue injury - local necrosis
2. systemic signs/symptoms - distributive shock (hypotension, tachycardia)
3. hematologic problems - disseminated intravascular coagulation (low platelets, low fibrinogen)

Question 4

snake envenomation - management

Answer 4

*mainstay of treatment = antivenin IF they are “sick” (Crotalidae polyvalent immune Fab, aka CroFab); keep the affected limb below the heart

note - compression bands, tourniquets, prophylactic fasciotomy, and resection are ineffective/outdated treatments and are prob the wrong answer

Question 5

black widow spider envenomation - distinguishing features

Answer 5

*big black glossy spider with a red hourglass
*2 innocuous bite sites
*Latin terminology: Latrodectism mactans
*envenomation: Latrodectism

Question 6

black widow spider envenomation - clinical presentations / complications

Answer 6

*severe muscle aches/pains, starting in envenomated extremity and then moving centrally
*hypertension, tachycardia
*venom causes a release of catecholamines
*muscular spasms (can mimic rigid acute abdomen, but no rebound)

Question 7

black widow spider envenomation - management

Answer 7

*SUPPORTIVE/symptomatic care (pain meds, muscle relaxants) = mainstay of treatment
*antivenin
*classic tx with calcium gluconate is largely proven ineffective
*disposition: admit for obs

Question 8

brown recluse spider envenomation - distinguishing features

Answer 8

*brown spider with a violin on its back (“fiddleback”)
*Latin name: Loxosceles reclusa
*envenomation: Loxoscelism

Question 9

brown recluse spider envenomation - clinical presentation / complications

Answer 9

*NECROSIS (red inflammation, white ischemia, blue necrosis that will turn into a black eschar), flulike symptoms
*complication: disseminated intravascular coagulation, rhabdomyolysis

Question 10

brown recluse spider envenomation - management

Answer 10

*treatment: good wound care
-cold compresses slow necrosis
-debridement of obviously necrotic tissue
*dapsone?