Snake Bites Flashcards
What are some examples of venomous snakes that can be found in the US? What is their scientific name? What are they also referred to (due to their anatomy)?
Rattlesnakes, water moccasins (cottonmouths), and copperheads
Family: Viperidae, subfamily: Crotalinae
AKA “Pit vipers”, from their heat sensing pit located behind the nostrils
Where are rattlesnakes found?
Native to and live in all states except for Alaska, Hawaii, and Maine
Where are water moccasins or cottonmouths found?
Southeast-South, Virginia-Texas
Where are copperheads found?
Eastern continental states, Massachusetts-Texas
A majority of snake bites occur in (children/adults) (males/females)
Adult men
~____% of envenomated patients are hospitalized
50%
Ecchymosis and progressive swelling are signs of _________
Local tissue damage
______ reactions, such as nausea, vomiting, abdominal pain, paresthesias, and dizziness, suggest (less/more) severe envenomation
Systemic; more
What are systemic signs from increased vascular permeability following a snake bite?
Tachycardia, tachypnea, and hypotension
Oral paresthesia, unusual taste, fasciculations, altered mental status, seizures are all signs of ______
Neurotoxicity
_________ is the only type of Crotalid bites that can cause neuromuscular weakness with respiratory failure. This reaction can be delated up to ____ hours post-bite.
Mojave rattlesnake; 12
Before the patient arrives at the hospital following a snake bite, the patient should immobilize the injured body part at what level?
Heart level
Snake bite patients (should or should not) use pressure immobilization, tourniquets, incision and oral suction, or mechanical suction devices
should not
T/F If a snake is dead, it can still bite you
True, there may still be an intact bite reflex
T/F Every time a snake bites, there is venom delivered
False, dry bites comprise 25% of all Crotalinae snake bites
T/F Hypotension/altered mental status following a snake bite are rare
True
Why do we order a serum creatine kinase and UA following a snake bite? What are we looking for?
Rhabdomyolysis
T/F You should elevate a snake bite wound
False, keep at level of the heart
Matching: Mild, Moderate, Severe envenomation
A. Edema >12 inches around wound, altered lab values
B. Local pain and edema, normal lab values
C. Petechiae, hypoTN, ecchymosis, abnormal lab values
A. Edema >12 inches around wound, altered lab values –> Moderate
B. Local pain and edema, normal lab values –> Mild
C. Petechiae, hypoTN, ecchymosis, abnormal lab values –> Severe
Is CroFab dosing weight based?
No
If a pt has certain allergies, they should not receive CroFab. What allergies are we particularly concerned about?
Dust mites, papaya, pineapple, and latex
CroFab should be administered at a (fast/slow) rate
Slow
T/F Tetanus prophylaxis is recommended for all snake bite patients
True
CroFab shows a decreased time for return to full function, but overall no significant difference in outcomes ___ months out from injury.
4
Can CroFab be administered to individuals with known allergy to it?
Yes, in serious envenomation cases
T/F CroFab is safe for use in pregnant women and young children
False, due to stabilizing preservatives
Acute reactions to CroFab are often (immunologic/nonimmunologic) in nature, however allergic reactions can be secondary to _____ _____, particularly in those who have been bitten before or who handle snakes
nonimmunologic; venom sensitivity
1st line tx for anaphylaxis is _____. 2nd line?
1st line: Epinephrine
2nd line: H1 Antihistamine, Beta 2 adrenergic agonists, and glucocorticoids
Why is antivenom administration, and not FFP or heparin, the primary tx for Crotalinae-induced coagulopathy?
Because transfused platelets and coagulation factors in FFP are inactivated by Crotalinae venom
Heparin is also ineffective as the thrombin-like substances in the venom are not inhibited by antithrombin III
Snake venom contains a Protein C activator and thrombin-like glycoproteins which form _____ by working like _____ on the fibrinogen molecules. This results in the development of decreased ______, prolonged _____, and decreased _____
fibrin; thrombin; fibrinogen, PT/PTT, platelets
What is the triad of rhabdo presentation? hint: think urine content/color/and lab value)
pigmented granular casts in the urine,
a red to brown color (“iced tea”) of the urine, and a very high total creatine kinase (CK)
What is the initial recommended tx of rhabdo? What electrolyte imbalances should be checked for as well?
IV hydration NS
HYPERkalemia, HYPERphosphatemia, HYPOcalcemia
What is a potential complication of rhabdo?
Acute renal failure
_____ syndrome is a rare but serious complication of a snake bite, with paralysis being a (early/late) finding.
Compartment syndrome; late
What is currently accepted as the best prevention/treatment of compartment syndrome?
CroFab
T/F Pts with compartment syndrome should be immediately taken in for surgery
False, surgical intervention should be avoided if at all possible
A fasciotomy should only be considered when the difference between compartment pressure and diastolic blood pressure is less than ____mm Hg or when clinical symptoms are obvious
30 mmHg
A _____ monitor can be used to evaluate a pt’s compartment pressure, however, if one is not available, what can be used in its place?
Stryker; an 18-gauge needle can be attached to an arterial pressure monitor
If a pt has received anti-venom tx, do they require admission?
Yes
If a pt has mild or no toxicity on initial clinical assessment and normal baseline testing, how long should they be observed for following snake bite?
8-12 hours
If a pt is a child or elderly, has significant comorbidities, or has poor social supports for follow-up, how long should they be observed for following snake bite?
up to 24 hours
Since neurotoxicity may be delayed in asymptomatic patients with suspected Mojave rattlesnake bites, how long should they be observed for following snake bite?
12-24 hours
T/F Most victims of venomous North American snakes do not fully recover
F, they do; death following Crotalinae snake bites is rare
Morbidity/mortality usually associated w/ bites to the ____ or _____
face, UEs
What is the most common loss following a snake bite, in terms of ability?
Loss of ROM
