3-5 vials in 500cc NS & Observe for 24 hours. • This antivenom is no longer being
made. • Remaining antivenom is expired but can still be given if available.
Joseph Heidenreich, MD Department of Emergency Medicine - Temple, TX
800-222-1222
• How many types of venomous snakes are there? • Worldwide: 3000 species of snakes, 15% venomous • USA: 120 native species, but only 20 are venemous • No poisonous snakes in Maine, Alaska or Hawaii!
•So how many people actually die from
snakebites each year compared to other bites?
•45,000 snakebites (8000 envenomations)/year
•About 5-10 deaths/year •Shark attacks result in 2-5 deaths/year •Dogs bites result in about 10-15 deaths/year •Bee stings result in about 120 deaths/year
120 types of snakes; 4 venomous types: 1. 2. 3. 4.
Rattlesnakes (10 species) Copperhead (3 subspecies) Cottonmouth (Water mocassin) Coral snake
Crotalus atrox
Akistrodon contortrix
Pit Vipers Elapidae
Akistrodon piscivorus
Crotalus virudus (Western or Prarie Rattler)
Sistrurus catenatus (Black Rattler)
Agkistrodon contortrix (Copperhead)
Akistrodon Piscivorus (Cotton Mouth or Water Moccasin)
120 types of snakes; 4 venomous types: 1. 2. 3. 4.
Rattlesnakes (10 species) Copperhead (3 subspecies) Cottonmouth (Water mocassin) Coral snake
Micrurus Fulvius Tenere (Coral Snake)
Pit Vipers Elapidae
North
West
Western Diamondback Timber Rattlesnake Copperhead
Western Diamondback Massasauga Prairie Rattlesnake
East
South
Pigmy Rattlesnake Copperhead Cottonmouth Coral Snake
Western Diamondback Copperhead Massasauga Coral Snake
Puff Adder Unknown 37% Copperhead 20% Rattlesnake 18% Nonvenom 15% Cottonmouth 4% Exotic 4% Coral 2%
• Fixed short fangs • Texas venom less potent
than Eastern Coral • Delay of effects up to 12 hours • Venom causes very little pain or swelling • Venom has systemic effects: block NMJ • ptosis, vertigo, paresthesia, fasiculations, slurred speech, dysphagia, increased salivation, muscle weakness, respiratory failure.
• Supportive care (ventilatory support) • Mandatory admission or 12hr observation • Treatment with Coral Snake antivenom • 3-5 vials in 500cc NS & Observe for 24 hours • This antivenom is no longer being made. • Remaining antivenom is expired but can still be given if available.
Red on Black friendly Jack
Red on Yellow kill a fellow
Pit Vipers • Fang marks may be single, double, or multiple • Fangs may break off in wound
• Cytotoxic (local tissue damage, capillary leakage) • Hemotoxic (hemolytic anemia, thrombocytompenia, consumption coagulation, epistaxis, hematemesis) • Neuromuscular (fasiculations, paralysis) • Systemic (vomiting, weakness, chills, abdominal pain, hypotension, tachycardia)
• Most occur May-September • 30% of bites from venomous snakes result in no envenomation (“Dry Bites”) • Usually extremities • Most common victims: Children, Intoxicated adults, Snake handlers
• Envenomation usually subcutaneous • Usually little direct tissue damage • Systemic absorption by lymphatic and venous drainage • Symptoms (even death) due to toxin itself (amount) or allergic reaction to toxin • Intravenous envenomation can result in rapid lifethreatening events • Airway obstruction necessitating tracheal intubation • Bites may become infected
Severe envenomation may initially appear benign and misleading: 1. Within minutes, bite site is painful and swollen 2. Numbness, tingling and other neurological symptoms 3. Edema may progress and involve the whole extremity 4. Ecchymosis, blistering and signs of tissue necrosis Systemic and hematological effects also worsen over time
• Dry bite (No envenomation) local abrasion or bite mark without marked pain or swelling normal vital signs normal coagulation studies normal platelet count • Mild envenomation local pain, swelling, ecchymosis, erythema normal vital signs normal to mildly abnormal coagulation studies platelet count >100,000
• Moderate envenomation local pain; ecchymosis & swelling beyond the bite site near normal vital signs abnormal coagulation studies (doubling of PT and PTT) thrombocytopenia (platelets
