Dose Of Antivenin Research Articles

Snake, Spider, and Scorpion Envenomation in North America

Snake, Spider, and Scorpion Envenomation in North America

Snake, spider, and scorpion envenomation in North America.

1. G. Randall Bond, MD* 1. 2. *Associate Professor, Departments of Emergency Medicine and Pediatrics, Medical Director, Blue Ridge Poison Center, University of Virginia, Charlottesville, VA. After completing this article, readers should be able to: 1. Describe which measures for snakebite are harmful and should be avoided. 2. List the signs, symptoms, and findings that indicate a more significant envenomation and the need for intervention with antivenin. 3. Explain when a fasciotomy should be performed and when surgical consultation is necessary. 4. Describe the cornerstone of treatment for black widow spider envenomation. 5. Describe the treatment of brown recluse spider envenomation. In North America, approximately 2,500 children experience a poisonous snakebite each year. More than 95% of these are from pit vipers (family Crotalidae ), including rattlesnakes, moccasins, cotton mouths, and copperheads. Because children have smaller limbs and less subcutaneous tissue and they receive a larger dose of venom per kilogram, their clinical course often is more severe than that of adults. Fortunately, death is rare. ### SIGNS AND SYMPTOMS Pit vipers have no legs and no teeth for mastication. Their venom contains a variety of toxins to halt and kill their prey quickly and to begin the process of digestion from within. Specific components cause direct tissue injury, capillary leakage, coagulopathy, and neurotoxicity. Bites usually cause significant pain from the moment of envenomation. Swelling occurs at the site and progresses at a variable rate, depending on the amount and potency of the venom injected. Local areas may become extremely swollen and tense, and ecchymosis may be noted. Vascular compromise can occur, particularly of the digits. In time, fluid-filled or hemorrhagic bullae may form at the site of the bite, and eventually an area of necrosis may become apparent. Frequently, the first sign of systemic envenomation is tender regional lymph nodes. Other signs include nausea, a metallic taste in the mouth, muscle fasciculations, bleeding from intravenous puncture sites, and less commonly, hypotension and shock. Ptosis and weakness are common following envenomation by some subspecies of the …

Crotalidae envenomation in children.

Poisonous snakebites cause a severe envenomation syndrome in children, yet treatment remains controversial. Sixty-seven patients were treated for poisonous snakebites at our institution between 1975 and 1990; 18 were children < or = 12 years old. There were 13 rattlesnake bites, 4 copperhead bites, and 1 unidentified bite. Initial management included intravenous fluids and antibiotic administration, laboratory studies, tetanus prophylaxis, affected limb elevation, and a limited excision of the bite site in the emergency room. Antivenin was administered only if signs of systemic involvement such as shock, coagulopathy, gastrointestinal cramping, or neurological involvement were present. Children developed systemic involvement 72% of the time, 9 children (50%) developed coagulopathy. Consequently, 11 (61%) children received antivenin. The dose of antivenin they received was 3.2 ml/kg and the children tolerated it well with only 36% of them demonstrating adverse reactions to the antivenin. Clinically, the pediatric patients demonstrated signs and symptoms of a fulminant envenomation syndrome (8 days, average hospital stay), yet, they had a good eventual outcome. Only 11% of children reported long-term morbidity. No deaths occurred and 100% of patients were able to return to full preinjury activities. We conclude that Crotalidae envenomation in children is a serious disease and warrants hospitalization, early surgical involvement, and frequent use of antivenin.

Treatment of Snakebite

To the Editor.— The publication of the article on treatment of pit viper bites has been brought to my attention. I regret the publication of this article without conflicting opinions of others. Here in Florida, a recent survey indicates close to 600 venomous snake bites each year are treated in emergency departments. In the last three years we have averaged one death per year. It is highly probable, therefore, that the mortality is not affected anyway by the method of treatment. The only question, therefore, is the extent of morbidity and disability resulting from the bite and subsequent treatment. The best information available to this office indicates that about half of the venomous bites in the state are treated solely or primarily with antivenin. Depending on the location and reaction, massive doses of antivenin may be given, sometimes 10 to 12 vials. The results that have been reported have been