Rattlesnake envenomation

Offerman SR, Bush SP, Moynihan JA, Clark RF. Cro-taline Fab antivenom for the treatment of children with rattlesnake envenomation. Pediatrics 2002 110(5) 968-71. 

Bond GR and Burkhart KK (1997) Thryombocytopenia following timber rattlesnake envenomation. Annals of Emergency Medicine 310 40—44. 

McKinney PE Out-of-hospital and interhospital management of crotaline snakebite. Ann Emerg Med 2001 37(2) 168-174. [PMID 11174235] (Review of prehospital and interhospital care.) Ruha AM et al Initial postmarketing experience with crotalidae polyvalent immune Fab for treatment of rattlesnake envenomation. Ann Emerg Med 2002 39(6) 609-615. [PMID ... 

A. Severe pain associated with black widow spider envenomation, rattlesnake envenomation, or other bites or stings. 

Chizar D. Walters A., Urbaniak J., Smith H., et al. (1999). Discrimination between envenomed and non-envenomed prey by W. Diamond-backed rattlesnakes (C. atrox). Copeia 3, 640-648. 

Two phenomena of reptilian prey searching are well investigated responses of various snakes to the odors of invertebrates, and rattlesnakes trailing of envenomated small mammals. 

The rattlesnake C. viridis searches for the particular odor it had experienced when striking the prey. In one experiment, snakes were induced to strike perfume-treated mice. Then they were exposed to perfumed, but non-envenomated, carcasses. The snakes preferred a carcass with the same odor as the originally struck mouse. In a second experiment, snakes preferred the carcasses of mice on the same diet as the ones they had struck. Thus rattlesnakes form a... 

Chiszar, D., Radcliff, C. W., Scudder, R. M., and Duvall, D. (1983). Strike-induced chemosensory searching by rattlesnakes the role of envenomation-related chemical cues in the post-strike environment. In Chemical Signals in Vertebrates vol. 3, ed. D.Miiller-Schwarze and R. M. Silverstein, pp. 1-24. New York Plenum. 

Smith, T. L. and Kardong, K. V. (2000). Absence of polarity perception by rattlesnakes of envenomated prey trails. Journal of Herpetology 34,621-624. 

Snake bite (pit vipers) Antivenin (Crotalidae) polyvalent, equine The entire dose should be given within 4 hours after the bite by the IV or IM route (1 vial = 10 mL) Minimal envenomation 2-4 vials Moderate envenomation 5-9 vials Severe envenomation 10-15 vials Additional doses may be required. Neutralizes the venom of rattlesnakes, copperheads, cottonmouths, water moccasins, and tropical and Asiatic crotalids. Serum sickness occurs in almost all patients who receive > 7 vials. 

Initial pain at the site of the bite may be followed with a metallic sensation in the mouth. Victims may become weak, and experience nausea, diarrhea, diaphoresis, and chills. Edema may begin around the bite area or may be delayed. Observation of the site for edema is a clue as to whether or not a dry bite has occurred that is, that no venom was injected into the site. Envenomation is most serious if venom is injected directly into joints, muscles, or veins. Hemorrhagic blisters and tissue destruction are possible. Neurotoxicity from rattlesnakes (but generally not from cottonmouths or copperheads) may be manifested as fasciculations, which are fine continuous contractions. In some cases, systemic neurotoxicity may involve respiratory failure. In the most serious cases, massive envenomation may lead to serious bleeding, hypotension, shock, multiple organ failure, and a high incidence of mortality. 

F. Snakebite The most common dangerous snake in the USA is the rattlesnake. Although snakebites are common (several thousand per year in the USA), severe envenomation is infrequent. 

Only about 20% of rattlesnake bites involve significant envenomation. Incision, suction, and tourniquets are usually more damaging than helpful. Ice packs are contraindicated. Serious envenomation causes primarily local tissue damage. Antivenin is by far the most effective therapy for serious envenomation. The answer is (D). 

Of the 14 families of snakes, 5 are poisonous (Table 11-54). The annual incidence of snakebite in the United States is three to four bites per 100,000 population. Clinically significant morbidity occurs in less than 60%, and only a few deaths are reported each year. Rattlesnake bite is the most common snake envenomation in the United States, and the victim is often a young, intoxicated male who was teasing or trying to capture the snake. Snakes strike accurately to about one-third their body length, with a maximum striking distance of a few feet. 

Mojave rattlesnake (Crotalus scutulatus) bites deserve special consideration and caution, because neurologic signs and symptoms of envenomation may be delayed and there is often little swelling or evidence of tissue damage. The onset of muscle weakness, ptosis, and respiratory arrest may occur several hours after envenomation. Facial and laryngeal edema have also been reported. 

Consequently, the purpose of our experiments was to see if blood alone carried chemical cues used during poststrike trailing by the rattlesnake to relocate its envenomated prey. 

Second, envenomation does produce a chemical cue that is formed quickly after the strike and immediately secreted fi om the rodent into the environment to produce an odor trail followed poststrike by the rattlesnake (Chiszar et al., 1992b Kardong, 2001). Poststrike, rattlesnakes can follow an odor trail produced by an unstruck mouse (Treatment 2). However, the poststrike trailing success of rattlesnakes significantly improves if provided with the odor trail of a struck mouse (Treatment 1 compared to Treatment 2). Whatever this strike-induced odor cue might be, it is not carried in the blood to surface sites on the rodent for release to the environment. 

Chiszar, D, Walters, A, Urbaniak, J., Smith, H. M., and Mackessy, S. P., 1999b, Discrimination between envenomated and nonenvenomated prey by Western diamondback rattlesnakes (Crotalus atrox). Chemosensory consequences of venom, Copeia 1999 640-648. 

Relocation of the envenomated prey is crucial to the survival of the snake. Therefore, multiple cues could be used by the rattlesnake during relocation to insure... 

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