Immediate removal of extractor is recommended.
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Biomedical subjects
Publications and source records attributed to S P Bush.
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Five episodes of envenomation by centipedes in 2 patients are reported. These arthropods are fast-moving, frightening in appearance to some, and may display aggressive behavior. However, stings from these centipedes, like most found worldwide, caused no serious morbidity or mortality. Common effects included intense local pain, erythema, induration, and necrosis, as well as mild constitutional symptoms. All resolved without sequelae. Treatment included pain control, wound care, and tetanus immunization.
Four cases of envenomation by green lynx spiders (Peucetia viridans) are reported. Despite the unusual appearance and occasional aggressive behavior of this spider, envenomation caused only local pain, pruritus, erythema, and induration. No local necrosis or systemic symptoms occurred. Treatment included tetanus immunization, wound care, and symptomatic therapy.
OBJECTIVE: To test the hypothesis that rattlesnake venom-induced thrombocytopenia would improve following Antivenin (Crotalidae) Polyvalent administration, and that the degree of platelet increase would correlate with the dosage of antivenom. METHODS: The authors conducted a retrospective review of all patients admitted for rattlesnake envenomation at two southern California hospitals between 1980 and 1998. Patients were included if platelet count was less than 150 x 10(9)/L following a rattlesnake bite. Patients were excluded if they received platelet transfusion. The relationship between Antivenin (Crotalidae) Polyvalent administration and venom-induced thrombocytopenia was evaluated by linear regression and paired t-test. RESULTS: The authors identified 103 cases of rattlesnake envenomation. Seventeen cases met inclusion criteria for thrombocytopenia. Two patients were excluded because they received platelet transfusions. One additional patient was excluded from paired t-test only because no antivenom was given. Thrombocytopenia usually improved between presentation and discharge (mean difference, 44 x 10(9)/L), although complete resolution was often not achieved. A statistically significant partial improvement in platelet counts immediately after antivenom administration was observed in a subset of patients with severe thrombocytopenia (platelet count <100 x 10(9)/L) (mean difference, 64 x 10(9)/L). Using regression analysis, the authors did not detect a linear relationship between the amount of Antivenin (Crotalidae) Polyvalent administered and the degree of improvement. CONCLUSIONS: Although rattlesnake venom-induced thrombocytopenia usually improves immediately after Antivenin (Crotalidae) Polyvalent administration and by the time of discharge, the degree of improvement is frequently incomplete and of uncertain clinical significance in the absence of life-threatening bleeding. The authors found no correlation between the degree of improvement and the dosage of Antivenin (Crotalidae) Polyvalent.
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OBJECTIVES: To determine if a commercially available negative-pressure venom extraction device (Extractor) reduces local tissue injury after artificial rattlesnake envenomation in a porcine model. METHODS: We prospectively studied 10 pigs using a crossover design. After the pigs were anesthetized, 25 mg Crotalus atrox venom was injected obliquely with a 22-gauge needle 7 mm deep into subcutaneous tissues proximal to the ventral hind hoof. Pigs were randomized to receive either the Extractor (applied 3 minutes following envenomation and left in place for 30 minutes) or no Extractor. The protocol was repeated 14 days later by using the alternate treatment group and opposite hind leg for each animal. We measured leg circumference at standardized locations on the hoof, foreleg, and thigh at baseline and then 1, 2, 3, 4, 5, 6, 24, 48, 72, and 96 hours following venom injection. Maximal changes in circumference at 6 hours were compared using the paired t test. Minimum residual swelling at up to 96 hours was similarly compared. RESULTS: Maximal 6-hour swelling was similar with and without the Extractor: the hoof difference with the Extractor was -0.1% (95% CI = -3.4% to 3.2%, P = .95), foreleg difference was 0.3% (95% CI = -4.1% to 4.7%, P = .88), and thigh difference was -2.8% (95% CI = -10.0% to 4.4%, P = .40). Minimum residual swelling at up to 96 hours was also similar with and without the Extractor: hoof difference with the Extractor was 1.2% (95% CI = -5.6% to 8.0%, P = .70), foreleg difference was 0.6% (95% CI = -3.7% to 4.9%, P = .76), and thigh difference was 0.3% (95% CI = -2.4% to 3.0%, P = .81). A circular lesion identical in size and shape to the Extractor suction cup, which later necrosed and resulted in tissue loss, developed where the device had been applied in 2 animals. No such lesions occurred in legs not treated with the Extractor. CONCLUSION: No benefit was demonstrated from Extractor use for artificial rattlesnake envenomation in our animal study. The skin necrosis noted in 2 Extractor-treated extremities suggests that an injury pattern may be associated with the device.
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Mojave rattlesnake (Crotalus scutulatus scutulatus) identification has important diagnostic and therapeutic implications. Envenomation by certain populations of Mojave rattlesnakes may cause a different clinical presentation than that caused by other rattlesnakes. Specifically, Mojave rattlesnake envenomation may cause fewer local effects and more neurologic effects (including respiratory difficulty) than are typically seen after bites from other types of rattlesnake. Thus, it is useful for clinicians to distinguish the Mojave rattlesnake from other rattlesnakes in order to prevent underestimation of severe envenomation because of the lack of local tissue injury. Patients suspected to have been bitten by Mojave rattlesnakes may need more aggressive treatment with antivenin as well as more intensive supportive care. In addition, patients suspected to have been bitten by Mojave rattlesnakes should be closely monitored for an extended observation period, as venom effects may be delayed or prolonged. Mojave rattlesnakes may be particularly difficult to distinguish from Western Diamondback rattlesnakes (Crotalus atrox) because of their similarity in appearance and overlapping ranges. The purpose of this report is to provide clinicians with key characteristics which may assist in distinguishing Mojave rattlesnakes from Western Diamondback and other rattlesnakes.
A 67-year-old woman presented to a community emergency department in Orange County, CA, after she was stung by a scorpion identified as Centruroides limbatus from Central America. She developed local pain and systemic symptoms, including parasthesias, flushing, hypertension, and wheezing. Envenomation by this genus of scorpion has not previously been reported in Orange County. Scorpions have been reported to be accidentally transported to areas where they are not indigenous, and patients may present anywhere with envenomation by dangerous scorpion species. Physicians should recognize general identifying characteristics of dangerous scorpions and serious signs of envenomation. Almost all dangerous genera of scorpions (including Centruroides sp.) are in the family Buthidae, which can be identified by a triangular sternal plate. Severe systemic signs of envenomation by Centruroides sp. may include respiratory difficulty, somatic neuromuscular dysfunction, and cranial nerve dysfunction. Patients stung by dangerous scorpions may require airway support, extended observation, antivenin, and avoidance of respiratory depressive medications.
An 18-year-old man was bitten on the hand by a snake he believed to be a Southern Pacific rattlesnake (Crotalus viridis helleri). Within minutes he developed generalized weakness, difficulty breathing, diplopia, dysphagia, and dysphonia. Neurological examination revealed ptosis and decreased motor strength. These symptoms partially improved after administration of Antivenin (Crotalidae) Polyvalent, but the patient continued to have difficulty walking for several days due to weakness. In addition to neurological symptoms, the patient also experienced pain immediately after the bite occurred and rapid swelling of the entire extremity, which extended beyond the shoulder. He complained of a metallic taste in his mouth and developed intense muscle fasciculations of the face, tongue, and upper extremities, which lasted for 2 days and did not improve with antivenin treatment. He exhibited laboratory evidence of coagulopathy and rhabdomyolysis. Although neurotoxins are known to occur in the venom of certain populations of rattlesnakes, only a few clinical reports describing severe neurological symptoms appear in the literature. To our knowledge, this is the first reported case of neurotoxicity associated with a suspected Southern Pacific rattlesnake envenomation.
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A 7-year-old boy presented to the emergency department with severe hypotension and lethargy after a rattlesnake bite. He developed anaphylaxis to antivenom and required intubation, epinephrine, antihistamines, and steroids. Severe rhabdomyolysis and myoglobinuric kidney failure developed over 24 hours, with a peak creatine phosphokinase level of 214,500 units/L. Severe hypocalcemic tetany was treated with replacement therapy. Local wound swelling was never severe and the patient had no coagulopathies. Marked motor weakness improved with antivenom administration. Because of the myotoxic and neurologic effects in the absence of fibrinogenolysis/thrombocytopenia and minimal tissue signs, as well as the similarity to a previously reported case from our area, the envenomation was most likely caused by a Mojave rattlesnake.