Toxic traveler? Latrodectus species envenomation in Michigan with refractory symptoms after antivenin administration.

A 17-year-old male was envenomated on the right forearm by a black widow spider that had presumably traveled in a packaged dishwasher and been shipped from Mexico to Michigan. The patient experienced vomiting and severe pain in his abdomen and chest approximately 30 min after being bitten. He received 6000 units (1 vial) of Latrodectus antivenin intravenously about 7 h after he was envenomated. He did not experience significant improvement in his symptoms after the administration of antivenin and additional antivenin was not given. The patient was hospitalized for 7 days and still was complaining of intermittent episodes of pain in his chest and lower back 3 weeks after envenomation. To avoid prolonged symptomatology and hospitalization, additional Latrodectus antivenin should be given promptly to those individuals whose symptoms are not ameliorated after 1 vial.

Effect of intravenous albumin infusion on brain salicylate concentration.

BACKGROUND: Salicylate poisoning appears to result in death, despite supportive care, once a critical brain salicylate concentration is reached. The binding of salicylate to albumin is saturable; free plasma salicylate concentrations rise disproportionately to total drug levels. Because unbound salicylate distributes into the brain, the authors questioned whether an intravenous (i.v.) infusion of albumin would cause a redistribution of salicylate from the brain back into the plasma, which might allow enough time for hemodialysis to be instituted. OBJECTIVES: To determine if i.v. albumin infusion would lower brain salicylate concentrations through redistribution in a porcine model of acute salicylate poisoning. METHODS: In a randomized controlled trial, 17 swine under anesthesia and controlled ventilation received 400 mg/kg of sodium salicylate i.v. over 15 minutes. At 60 minutes, nine animals received 1.25 g/kg albumin (25% solution) i.v. over 15 minutes, while eight control animals received an equal volume of normal saline (5 mL/kg). Arterial pH was maintained between 7.45 and 7.55. Serial measurements of serum albumin as well as free and total salicylate concentrations were obtained, and urine was collected for measurement of total salicylate excretion. At 180 minutes, animals were killed and brains harvested for measurement of brain salicylate concentrations. RESULTS: Average peak serum total salicylate concentrations of 105.5 and 109 mg/dL were achieved in control and albumin-treated animals, respectively. Albumin infusion was accompanied by statistically significant increases in serum total salicylate concentrations (median from 79.5 to 86.9 mg/dL at 75 minutes), while levels decreased slightly in control animals. Serum free salicylate concentrations decreased slightly in albumin-treated animals, but the difference was not statistically significant. Median brain salicylate concentrations were about 14% lower in the albumin treatment group (17.8 mg/100 g brain) compared with controls (20.5 mg/100 g brain); this approached statistical significance (p = 0.075). Median urinary salicylate excretion was higher in the albumin-treated group (0.83 vs. 0.48 g; p = 0.072), with similar urinary pH and volumes in both groups. CONCLUSIONS: In this animal model of salicylate poisoning, i.v. infusion of 1.25 g/kg albumin was accompanied by a 14% decline in median brain salicylate concentrations, which approached statistical significance.

Safety and efficacy of Crotalidae Polyvalent Immune Fab in pediatric crotaline envenomations.

BACKGROUND: Since it was approved by the Food and Drug Administration in October 2000, Crotalidae Polyvalent Immune Fab (CroFab) has largely replaced previously used crotaline antivenom. CroFab is more specifically tailored for crotalids of North America and is less allergenic than whole immunoglobulin antivenoms. However, premarketing and postmarketing studies have excluded children. OBJECTIVES: To describe the safety and efficacy of CroFab in pediatric crotaline envenomations. METHODS: Using admission and billing records, the authors identified all children 13 years of age and younger treated with CroFab at a pediatric hospital between October 2000 and September 2005. Charts were reviewed by two trained, blinded extractors. Data regarding age, signs of envenomation, laboratory values, total antivenom vials used, total vials used to gain control, transfused blood products, signs of acute allergy to antivenom, and any surgical procedures were abstracted. Data were analyzed using descriptive statistics. RESULTS: Twenty-four patients were identified, and their mean age was 7.3 (range, 1.9-13) years. At presentation, all had swelling, 14 (58%) had a prothrombin time >13 seconds, two (8.3%) had a fibrinogen level <150 mg/dL, and three (12.5%) had platelet counts <150,000/mL. The mean number of total antivenom vials used was 12.3 (range, 4-24). Five patients had resolution of swelling, but platelet counts continued to fall despite antivenom treatment. No patient required blood products, debridement of skin, or fasciotomy. There was only one (4.2%) possible acute allergy to CroFab, and there were no deaths. CONCLUSIONS: In this pediatric series, CroFab appears safe and effective, despite occasional resistant thrombocytopenia.