Search

Study Objective: The Meixner test has been suggested to identify the presence of alpha-amanitin, one of the toxic compounds in Amanita mushrooms. We attempted to determine the detection limit of the Meixner test for alpha-amanitin and to determine the percentage of positive sample interpretation compared with other mushroom indole compounds., Methods: This was a 2-part in vitro experiment. In part 1, we applied the Meixner test to a series of dilutions of alpha-amanitin (0 microg, 0.8 microg, 1.0 microg, 2.0 microg, and 4.0 microg) on telephone book paper, which were then presented to 5 blinded emergency physicians. We sought to determine the lowest amount of alpha-amanitin that was universally recognized as positive by the physicians (the detection limit). In the second part, 5 emergency physicians were presented simultaneously with 10 Meixner processed samples, including the mushroom indole compounds alpha-amanitin (2 microg and 10 microg), psilocin (20 microL and 60 microL of mushroom extract), 5-hydroxytryptamine (100 microg and 200 microg), and 5-methoxy-N,N-dimethyltryptamine (100 microg and 200 microg), as well as 2 negative controls (20 microL of water and methanol). We determined how likely these other indoles are to be mistaken for a positive alpha-amanitin Meixner reaction result by determining the percentage of positive sample interpretation for each compound and comparing them with the rate for alpha-amanitin. Fisher's exact test was used to determine any significant difference (P<.05) between the samples., Results: The minimum amount of alpha-amanitin that was identified with 100% agreement by testers was 2 microg. For the second part, there was 100% agreement that psilocin gives a positive Meixner test (100% false positive) and a 35% recognition rate of the 5-substituted tryptamine compounds as a positive Meixner test. There was no statistical difference between the interpretation of alpha-amanitin and psilocin, suggesting the test is unable to differentiate between them., Conclusion: Although the Meixner test has a good detection limit for toxic amounts of alpha-amanitin, a positive Meixner reaction does not adequately distinguish between alpha-amanitin and other mushroom indoles.

Study Objective: We describe our postmarketing experience with patients receiving Crotalidae polyvalent immune Fab (CroFab; FabAV) antivenom for treatment of rattlesnake envenomation., Methods: The charts of 28 patients admitted between March 1 and September 9, 2001, with rattlesnake envenomation and treated with FabAV were reviewed for demographic information, time until antivenom treatment, laboratory findings, evidence of hypersensitivity reaction, length of hospital stay, and readmission to the hospital., Results: All patients had swelling, 20 patients had elevated prothrombin times (>14 seconds), 12 patients had low fibrinogen levels (<170 mg/dL), and 6 patients had thrombocytopenia (platelet count <120,000/mm(3)) on presentation. The total dose of FabAV ranged from 10 to 47 vials per patient. Hypofibrinogenemia was resistant to FabAV in some patients. On follow-up, recurrence of coagulopathy was detected in 3 patients, and recurrence of thrombocytopenia was detected in 1 patient. Two patients demonstrated delayed-onset severe thrombocytopenia. Recurrence or delayed-onset toxicity might have been underestimated because of incomplete follow-up in some patients. No acute hypersensitivity reactions occurred. Two patients reported mild symptoms of possible serum sickness on follow-up., Conclusion: FabAV effectively controlled the effects of envenomation; however, initial control of coagulopathy was difficult to achieve in some cases, and recurrence or delayed-onset hematotoxicity was common. When initially managing hematotoxicity, a trend toward normalization of laboratory values might be a more reasonable end point for FabAV treatment than attainment of normal reference values in nonbleeding patients.

A 41-year-old woman ingested apricot kernels purchased at a health food store and became weak and dyspneic within 20 minutes. The patient was comatose and hypothermic on presentation but responded promptly to antidotal therapy for cyanide poisoning. She was later treated with a continuous thiosulfate infusion for persistent metabolic acidosis. This is the first reported case of cyanide toxicity from apricot kernel ingestion in the United States since 1979.

Study Objective: To review cases of black widow spider envenomation to describe the clinical presentation and evaluate the efficacy of treatment., Design: Retrospective chart review., Setting: An urban toxicology referral center., Type of Participants: All patients attended by the toxicology service and discharged from our hospital between January 1982 and December 1990 with a diagnosis of black widow spider envenomation., Interventions: Inclusion criteria were either a positive black widow spider identification or a visible envenomation site ("target lesion"). Depending on the clinical presentation, patients were categorized as grade 1, 2, or 3 in severity. The efficacy and side effects of treatment alternative were evaluated., Measurements and Main Results: One hundred sixty-three patients met the inclusion criteria. The most common sites of envenomation were the upper and lower extremities. The most common presenting complaint was generalized abdominal, back, and leg pain. One hundred eighteen patients initially presented to our institution, and 45 were transfers. Pain relief of grade 2 and 3 envenomations was achieved most effectively with either black widow spider-specific antivenin alone or a combination of IV opioids and muscle relaxants. Fifty-eight patients received antivenin with complete resolution of symptoms in a mean time of 31 +/- 26.7 minutes. Of the 118 patients initially seen at our institution, the mean total duration of symptoms was 9 +/- 22.7 hours in patients receiving antivenin and 22 +/- 24.9 hours in patients not receiving antivenin. Fifty-two percent of patients not receiving antivenin required hospitalization, whereas only 12% of those receiving antivenin were admitted. One patient died of severe bronchospasm after receiving antivenin. Calcium gluconate was not effective in providing symptomatic relief in this series, with 96% of the grade 2 and 3 envenomations treated initially with calcium gluconate requiring the addition of IV opioids or other analgesics for symptomatic relief. Fifty-five percent of patients initially receiving IV morphine and 70% of those initially receiving both IV morphine and benzodiazepines obtained symptomatic relief without additional medication., Conclusion: One hundred sixty-three envenomations by black widow spiders were reviewed and graded according to severity with treatment modalities evaluated. Although calcium gluconate usually has been considered the first-line treatment of severe envenomations by black widow spiders, we found it ineffective for pain relief compared with a combination of IV opioids and benzodiazepines. The use of antivenin significantly shortened the duration of symptoms in severe envenomations.

We cared for two rattlesnake bite victims who developed platelet counts of 21,000/mm3 and 22,000/mm3. Both had only mild defibrination without evidence of intravascular clotting. In both cases, the administration of antivenin was followed promptly by a sustained rise in platelet counts.

We describe the case of a 41-year-old man who suffered a bite to the tongue from the Western Diamondback rattlesnake (C atrox). Life-threatening obstruction of his upper airway secondary to massive edema of the tongue and other soft tissue structures quickly followed envenomation. Nasotracheal intubation, IV antivenin, and supportive care resulted in complete recovery with no permanent deficits. Rattlesnake bites to the tongue are rare and pose an unusual cause of airway obstruction.

We followed serial plasma baclofen concentrations in a woman who ingested more than 2 g of baclofen in a suicide attempt, the largest ingestion of baclofen reported to date. The plasma clearance of baclofen was characterized by first-order elimination kinetics with a half-life of 8.6 hours. The persistent central nervous system depression noted in our patient after the return of plasma baclofen levels to the therapeutic range is best explained by delayed clearance of baclofen from the CNS. She made a full recovery with supportive care. No evidence of saturable elimination kinetics was found.