Faculty Bibliography

INTRODUCTION: Poisoning from organophosphates and carbamates is a significant cause of morbidity and mortality worldwide. Concerns have been expressed over the safety and efficacy of the use of oximes such as pralidoxime (2-PAM) in patients with carbamate poisoning in general, and more so with carbaryl poisoning specifically. The goal of the present study was to evaluate the role of 2-PAM in a mouse model of lethal carbaryl poisoning. METHODS: Female ICR Swiss Albino mice weighing 25-30 g were acclimated to the laboratory and housed in standard conditions. One hundred and ten mice received an LD50 dose of carbaryl subcutaneously. Ten minutes later, they were randomized by block randomization to one of eight treatment groups: normal saline control, atropine alone, 100 mg/kg 2-PAM with and without atropine, 50 mg/kg 2-PAM with and without atropine, and 25 mg/kg 2-PAM with and without atropine. All medications were given intraperitoneally and the atropine dose was constant at 4 mg/kg. The single objective endpoint was defined as survival to 24 hours. Fatalities were compared using a Chi squared or Fisher's exact test. RESULTS: Following an LD50 of carbaryl, 60% of the animals died. Atropine alone statistically improved survival (15% lethality). High dose 2-PAM with and without atropine was numerically worse, but not statistically different from control. While the middle dose of 2-PAM was no different than control, the addition of atropine improved survival (10% fatality). Low-dose 2-PAM statistically improved survival (25% lethality). Atropine further reduced lethality to 10%. CONCLUSION: When appropriately dosed, 2-PAM alone protects against carbaryl poisoning in mice. Failure to demonstrate this benefit in other models may be the result of oxime overdose

INTRODUCTION: Poison Control Centers (PCCs) play an integral role in the preparation for and management of poison emergencies. Large-scale public health disasters, caused by both natural and human factors, may result in a drastic increase in the number of inquiries received and handled by PCCs in short periods of time. In order to plan and prepare for such public health emergencies, it is important for PCCs to assess their ability to handle the surge in call volume and to examine how the unusually large number of calls could affect the level of services. On 26 January 2006, the New York City Poison Center experienced a sudden loss of telephone service. The disruption in telephone service led to the need to reroute calls from that geographical catchment area to the New Jersey Poison Information and Education System (NJPIES) for several hours. METHODS: Data from the NJPIES was abstracted from the telephone switch's internal reporting system and the NJPIES's electronic record system and processed with a standard spreadsheet application. RESULTS: Compared to the same time and day in the previous week, the total number of calls received by the NJPIES during the four hours after the disruption increased by 148%. A substantial rise in the number of calls was observed in almost every 15-minute increment during this four-hour (h) time period (with some of these increments increasing as much as 525%). Meanwhile, the percentage of calls answered by the NJPIES decreased, and the percentage of calls abandoned during a 15-minute increment reached as high as 62%. Furthermore, the average time for handling calls was longer than usual in most of these 15-minute increments. CONCLUSIONS: Limitations of the telephone technology, which impacted the ability of the NJPIES to respond to the surge of calls, were observed. While the NJPIES was able to handle the unusual increase of incoming calls using available poison specialists and staff, the experience gained from this natural experiment demonstrates the need for PCCs to have a pre-planned surge capacity protocol that can be implemented rapidly during a public health emergency. A number of challenges that PCCs must meet in order to have adequate surge capacity during such events were identified

Treatment of hypotension caused by calcium channel blocker overdose (CCB) remains a challenge. We describe the successful use of vasopressin in two patients with massive CCB overdoses in whom hypotension was unresponsive to calcium, glucagon, insulin, and conventional vasopressor therapies. While various modes of treatments have been used to treat the hypotension of CCB overdose, this is the first report to our knowledge of the successful use of vasopressin in this clinical setting

INTRODUCTION: Cardioactive steroids (CASs) are found in plants, animals, and insects. Their affinity for Na+-K+ ATPase is attenuated by the type of lactone at carbon 17 (C17) of the steroid backbone: those with 5-membered lactone rings, or cardenolides, are derived mostly from plants with 6-membered rings or from animals with bufadienolides. A systematic review of CAS poisoning was performed to compare the mortality rate of cardenolides and bufadienolides. METHODS: MEDLINE was searched for articles using commonly reported names of CASs, and keywords were limited to human cases only. We searched cases from 1982 to 2003, so that supportive care was similar and digoxin-specific Fab was available. Identified reports of CAS poisoning were read to exclude cases involving licensed pharmaceuticals. Inclusion criteria included hyperkalemia, gastrointestinal symptoms, electrocardiographic evidence of CAS toxicity, digoxin serum concentration, or history of exposure to a substance containing a CAS. Clinical data was collected, including information about treatment with digoxin-specific Fab and treatment outcome. RESULTS: Fifty-nine articles, describing 924 patients, were identified. Eight hundred ninety-seven patients (97%) ingested a CAS with a 5-membered lactone ring, and mortality was 6% (n = 54). Twenty-seven patients (2.9%) ingested a CAS with a 6-membered lactone ring, and mortality was 29.6% (n = 8). The difference in mortality rates was statistically significant (p < 0.001, [X2]). CASs with 6-member rings accounted for the highest percentage of nonsuicidal exposures. CONCLUSION: Although cardenolides accounted for the majority of exposures, bufadienolides were five times more lethal than cardenolides

Ingestion of strontium ferrite is previously unreported. We document absorption of strontium without acute toxicity. A 22 year-old schizophrenic man was brought to hospital after he was witnessed to pulverize and ingest flexible adhesive magnets, which later were identified as strontium ferrite. Other than auditory hallucinations his vital signs, physical examination, ECG and routine laboratories were unremarkable. Abdominal radiographs revealed diffuse radiopaque material. He was treated with whole bowel irrigation with polyethylene glycol electrolyte lavage solution (PEG-ELS) until radiographically cleared. His initial blood and urine strontium levels were 2900 microg/l and 15,000 microg/l, respectively (reference range for urine: <240 microg/l, occupational threshold 800 microg/l). A repeat urine level one week later was 370 microg/l. His hospital course was complicated by bacteraemia secondary to a thrombophlebitis at the site of the intravenous catheter, and the patient was treated with intravenous and oral antibiotics. He remained otherwise asymptomatic and was discharged to a psychiatric unit approximately 3 weeks later. Although clearly absorbed, strontium ferrite does not appear to produce acute toxicity. Delayed, and or chronic toxicity cannot be excluded based on this report