Sixteen years of severe Tiger snake (Notechis) envenoming in Perth, Western Australia.

We aimed to describe the characteristics, clinical course, management and outcome of patients presenting to Perth teaching hospitals after envenoming by Tiger snakes. We undertook a chart review from six Perth teaching hospitals over a 16 year period from 1990 to 2005. Data were collected by a trained investigator using a preformatted data abstraction tool. We included patients bitten in the appropriate geographical area, with defibrination coagulopathy and positive Venom Detection Kit result for Tiger snake or response to specific antivenom. Of 381 charts reviewed, 23 patients were envenomed by a Tiger snake. The mean age was 36 years, 83% were male and all were bitten on a limb. First aid was applied poorly and all patients were symptomatic on presentation. Six patients developed rhabdomyolysis, one renal failure, four clinical bleeding, three neurotoxicity, one non-fatal respiratory arrest and one fatal cardiac arrest. All patients received antivenom, 13 received adrenaline premedication, with two mild allergic reactions developing in non-premedicated patients. The average dose of antivenom was four ampoules. Mean hospital stay was 2.6 days. This is the largest series of Tiger snake envenoming reported in Australia. Only one patient of 23 (4%) died, despite all patients being significantly envenomed. With rapid antivenom treatment and modem emergency and intensive care management, most patients envenomed by Tiger snakes survive.

Correlation of paired plasma and saliva paracetamol levels following deliberate self-poisoning with paracetamol (the Salivary Paracetamol In Toxicology [SPIT] study).

AIM: To determine the correlation between plasma and saliva paracetamol levels following paracetamol deliberate self-poisoning. METHODS: Paired plasma and saliva paracetamol levels were measured. Saliva analysis was performed contemporaneously using a colorimetric method. RESULTS: 21 patients (76% female) mean age 28.3 +/- 12.9 years (range 15-55) were enrolled. Mean reported paracetamol ingestion was 10.3 g (range 2-20 g). Specimens were collected at a mean of 6.2 +/- 3.1 hours post-ingestion (range 4-13 hours) and mean plasma and saliva paracetamol levels were 48 mg/L and 62 mg/L respectively (mean difference 14; 95% CI 5-22; p < 0.004); Pearson's correlation r = 0.95 (p < 0.0001). No patient needing treatment would have been missed using saliva levels only. CONCLUSION: There is concordance between the indications for treatment of paracetamol deliberate self-poisoning based on plasma and saliva paracetamol levels. Saliva paracetamol levels are typically higher than plasma levels. Further studies involving larger numbers of patients, comparing plasma and saliva paracetamol levels in patients with potentially toxic plasma paracetamol concentrations, would be useful in determining the potential clinical value of this method.

Toxicology case of the month: Carbamazepine overdose.

A 29-year-old woman presents shortly after a massive overdose of carbamazepine controlled-release tablets. In anticipation of coma, she is electively intubated to safely enable gastrointestinal decontamination with nasogastric activated charcoal. She is admitted to the intensive care unit for ongoing supportive care, and further doses of activated charcoal are prescribed to enhance elimination of carbamazepine. Carbamazepine levels remain high and haemodialysis is carried out to further enhance elimination. Her coma resolves as levels fall, but clinical progress is complicated by anticholinergic delirium, ileus and bowel obstruction from charcoal concretions. She survives to medical discharge on day 12.

Toxicology case of the month: ingestion of two unidentified tablets by a toddler.

An asymptomatic 18 month old child presents to the emergency department of a small district hospital shortly after ingesting two unidentified tablets. A small number of pharmaceuticals and illicit drugs may produce life threatening toxicity in a small child if ingested even in one or two dose units and the onset of toxicity may be delayed for some agents. Following risk assessment, a rational management plan is devised and the child is carefully monitored. The patient is observed overnight and discharged home the following day.

Toxicology case of the month: oral hypoglycaemic overdose.

A teenager ingests 375 mg of glipizide and 14.5 g of melformin intentionally in a small country town. She presents to the local medical facility with symptoms and signs of hypoglycaemia. Using a risk assessment based approach, the management of suiphonylurea and metformin overdose is discussed. Sulphonylurea overdose invariably results in profound hypoglycaemia that requires resuscitation with IV dextrose and the use of octreotide as an antidote. Metfonnin overdose rarely causes problems.

A risk assessment based approach to the management of acute poisoning.

Early assessment and management of poisoning constitutes a core emergency medicine competency. Medical and psychiatric emergencies coexist; the acute poisoning is a dynamic medical illness that represents an acute exacerbation of a chronic underlying psychosocial disorder. The emergency physician must use an approach that ensures early decisions address potentially time critical interventions, while allowing management to be tailored to the individual patient's needs in that particular medical setting. This article outlines a rationale approach to the management of the poisoned patient that emphasises the importance of early risk assessment. Ideally, this approach should be used in the setting of a health system designed to optimise the medical and psychosocial care of the poisoned patient.

Neutralization of Latrodectus mactans and L. hesperus venom by redback spider (L. hasseltii) antivenom.

OBJECTIVE: To test the effectiveness of L. hasseltii (redback spider) antivenom in neutralizing the lethal effects of L. hesperus and L. mactans (North American black widow) venoms. METHODS: LD50 values for the L. hesperus and L. mactans venom preparations were determined. A prospective, randomized, double-blind antivenom efficacy experiment was then performed for each venom using a mouse envenomation model. The following treatments were premixed and incubated at 25 degrees C for 1 hour prior to intraperitoneal injection: 1) saline control + protein control, 2) saline control + L. hasseltii antivenom, 3) L. hesperus or L. mactans venom + protein control, and 4) L. hesperus or L. mactans venom + L. hasseltii antivenom. The study endpoints were time elapsed until death and survival at 24 hours. RESULTS: The mouse LD50 values for L. hesperus and L. mactans venoms were 0.64 mg/kg and 0.26 mg/kg, respectively. In the efficacy trial, all mice in group 3 (L. hesperus or L. mactans venom and protein control) died. In both experiments, all mice in group 4 (L. hesperus or L. mactans venom + antivenom) survived (p < 0.0001). CONCLUSION: This is the first study to derive mouse LD50 values for L. hesperus and L. mactans venom obtained by electrical stimulation of live adult spiders. Redback spider antivenom is effective in neutralizing the lethal effects of L. hesperus and L. mactans venoms in a mouse envenomation model. While this study is limited by the optimized premixing of antigen with antibody, it generates the hypothesis that redback antivenom would be effective in the treatment of latrodectism in humans caused by the two clinically relevant species of North American widow spiders.

Acute myocardial infarction associated with amphetamine use.

Myocardial infarction is a rarely reported complication of amphetamine use. We report the case of a healthy 31-year-old man who presented to our emergency department with no clinical evidence of an acute coronary event after intravenous injection of amphetamines. However, he subsequently experienced a non-Q-wave anterior wall myocardial infarction associated with the use of amphetamines.

The Medical Emergency Team (MET): a model for the district general hospital.

BACKGROUND: Most hospitals have a Cardiac Arrest Team, activated after cardiopulmonary arrest. The Medical Emergency Team (MET) is a newer concept, encompassing a proactive response to a wide range of emergencies with the aim of preventing irreversible organ failure and cardiopulmonary arrest. AIM: To describe the application of the MET model to the district general hospital, the spectrum of clinical conditions encountered, outcomes and administrative problems. METHOD: Data regarding each MET activation was collected prospectively. RESULTS: The MET responded to 68 calls to 63 patients in 12 months. The mean age was 60.4 years (range: neonatal to 94 years). The most common conditions leading to MET activation were chest pain (19.1%), cardiopulmonary arrest (14.7%), seizures (14.7%) and respiratory distress (13.2%). CONCLUSION: This paper demonstrates that the application of the MET model to the district general hospital improves the process of patient care. We are unable to conclude whether the MET alters morbidity or mortality for hospital inpatients.