Naren Gunja

Energy drinks: health risks and toxicity

Objectives: To describe the epidemiology and toxicity of caffeinated energy drink exposures in Australia.

Senior Streaming Assessment Further Evaluation after Triage zone: A novel model of care encompassing various emergency department throughput measures

Objective: Access block (AB) and hospital overcrowding adversely affect ED functionality. ED throughput measures have been described in the literature with positive impacts on key performance indicators (KPIs) – time to first seen, did‐not‐wait rates, off‐stretcher times for ambulances and ED length of stay figures. In this study, we aimed to assess the impact of a new model of care, the Senior Streaming Assessment Further Evaluation after Triage (SAFE‐T) zone concept on ED performance indicators and statistical outcomes.

Management of intentional superwarfarin poisoning with long-term vitamin K and brodifacoum levels

Context. Brodifacoum is a widely available superwarfarin used as a commercial rodenticide. Toxicity from long-acting anticoagulant rodenticides, primarily from uncontrolled bleeding, has been reported. Very little published toxicokinetic data are available for human brodifacoum poisoning. Management is also contentious with uncertainty over the dose, frequency, and duration of antidote treatment with vitamin K. The role of brodifacoum levels in guiding management is not entirely established. Methods. A novel, highly sensitive method was developed for measuring all commercially available rodenticide-hydroxycoumarin anti-coagulants. Monthly brodifacoum levels were performed in two patients to determine half-life and expected time for levels to fall below 10 μg/L. Results. We report two concurrent cases at our clinical toxicology service that required prolonged treatment with oral vitamin K to achieve normalisation of coagulation studies. Brodifacoum elimination appears to follow first-order kinetics. Case 1 had a brodifacoum elimination half-life of 33 days and was treated with vitamin K (100 mg) for 6 months. Case 2 was treated with vitamin K (100 mg) for 3 months with a half-life of 15 days. Discussion. Our cases illustrate the positive experience in the utility of brodifacoum levels to confirm diagnosis and aid in directing antidote therapy. Large ingestions of brodifacoum-containing rodenticides are likely to require high-dose oral vitamin K administered daily. A brodifacoum level below 10 μg/L was associated with a normal coagulation profile following completion of vitamin K1 therapy in our cases; this level may prove to be a safe treatment cessation threshold.

Brainstem anaesthesia after retrobulbar block: a rare cause of coma presenting to the emergency department.

Local anaesthesia, in particular retrobulbar block, is commonly used to perform cataract surgery. Known complications of retrobulbar block include cranial nerve palsies, seizures and cardiorespiratory arrest. We report a case of brainstem anaesthesia causing apnoea and loss of consciousness in a man who received retrobulbar block. The likely mechanism is inadvertent dural puncture of the optic nerve sheath and local anaesthetic injection into the cerebrospinal fluid space. As in this case, the literature reports a short‐lived period of anaesthesia with usually no long‐term sequelae. Although rare, it is a life‐threatening complication if the patient is not appropriately resuscitated. This case highlights the need for trained personnel, with suitable monitoring and adequate resuscitation facilities in order to perform this technique.

Management of cardiac arrest following poisoning

Toxic cardiac arrest is an uncommon manifestation of poisoning. Patients might benefit from resuscitative measures that are over and above those recommended in standard ACLS resuscitation guidelines. Extraordinary resuscitative measures might include the use of toxin‐specific antidotes, prolonged CPR and/or other measures to bypass the poisoned myocardium (such as extra‐corporeal membrane oxygenation). Treating medical staff should seek expert advice from a toxicologist or from their Poisons Information Centre network (Australia 13 11 26; New Zealand 0800 764 766) at the earliest opportunity when managing patients with cardiac arrest or intractable shock from known or suspected poisoning. Ideally, toxicological expertise should be sought before the withdrawal of active treatment in cardiac arrest or shock from known or suspected poisoning.

A Validated LC -MS-MS Method for Simultaneous Identification and Quantitation of Rodenticides in Blood

A rapid, highly sensitive and specific analytical method for the extraction, identification and quantification of nine rodenticides from whole blood has been developed and validated. Commercially available rodenticides in Australia include coumatetralyl, warfarin, brodifacoum, bromadiolone, difenacoum, flocoumafen, difethialone, diphacinone and chlorophacinone. A Waters ACQUITY UPLC TQD system operating in multiple reaction monitoring mode was used to conduct the analysis. Two different ionization techniques, ES+ and ES-, were examined to achieve optimal sensitivity and selectivity resulting in detection by MS-MS using electrospray ionization in positive mode for difenacoum and brodifacoum and in negative mode for all other analytes. All analytes were extracted from 200 µL of whole blood with ethylacetate and separated on a Waters ACQUITY UPLC BEH-C18 column using gradient elution. Ammonium acetate (10 mM, pH 7.5) and methanol were used as mobile phases with a total run time of 8 min. Recoveries were between 70 and 105% with limits of detection ranging from 0.5 to 1 ng/mL. The limit of quantitation was 2 ng/mL for all analytes. Calibration curves were linear within the range 2-200 ng/mL for all analytes with the coefficient of determination ≥0.98. The application of the proposed method using liquid-liquid extraction in a series of clinical investigations and forensic toxicological analyses was successful.

Decontamination and enhanced elimination in sustained-release potassium chloride poisoning*

Potassium chloride poisoning can be potentially life‐threatening, particularly in massive ingestions of sustained‐release preparations. Profound hyperkalaemia, developing over several hours, can lead to cardiac arrhythmias and death. This case series reports three episodes of sustained‐release potassium chloride poisoning in two individuals requiring whole bowel irrigation or haemodialysis. The first two episodes, in the same patient, illustrate the contrast between the successful use of decontamination versus the need for haemodialysis. The second case, in a child, illustrates the need for tertiary level paediatric expertise in managing this type of poisoning. Whole bowel irrigation with polyethylene glycol is a resource‐intensive procedure most beneficial when large numbers of radio‐opaque tablets are seen in the stomach. In cases where most of the tablet matter has already been absorbed, extracorporeal methods of rapidly reducing the total body burden of potassium, such as haemodialysis, might be life‐saving.

Chemical agents for the sedation of agitated patients in the ED: a systematic review.

OBJECTIVE Chemical agents commonly used to sedate agitated patients in the emergency department include benzodiazepines, antipsychotics, or a combination of the 2 classes. Our objective was to determine if a class or combination therapy is (1) more effective, as measured by the proportion sedated at 15-20 minutes and the need for repeat sedation, and (2) safer, as measured by the proportion of reported adverse events. METHODS Systematic literature review and meta-analysis of studies comparing 2 or more chemical agents for sedation of agitated patients in the emergency department were carried out in PubMed, PsycINFO, Embase, and the Cochrane database. Meta-analyses for pairwise comparisons of drug class (benzodiazepine, antipsychotic, or combination) were carried out for each outcome: proportion sedated, need for repeat sedation, and adverse events. RESULTS Seven studies with 1135 patients were included. At 15-20 minutes, the proportion of patients sedated was greater with combination therapy than benzodiazepines alone (risk ratio [RR] = 1.31, P < .0001). Antipsychotics and combination agents required significantly less repeat sedations than benzodiazepines alone (RR = 0.49, P < .0001 and RR = 0.64, P = .002). There was significant heterogeneity in adverse event data, with respiratory system adverse events (desaturation, and need for airway and ventilatory support) being the most commonly reported. Benzodiazepines were associated with a higher incidence of adverse events than antipsychotics or combination therapy. CONCLUSION Combination therapy sedated a greater proportion of patients at 15-20 minutes than benzodiazepines alone. Antipsychotics and combination therapy were more effective, requiring less repeat doses for sedation than benzodiazepines. The risk of any adverse event was higher with benzodiazepines.

Accuracy of computed tomography of the kidneys, ureters and bladder interpretation by emergency physicians.

The study aims to determine the interpretation accuracy of computed tomography of the kidneys, ureters and bladder (CT‐KUB) by emergency physicians (EPs) compared with the formal radiology report, as the reference standard, in patients with suspected acute urinary tract calculous disease.

Transporting children with toxicological emergencies.

Each year, the Newborn and Paediatric Emergency Transport Service (NETS) receives over 3600 calls from health professionals regarding the management and transportation of critically ill children across New South Wales, with toxicological emergencies making up 1.5% of these calls. The aim of the present study is to describe the characteristics of patients transported for toxicological emergencies and their retrieval management.