Development of a Low-Cost, High-Fidelity, Reusable Model to Simulate Clamshell Thoracotomy.

OBJECTIVE: Clamshell thoracotomy (CST) is an emergency procedure performed during traumatic cardiac arrest. Emergency physicians and surgeons are expected to perform this procedure in the Emergency Department. However, the procedure has a low occurrence rate, therefore physicians are often poorly prepared. Current teaching methods include expensive simulators and anatomically inaccurate animal models. The goal of this study was to design, produce and test, a low-cost, high-fidelity model for the teaching of CST. DESIGN, SETTING AND PARTICIPANTS: The model was produced from inexpensive, commercially available materials as well as ADAMgel; a custom, recyclable, inexpensive tissue analogue. The model was tested across 19 physicians, mostly consultants and senior registrars in emergency medicine, anaesthesia and surgery. Participants completed comparative questionnaires before and after testing the model. The questionnaires were adapted from previous anaesthetic-based simulation studies and used a modified Likert scale to assess prior knowledge, anatomical realism and the teaching benefits of the model. RESULTS: Participants had varied prior knowledge and experience before testing the model. Results showed that 89.47% (n = 17) of trainees felt the model was a reasonable substitute for practice and 100% (n = 19) agreed that the model was a good training aid for inexperienced trainees and would recommend it to others. CONCLUSIONS: The model proved a successful teaching tool, improving physicians' knowledge and confidence with performing CST. This high fidelity, low cost model demonstrated that a high standard simulation teaching tool can be made which improves teaching of CST.

LIPAEMIC report: results of clinical use of intravenous lipid emulsion in drug toxicity reported to an online lipid registry.

The use of intravenous lipid emulsion (ILE) as an antidote has prompted significant academic and clinical interest. Between August 2009 and August 2012, data from cases of ILE use in intoxicated patients in different hospitals on different continents were voluntarily entered into a registry based on the world wide web (www.lipidregistry.org). Here, we report data from this project. Participating centers were given access to the registry following institutional subscription. Specifically sought were details of the individual patients' presenting condition, indications for ILE use, ILE administration regimen, potential complications, and of clinical outcome. Forty-eight uses of ILE were reported from 61 participating centers. Ten cases of local anesthetic systemic toxicity were reported; all (10/10) survived. Thirty-eight cases of intoxication by other agents were reported [30 decreased conscious state, 8 cardiovascular collapse (3 deaths)]. There was an elevation in GCS (p < 0.0001) and increased systolic blood pressure (p = 0.012) from immediately prior to ILE administration to 30 min after use. One serious and two minor adverse effects of ILE use were recorded in 48 reported cases (one case of bronchospastic reaction, one case of hyperamylasemia and one case of interference with laboratory testing). In this series of cases reported to the registry, improvements were seen for GCS in patients with central nervous system toxicity and in systolic blood pressure in shocked patients over a short time frame after the injection of ILE. Few adverse effects were recorded. Clinical trials and the reporting of drug concentrations after ILE use are necessary to further elucidate the role of ILE in clinical toxicology.

Progressive encephalomyelitis with rigidity and myoclonus: anesthesia and glycine receptor antibodies.

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare autoimmune neurological condition. Antibodies targeting glycine receptors (GlyR) have been implicated in PERM. Because GlyR activity is enhanced by inhaled anesthetic drugs at clinically relevant concentrations, there is a theoretical possibility that these drugs may be less effective in the presence of GlyR antibodies. We describe a case of general anesthesia in a patient with PERM and GlyR antibodies. This patient did not demonstrate a clinically significant alteration in the behavioral effects of anesthesia using induction of anesthesia with sevoflurane and maintenance of anesthesia using sevoflurane and nitrous oxide.

The use of dye surrogates to illustrate local anesthetic drug sequestration by lipid emulsion: a visual demonstration of the lipid sink effect.

BACKGROUND AND OBJECTIVES: We hypothesized that by substituting a dye surrogate in place of local anesthetic, we could visually demonstrate dye sequestration by lipid emulsion that would be dependent on both dye lipophilicity and the amount of lipid emulsion used. METHODS: We selected 2 lipophilic dyes, acid blue 25 and Victoria blue, with log P values comparable to lidocaine and bupivacaine, respectively. Each dye solution was mixed with combinations of lipid emulsion and water to emulate "lipid rescue" treatment at dye concentrations equivalent to fatal, cardiotoxic, and neurotoxic local anesthetic plasma concentrations. The lipid emulsion volumes added to each dye solution emulated equivalent intravenous doses of 100, 500, and 900 mL of 20% Intralipid in a 75-kg adult. After mixing, the samples were separated into a lipid-rich supernatant and a lipid-poor subnatant by heparin flocculation. The subnatants were isolated, and their colors compared against a graduated dye concentration scale. RESULTS: Lipid emulsion addition resulted in significant dye acquisition by the lipid compartment accompanied by a reduction in the color intensity of the aqueous phase that could be readily observed. The greatest amount of sequestration occurred with the dye possessing the higher log P value and the greatest amount of lipid emulsion. CONCLUSIONS: Our study provides a visual demonstration of the lipid sink effect. It supports the theory that lipid emulsion may reduce the amount of free drug present in plasma from concentrations associated with an invariably fatal outcome to those that are potentially survivable.