Abstract. Emergency medicine (EM) presents many cognitive, social, and systems challenges to practitioners. Coordination and communication under stress between and among individuals and teams representing a number of disciplines are critical for optimal care of the patient. The specialty is characterized by uncertainty, complexity, rapidly shifting priorities, a dependence on teamwork, and elements common to other risky domains such as perioperative medicine and aviation. High-fidelity simulators have had a long tradition in aviation, and in the past few years have begun to have a significant impact in anesthesiology. A national, multicenter research program to document the costs of teamwork failures in EM and provide a remedy in the form of an Emergency Team Coordination Course has developed to the point that high-fidelity medical simulators will be added to the hands-on training portion of the course. This paper describes an evolving collaborative effort by members of the Center for Medical Simulation, the Harvard Emergency Medicine Division, and the MedTeams program to design, demonstrate, and refine a high-fidelity EM simulation course to improve EM clinician performance, increase patient safety, and decrease liability. The main objectives of the paper are: 1) to present detailed specifications of tools and techniques for high-fidelity medical simulation; 2) to share the results of a proof-of-concept EM simulation workshop introducing multiple mannequin/ three-patient scenarios; and 3) to focus on teamwork applications. The authors hope to engage the EM community in a wide-ranging discussion and handson exploration of these methods. Key words: patient safety; performance; teamwork; team training; emergency medicine; simulation. ACADEMIC EMER- GENCY MEDICINE 1999; 6:312 -323 T HE PRACTICE of emergency medicine (EM) presents many cognitive, social, and systems challenges to clinicians and administrators. Education of emergency physicians (EPs) must optimally include training to manage the self, team, and environment under difficult conditions. Naturalistic decision making (NDM) is a growing school of thought that has led to greater understanding of how skilled people solve complex problems in the actual contexts in which tasks must be carried out. Job performance in EM can be characterized as consisting of the eight task and setting factors that serve as a framework for the NDM movement (Table 1).

RRHCT is unnecessary in patients with MHI. Clinical examination identifies accurately the few who will show significant evolution and require intervention.