ABSTRACT
Introduction Hospital emergency departments (EDs) are complex, dynamic settings where successful and effective work must occur in the face of high consequences of failure, and where practitioners are operating under conditions of time and resource constraints, physical stress (noise, fatigue), uncertainty, engaged in a multiplicity of tasks and resolving competition among goals, many of which are ill-defined, shifting, or ambiguous. ED work is made even more difficult because it is inherently limited to reacting to events – there is no possibility of seizing the initiative and controlling the pace of events (e.g., as a military unit might do by going on the attack), or even of preparing for impending events in anything other than the most general way.
