Normal accidents: human error and medical equipment design.

High-risk systems, which are typical of our technologically complex era, include not just nuclear power plants but also hospitals, anesthesia systems, and the practice of medicine and perfusion. In high-risk systems, no matter how effective safety devices are, some types of accidents are inevitable because the system's complexity leads to multiple and unexpected interactions. It is important for healthcare providers to apply a risk assessment and management process to decisions involving new equipment and procedures or staffing matters in order to minimize the residual risks of latent errors, which are amenable to correction because of the large window of opportunity for their detection. This article provides an introduction to basic risk management and error theory principles and examines ways in which they can be applied to reduce and mitigate the inevitable human errors that accompany high-risk systems. The article also discusses "human factor engineering" (HFE), the process which is used to design equipment/ human interfaces in order to mitigate design errors. The HFE process involves interaction between designers and endusers to produce a series of continuous refinements that are incorporated into the final product. The article also examines common design problems encountered in the operating room that may predispose operators to commit errors resulting in harm to the patient. While recognizing that errors and accidents are unavoidable, organizations that function within a high-risk system must adopt a "safety culture" that anticipates problems and acts aggressively through an anonymous, "blameless" reporting mechanism to resolve them. We must continuously examine and improve the design of equipment and procedures, personnel, supplies and materials, and the environment in which we work to reduce error and minimize its effects. Healthcare providers must take a leading role in the day-to-day management of the "Perioperative System" and be a role model in promoting a culture of safety in their organizations.