The ANTS system is a hierarchical structure consisting of four categories, each of which is divided into a number of elements. The elements are supported by a set of behavioral markers that serve an illustrative purpose to help make them more comprehensible and so applicable. This approach has also been successfully used in other high-reliability industries.5
A simple clinical example will demonstrate how the system can be used to reflect on clinical performance. Let us consider the following scenario. An attending anesthesiologist (Dr. A) has just taken up a post in hospital Z. Orientation to the main operating room (OR) suite, but not anesthesia sites outside of the OR suite, has taken place. Due to unexpected circumstances Dr. A has been asked to take over at late notice from Dr. B (who had phoned in sick). Dr. A now finds himself in an OR distant from the main OR complex, already behind schedule and under pressure to proceed. Having induced anesthesia in the first patient, he discovers that the surgeon, Dr. C, is using a camera technique and wishes the OR lights dimmed. Dr. A reaches for where he thinks the anesthetic machine light switch should be. However, he inadvertently presses the power switch for the anesthetic machine (different from those in the main OR suite) and now finds himself in the dark with no gas flow, no ventilation for his paralyzed patient, and no monitoring.
If we review how Dr. A got into this situation, then the key category is Situation Awareness (or rather, lack of). This has three elements, gathering information (Dr. A did not find out information about the anesthetic machine), making sense of what is happening , and anticipation. If Dr. A had gathered more information from Dr. C or the OR nurses (exchanging information from the category Team Working ) or had used authority and assertiveness (also from Team Working ) to say to Dr. C, “There will be a delay because I have to familiarize myself with the environment” (gathering information ). Then, he may have anticipated the reduced lighting and may have formulated a plan (Task Management ) to deal with those circumstances. Under the category of Decision Making , it would appear that Dr. A either did not identify options or did not balance the risks when selecting this option . The pressures on Dr. A to act as he did are understandable, but application of the relevant NTS may have provided countermeasures to the subsequent errors. A definition and list of behavioral markers for the element gathering information is provided in table 2.