The Effects of Task Demands and the Anaesthetic Machine on the Anaesthetists’ Mental Workload

Abstract

Mental workload refers to the demands that are imposed on the human cognitive system through the performance of a given task (Sweller, van Merriënboer, & Paas, 1998). As humans, we have a limited cognitive capacity for processing information (Sweller, 1988). During periods of high mental workload, when there is insufficient available cognitive resources to meet the demands of a task, task performance can deteriorate, and situation awareness can be lowered. In anaesthetists, high levels of mental workload can increase the risk of adverse events. The aims of this research is to investigate how the task demands in anaesthetic delivery can affect the anaesthetists’ level of mental workload; and how the anaesthetists’ mental workload can be influenced by three aspects of the anaesthetic machine (automation, the monitor display, and the auditory alarms). This research was conducted through observations and interviews. A total of 17 anaesthetists have been observed as they were delivering anaesthetics to patients in the operating theatre. The results showed that for most of the participants, an increase in task demands was associated with an increase in mental workload. This relationship between mental workload and task demands was influenced by three other factors: the phase of anaesthetic delivery, individual variations, and multi-tasking. A total of 11 semi-structured interviews were conducted. The findings show that the automated system, the monitor display, and the auditory alarms in the anaesthetic machine, as well as the participants’ level of experience with that machine, have had an impact on the participants’ mental workload. However, these effects on mental workload can vary widely across participants and across different situations.