A Model of Clinical Alarm Errors in Hospital

Although there has been much attention paid recently to clinical alarms, research has primarily focused on particular aspects of the clinical alarm problem, such as how to reduce nuisance alarms. This paper takes a broad view of clinical alarms and develops a model of errors in alarm handling and how they affect patients directly. Based on reports in the literature, I estimate that alarms that should sound by current standards do not sound about 9% of the time. Additionally, about 3% of alarms that are clinically significant are ignored, either intentionally or because they were inaudible. However, these errors produce a very low rate of reported alarm-related deaths and other adverse effects (on the order of a couple adverse effects per 10 million alarm errors). While it is not yet possible to estimate the probabilities of clinical alarms having an adverse impact on patients other than the patient whose alarm is sounding, such indirect adverse effects likely occur at a low level as a result of disruption of staff workflow, creation of a noisy hospital environment, and contribution to communication difficulties. Consideration of alarms should include not only the patient connected to the device that is sounding, but also the impact of the alarm on other patients in the vicinity.