Fault Tree Analysis of Clinical Alarms

Abstract

Clinical alarms have a deceptively simple purpose, which is to notify caregivers when a patient or a device needs their attention. This simple concept has been proven to be challenging as the number of available alarms has grown and been poorly integrated. When an anticipated notification is not received or an actual notification is not acted upon in a timely manner, patient harm can occur. In this regard, false alarms have been proven to be highly detrimental to the effective use of clinical alarms to enhance patient care. Equally problematical is the issue of false reliance in which a clinician’s vigilance is degraded by the expectation that if anything bad happens, the system will notify him or her. Similarly, alarms have also been part of staff downsizing and shifting to lower expertise, wherein it is believed that the alarms are an appropriate substitute. Human factor issues associated with setting, observing, and responding to alarms have also been proven to be inadequately addressed. This article presents a fault tree analysis of the patient harm-related clinical alarms failures. This analysis can be used to understand, debate, and educate. Medical device alarms continue to be a challenging area of clinical engineering and hospital patient care, and the subject continues to receive a great deal of scrutiny. 1-7 Alarms have the clear purpose of improving patient care by calling an attendant’s attention to a situation that may require his or her intervention. In many cases, each of the potential alarms must be set by the user with respect to a number of alarm parameters including on/off, upper/lower limit, volume of the alarm sound, and possibly a connection to or activation of a remote alarm notification location or system. This can involve a significant number of settings over a range of parameters and across a number of individual devices. Each of these settings may include default values that might be locally set or set by the manufacturer. When there are default values, it can be important when the device does or does not reset to the defaults. An alarm may be triggered by a patient parameter (eg,