Frequency of Clinical Alarms in Intensive Care Units and Nurses' Sensitivity to Them

An Observational Study

Burcu Ceylan, PhD, RN; Leyla Baran, PhD, RN; Ülkü Yapucu Güneş, PhD, RN


Am J Crit Care. 2021;30(3):186-192. 

In This Article

Abstract and Introduction


Background: All clinical alarms require nurses to respond even if an intervention is not needed. Nurses are expected to respond appropriately to each alarm and establish priorities among their care practices accordingly. This study was conducted to examine the number and types of clinical device alarms used in intensive care units, the duration of their activation, and nurses' degree of sensitivity to them.

Methods: This observational study was conducted in 4 intensive care units in a university hospital in Turkey. A total of 20 nurses (5 from each unit) were observed for a total of 80 hours. The alarms were categorized as valid, false, or technical.

Results: During the study observation period, the mean number of alarms sounding per hour per bed was 1.8. A total of 144 alarms were recorded, of which 70.8% were valid, 15.3% were false, and 13.9% were technical. The mean duration of alarm activation was 8 minutes for valid alarms, 14 minutes for false alarms, and 53 minutes for technical alarms.

Conclusions: Nurses' responses to alarms differ depending on alarm type; for alarms that do not require an emergency intervention, nurses tend to respond late or not at all.


Clinical alarms are alarms that alert health care personnel to an emergency or a patient's urgent needs.[1] The Joint Commission has acknowledged that improper management of clinical alert signals may compromise patients' health.[2] In 2013 the Joint Commission turned its attention to the safety of medical device alarm systems.[2] Subsequently, it identified the national patient safety goals of improving the safety of clinical alarm systems in 2014 and reducing the damage caused by clinical alarm systems in 2015.[3,4]

In the hospital setting, various devices emit ringing and beeping sounds and other types of alerts.[5] Although electrocardiographs, pulse oximeters, bedside monitors, infusion pumps, ventilators, and other devices are essential in providing patient care, their frequent alerts may result in "alarm fatigue" among nurses and other health care personnel, a state that can put patient safety at risk.[2] The number of alarms sounding for every patient every day in the various units of a hospital may reach several hundred. It is estimated that 85% to 99% of these signals are either false alarms or clinically insignificant.[6] Studies have shown that most clinical alarms are false alarms.[2,7,8] This high frequency of unnecessary alarms can contribute to alarm fatigue.[9]

Alarm fatigue is related to the sensory burden that clinical nurses carry when they are exposed to a large number of alarms. This burden leads to desensitization to alarms and may result in missing a valid alarm as well as experiencing extreme stress.[2,9,10] A study conducted in an internal medicine intensive care unit (ICU) indicated that alarms sounded an average of 6.07 times per hour and that alarms were active for 3.28 minutes of every hour. Of these alarms, 23% were valid, 36% were false, and 41% were ignored.[11] If clinical alarm systems are not properly managed, their adverse effects can put patient safety at serious risk.[9] From June 2009 through June 2012, the Joint Commission received 98 alarm-related event reports. Of those incidents, 80 resulted in patient death, 13 resulted in permanent loss of function, and 5 resulted in additional care or an extended hospital stay.[2,12]

In Turkey, little information is available on the frequency with which clinical devices in ICUs emit alarms or what percentage of those alarms are valid. It is also not known how sensitive nurses are to these alarms. Therefore, this study was conducted to examine the number and types of clinical device alarms used in medical and surgical ICUs, the duration of their activation, and nurses' degree of sensitivity to them.