UCSF

Background: While continuous electrocardiographic (ECG) monitoring in the Intensive Care Unit (ICU) is an important assessment device, technical alarms (i.e., artifact, arrhythmia suspend, and leads off) are frequent and can contribute to alarm fatigue in nurses. For example, we found that of >2.5 million total alarms generated during a one month period, 30% were technical alarms. Purpose: Examine the number and type of technical alarms (described below) and demographic and clinical factors associated with these alarms. Methods: Secondary analysis in 456 consecutive ICU patients with 48,173 hours of continuous ECG monitoring. Technical alarms examined: (1) artifact (noisy signal); (2) ECG leads off/fail (no ECG signal); and (3) arrhythmia suspend (no arrhythmia detection [software off] due to sustained artifact >20 seconds in the prior 30 seconds). Demographics (age, gender, race), ICU type (cardiac, medical/surgical, or neurological), clinical characteristics hypothesized to increase technical alarms (BMI, current smoker, cognitive impairment, tremor) and mechanical ventilation were obtained from the electronic health record. A negative binomial GLM regression model was used to evaluate both univariate and multivariate associations. Results: Among the 456 adult ICU patients, 208 (46%) were female and the mean age (years) was 60 + 17. Admitting ICU was as follows: 18% cardiac (n=83), 39% medical/surgical (n=180), and 43% neurological (n=198). Mean ICU length of stay was 98.54 hours (+121). Mean BMI was 28.1 + 8; 69 (15%) were current smokers; 195 (43%) had cognitive impairment; 35 (8%) had a tremor and 170 (39%) were treated with mechanical ventilation. There was a total of 572,763 technical alarms, 557,018 artifact (97.3%), 3,378 arrhythmia suspend (0.59%) and 12,367 ECG leads fail (2.2%). Fifty-eight percent of artifact alarms, and more than 60% of arrhythmia suspend and ECG leads fail alarms were two seconds in duration. Patients who were current smokers at admission wereiv more likely to have artifact and arrhythmia suspend alarms (p<0.018). Having a tremor was associated with all three types of technical alarms (p<0.001). Documented cognitive impairment was associated with arrhythmia suspend and ECG leads fail alarms (p<0.018). Being treated with mechanical ventilation was associated with fewer alarms for all three types of technical alarms (p=0.047). There was an association between being Native Hawaiian/Pacific Islander and experiencing ECG lead fail alarms (p=0.039). Conclusions/Implications for Practice: The vast majority of technical alarms were for artifact. Arrythmia suspend (software off) due to sustained artifact was uncommon. However, the mean time patients were in this technical alarm condition was 10 minutes, which in ICU patients could be clinically significant. Individual alarms lasted only seconds, which suggests that technical alarms are too sensitive and should be re- designed with a delay (e.g., 5 minutes) before alarming. Patients who were current smokers at admission were more likely to have artifact and arrhythmia suspend alarms. Having a tremor was associated with all three types of technical alarms. Documented cognitive impairment was associated with arrhythmia suspend and ECG leads fail alarms. Whereas, being treated with mechanical ventilation was protective (fewer alarms) for all three types of technical alarms. Patients with these features may require more guided alarm management strategies.