In this prospective study, researchers conducted direct observations in one urban, academic Emergency Department (ED) to determine whether and which ED monitor alarms led to observable changes in patients’ care. During 53 hours of observation, there were 1,049 alarms associated with 146 patients, resulting in clinical management changes in 5 patients. Researchers observed that staff did not observably respond to nearly two-thirds of alarms, which may be a sign of alarm fatigue.