Monitoring devices among ICU patients set off 2.5 million alarms in one month at UCSF Medical Center, a new study of “alarm fatigue” shows.

That included more than 1.1 million alarms about heart rhythm problems, of which nearly 89 percent were false alarms caused by computer algorithm errors.

“Nurses and patients are barraged by a staggering number of monitor alarms that could be resolved by improved computer algorithms,” said study senior author Barbara Drew, of UCSF. “Our results shed light on the high prevalence of alarms that are mostly false and provide insights into the causes of so many false alarms, along with suggestions for device improvement.”