The crying wolf: still crying?

Roland Fried, PhD† In 1994, Lawless compared the situation of alarms in the intensive care unit (ICU) with the boy who cried wolf in the famous fable by Aesop, alluding to the danger of desensitization of caregivers to true medical device alarms through the overwhelming number of false medical device alarms that he observed on a pediatric ICU. Alarm limits may be set dangerously broad, or alarms may even be completely disabled to reduce the nuisance from false alarms. Even at these settings, clinicians may tolerate an alarm for up to 10 min before taking action. This situation cries for immediate remedy. The sad reality, although, is that not much seems to have changed over the nearly 15 yr since Lawless’ publication. The current literature and ongoing research efforts (reviewed in Ref. 6) as well as recent data from our own group, show that still the vast majority of medical device alarms are false positives. Interestingly, there is no scarcity of research addressing the problem of medical device alarms. Many different approaches have been studied in the fields of statistics and artificial intelligence as well as biomedical and human factors engineering. Several approaches have shown efficacy and effectiveness in reducing the rate of false alarms in clinical study. Still, very little has been implemented in commercially available medical devices. In this situation Görges et al. promise hope in their article published in this issue of Anesthesia & Analgesia. In their study, they first acquired comprehensive clinical data on medical device alarms and then investigated two approaches to reduce the number of false-positive alarms. The authors must be commended for their efforts, as we know from other researchers and our own experience how much stamina it takes to acquire alarm data and consistently annotate sufficiently large numbers of medical device alarms. Görges et al. confirm that only the minority of medical device alarms are clinically relevant—in their study, 23% of all alarms. They also found that not only were six alarms activated per hour per bed, but also alarms were sounding 31⁄2 min per hour per bed. Extrapolating to a 10-bed ICU, this means that a false alarm is active, i.e., making some noise or “crying,” nearly 50% of the time, day and night, 24/7. These numbers are in line with other studies. If we keep in mind that it took the boy in Aesop’s fable only two false alarms to make the shepherds ignore the third but true and deadly alarm, the current situation of medical device alarms seems mindboggling. Of course, the study by Görges et al. has distinct weaknesses, most of which the authors diligently discuss: night shifts were not included in the study, the physical presence of the observer may have induced a Hawthorne effect, clinical annotations of alarms were subjective, and there may have been significant intraand interobserver variability. Moreover, clinical practice patterns in the study ICU may differ from other institutions, which may further affect the generalizability of the reported results, as may the differences in annotation schemata between different studies, as pointed out by the authors. But this is true for each and every clinical alarm study published as of today. And still, all studies come to similar conclusions despite their differences in methodology and clinical settings, actually strengthening rather than weakening our point about the inadequacy of current device alarms. From the *Department for Medical Informatics, Biometrics and Epidemiology, Ruhr-University, Bochum, Germany; and †Department of Statistics, Technical University Dortmund, Dortmund, Germany. Accepted for publication January 19, 2009. M.I. and R.F. have received research grants from the German Research Foundation (DFG SFB475). MI has received consulting fees from Draeger Medical and is managing member of Boston MedTech Advisors Europe. Address correspondence and reprint requests to Dr. Michael Imhoff, Am Pastorenwäldchen 2, D-44229 Dortmund, Germany. Address e-mail to mike@imhoff.de. Copyright © 2009 International Anesthesia Research Society