Are melodic medical equipment alarms easily learned?

We tested melodic auditory alarms recommended in the IEC 60601-1-8 standard for medical electrical equipment for ease of learning and discrimination, and for effectiveness during a timeshared task.

Twenty-two critical care nurses learned the IEC 60601-1-8 melodic alarms over two training sessions more than a week apart, with or without mnemonics suggested in the standard. Subsequently, the nurses identified alarms arriving at quasi random intervals while performing a timeshared arithmetic task.

Only one nurse (4.5%) identified the alarms with 100% accuracy after two training sessions. Mnemonics did not improve overall alarm identification accuracy (mnemonic = 56%, nonmnemonic = 55%) but led to a narrower range of confusions between alarms. Nurses responded faster (P < 0.0001) and more accurately (P = 0.032) to medium priority than high priority alarms, despite rating high priority alarms as sounding more urgent (P < 0.0001). Nurses with at least 1 yr of formal musical training identified the alarms much more accurately (musical training = 73%, no musical training = 38%, P < 0.0001), perceived a greater distinction between high and medium priority alarms (P = 0.002), and found identifying the alarms easier overall (P = 0.023). During the timeshared task, nurses' responses were slower (P = 0.002) and became less accurate (P = 0.02).

The slow rate of learning and persistent confusions suggest that the IEC 60601-1-8 melodic alarms should be redesigned before they are adopted for clinical practice.