A study comparing the usability of fully automatic versus semi-automatic defibrillation by untrained nursing students

Current international guidelines prefer the use of semi-automatic external defibrillators (SAEDs) over fully automatic external defibrillators (FAEDs). However, there is a lack of evidence supporting this recommendation. We conducted a study of usability with nursing students comparing the FAED version against the SAED version of the Lifepak CR Plus AED (Medtronic, Redmond, USA). We hypothesized that FAED use would limit the number of operator-device interactions, thereby increasing compliance by the rescuer, safety and speed.

Sixty-two untrained first year nursing students were randomized to use the FAED or the SAED in a simulated cardiac arrest scenario. During analysis and delivery of three shocks, the AED guided the user with six voice prompts per shock (18 voice prompts per student). Their performance with regard to efficacy and safety was assessed using video recording.

All rescuers except for two were able to attach electrodes and deliver a series of three shocks. During rhythm analysis by the device, FAED users made 30/372 (8%) errors against 62/360 (17%) errors for SAED users (P < 0.001). During shock delivery, FAED users made 0/186 errors against 12/180 (7%) for SAED users (P < 0.001). FAED use eliminated long time intervals between the first to the third shock (range 47-49s for FAED versus 41-90s for SAED).

Despite a lack of BLS skills and AED training, the majority of students demonstrated safe and effective use of the AED. The use of the FAED version of the CR Plus resulted in increased compliance with the protocol and reduced variability in time to deliver three shocks. Further research is needed to confirm these findings in other groups of first responders.