A randomized maternal evaluation of epinephrine autoinjection devices

Background: Intramuscular epinephrine (adrenaline) is the first-line therapy for anaphylaxis and prompt administration improves outcome. In 2011, two epinephrine autoinjectors existed in the United Kingdom, differing in their users' administration method: EpiPen(®) and Anapen(®) . We routinely train all families who receive these devices.

Aim: To evaluate: Maternal competence in using epinephrine autoinjectors following our standard anaphylaxis training package. Which device mothers found easier to use.

Methods: Mothers with no previous epinephrine autoinjector experience were approached to participate. One clinician provided a standardized demonstration on using a randomly assigned autoinjector device. She immediately evaluated the mothers' performance using ten predetermined criteria. Four criteria were device specific and six were common criteria to both devices.

Results: One hundred mothers participated: 50 EpiPen(®) and 50 Anapen(®) . A substantial proportion of mothers (15% overall) were not able to successfully 'fire' these training devices: Anapen(®) 4% and EpiPen(®) 26% (OR 8.43, p = 0.005). Only 22% of mothers overall were able to perform all ten procedures completely successfully: Anapen(®) 32% and EpiPen(®) 12%. Chi-squared analysis showed a significantly higher proportion of mothers correctly performing all Anapen(®) specific procedures than EpiPen(®) (OR 14.24, p < 0.0001).

Conclusion: It is concerning that 15% of mothers overall could not 'fire' these devices correctly despite a one-to-one demonstration, identifying a need for more user friendly devices and training. Mothers found the Anapen(®) device significantly easier to use, which may have implications for future prescribing. Evaluation of the next generation of autoinjectors and their training packages needs to be performed as important practical differences may be found.