Conventional wisdom has always been to "count to ten" when administering an epinephrine autoinjector, so as to allow the medication enough time to be adequately delivered into the muscle.However, in practice, ten seconds can seem like an eternity when attempting to hold a little one still. Many parents worry that if they don't follow the "ten second rule", their squirmy kid will not receive enough life-saving medication to avert an allergic disaster.
Well, here's some good news: a recent study evaluating various EpiPen injection times has determined that even with an injection time as short as 1 second, over 95% of epinephrine was absorbed into muscle. (Baker TW, Webber CM, Stolfi A, Gonzalez-Reyes E: The TEN study: time epinephrine needs to reach muscle. Ann Allergy Asthma Immunol. 2011;107:235-238.)
No little children were used as pincushions in the course of this study. Instead, the researchers used marbelized beef as a proxy for human thigh muscle, and measured the amount of epinephrine delivered using a very precise scale.
Take home message?
Epinephrine autoinjectors are designed to be relatively forgiving of discrepancies in technique. The important thing isn't that you use them perfectly -- it's that you USE THEM.