Consider Body Weight When Using an Epinephrine Injector

EpiPen Injector

When a person experiences anaphylaxis, a life threatening reaction to foods, bees, latex or other causes, the best course of action is to administer epinephrine quickly and effectively. Typically, this means using an epinephrine auto-injector (like an EpiPen or Auvi-Q) and injecting into the side of the upper leg.

A recent study conducted in the U.K. found that the injection site may vary depending upon body weight. Using ultrasound to take skin surface to muscle depth measurements, researchers found that higher weight and waist circumference were linked to a skin surface to muscle depth measurement greater than the length of the auto-injector needle. This means the epinephrine was not getting into the muscle where it would be more rapidly absorbed.

The study concluded that it may be beneficial to inject further down the leg where skin surface to muscle depth surpassed the length of the auto-injector needle for a majority of kids. 

Auvi-Q Auto Injector

Talk to your doctor (and share the press release, Injecting Epinephrine into the Lower Rather Than Upper Thigh May Be More Effective in Overweight Children) if you have concerns about weight and the effectiveness of an epinephrine injector. Make sure that the prescribed auto-injector user and all caregivers are aware of the best place to administer the injection to maximize the benefits of the medication.

Best Advice From an Allergist and Immunologist Specialist

Epinephrine

"Use epinephrine early and often," was the message from Dr. John Oppenheimer, an allergist and immunologist from UMDNJ. I recently had the pleasure of hearing Dr. Oppenheimer speak and I was struck by a story he shared. He told us that his wife asked him why he often shouts into the phone, "Use it! Use it now!" That's the urgent plea from Dr. Oppenheimer when a parent or school nurse calls his on-call service wondering if they should use an epinephrine auto-injector for someone they suspect may be having an allergic reaction.  

"Use it" means "administer epinephrine now".

I've been there. When my child has said, "My mouth feels itchy", or "I'm getting a hive on my lip," I've grabbed the bottle of Benadryl in one hand and the epinephrine in the other and watched closely. Who wants to stick a needle in a child and call an ambulance unless it's absolutely necessary?

According to Dr. Oppenheimer, use of epinephrine early in the anaphylaxis state may diminish the effect of late-stage anaphylaxis. He said that anaphylaxis is under-diagnosed and under-treated and he made it clear that the first line of defense is epinephrine, not an antihistamine, when an anaphylactic reaction is starting.

He shared that the triggers for anaphylaxis are Food (33% of the time), Unknown (25%), Insect (19%), Medications (14%), Other (9%, includes cat dander, latex, cleaning agents, etc.). 

For me, Dr. Oppenheimer's talk was another good reminder. One quarter of the time, an anaphylactic reaction has an unknown cause. An antihistamine is not effective at halting anaphylaxis. While no one wants to use an epinephrine injector, it is our best defense against anaphylaxis.

It is comforting to be able to reach an on-call doc in a moment of uncertainty and panic. Call your doctor if you have the time. If not, talk to your doctor now, so you have a plan in place if an anaphylactic reaction occurs. 

Food Allergic Should Have Double Dose of Epinepherine Available

So the latest recommendation is that people with food allergies should be carrying two doses of their life-saving epinephrine. This is the conclusion of researchers at Children's Hospital Boston after a six year study. Dr. Rudders headed the study and says, "Until we're able to clearly define the risk factors for the most severe reactions, the safest thing may be to have all children at risk for food-related anaphylaxis carry two doses of epinephrine".

It was also discovered during the course of this research that many emergency rooms are treating food allergy reactions with antihistamines and steroids, rather than epinephrine. Rudders explains that "these findings may be due to lack of a universal understanding of anaphylaxis in the ED (emergency department) before 2006". She goes on to say that she hopes her study will move things forward in this area.

The entire study was written up in the April 2010 journal of Pediatrics.