The dark side of Epi Pens

May 18, 2010

The Journal of Allergy and Clinical Immunology is probably not on the “must read” list for most of the wilderness medicine crowd, but an article in the current issue (2010; 125:419-423) merits careful study. This report queried two databases, the American Association of Poison Control Centers and the Food and Drug Administration’s Adverse Event Reporting System, to determine whether there has been a significant number of unintentional injections from these devices.

This is not a trivial question. With increasing recognition of the severe allergic reaction called “anaphylaxis”, physicians have been prescribing automated epinephrine injectors (“Epi Pens”) to many patients so that they can begin emergency treatment themselves after an unanticipated exposure to an allergic trigger. Having at risk individuals (or the parents/caretakers of at risk children) being trained and carrying Epi Pens is an important component of good health care, and should continue to be encouraged. As Epi Pens become more and more common, however, it is important to study whether there have been any unintended consequences of this availablity.

The answer from this study is an unequivocal “yes”. Over the thirteen year period spanning 1994 to 2007, there were 15,190 reports of unintentional injections from automated epinephrine injectors. You read that number correctly–over fifteen thousand. These numbers are trending upward, with more than half occuring in the last four years. The nature of these reports was such that fine details of the incidents were not available, although nearly a third of them required evaluation in a hospital or other health care setting. We know from other published reports that very severe complications have been reported from such inadvertent administration, including the need for amputations.

How do these incidents occur? Again, the detail in the study is not exhaustive, but included were accidental firing, mishaps during training, and accidental injection while reaching into a bag or purse.

Why should this matter in the wilderness or outdoor recreation industry? Most of us have had or will have the experience of a participant with a history of insect anaphylaxis coming to a program with a personal Epi Pen. The standard of care here is pretty straightforward in such a situation. Be aware of the specifics and where the client is keeping the device (a second device in the backcountry setting is appropriate); practice primary prevention by assiduously working to avoid exposures to the offending antigens; in the event of an actual exposure, assist the client in locating and using his device. In the event that the client is incapacitated and unable to activate her injector, be prepared to do so. Since the vast majority of outdoor professionals do not handle needles on a regular basis, be extremely careful not to become counted in a series of inadvertant administrations!

I wish that the whole thing were as simple as this. Sadly, it is not. For reasons that I do not understand, there has been a push by many in the outdoor/wilderness education community to encourage the wider availability of Epi Pens, beyond their intended prescription to patients with a medical diagnosis of susceptibility to anaphylaxis for their personal use. Some have opined that Epi Pens should become part of the regular first aid supplies for backcountry treks, challenge courses, and similar programs. The outdoor educator (presumably with the imprimatur provided by WFR or similar certification), would then be empowered to make the diagnosis of anaphylaxis in someone with no previous diagnosis, and provide an injection of epinephrine. Some in the WFR community have even been advocating for changes in law to permit this practice, believing that not doing so may be dooming some unfortunate participant in one of our programs to needless death. How could anyone object?

I’ll tell you how.

First of all, let’s put this problem into perspective. Although the data are a bit soft, the number of individuals in the US dying annually from anaphylaxis caused by insect (mostly Hymenoptera) stings is about 100. About the same number die from lightening, and twice as many die in floods each year. The risk of dying from food poisoning in the US is fifty-times that of insect anaphylaxis and the flu kills between 300 and 400 times as many individuals. So…. While it is obviously a devastating problem when it happens, it is extraordinarily rare and pales in comparison to a host of daily threats to life and limb. I have yet to hear of a well-documented death from insect anaphylaxis in the back country–I don’t deny that it may have happened to someone, somewhere; I simply have seen no convincing evidence of it. Yet, despite this rarity, folks seem to believe it necessary and appropriate for any backcountry trek to be “protected” by the presence of an Epi Pen and someone willing to employ it.

Other than the documented risk of accidental injury from the device, could anyone be injured by “intentional misuse”? In other words, could any harm come to someone with a breathing problem other than anaphylaxis to whom a well-intentioned layperson administered epinephrine?

You bet it could.

The problems which can result in sudden “breathing emergencies” are numerous, and include things like choking/aspiration, acute pulmonary edema, asthma, pneumonia/pneumonitis, primary cardiac disease, dehydration/acidosis, anxiety, and many more. While those of us who deal with such things on a daily basis can generally pick up on the nuances which distinguish some of these from others, this is not easy for someone who is not regularly assessing such patients. Regardless of cause, breathing emergencies tend to be very dramatic and, frankly, scary. Being suddenly confronted with someone gasping, short of breath, and severely panicked can be terrifying to the uninitiated–and an hour or two of classroom instruction hardly qualifies as “initiation”. In such a setting, the tendency to “do something” is powerful, and if an Epi Pen is readily available, it may well be used. If the problem is not anaphylaxis (or, perhaps, asthma), the drug will either do nothing or make things much worse. In particular, an anxiety reaction (which can produce dramatic respiratory symptoms) will be severely worsened by the administration of epinephrine.

Carrying Epi Pens has now been shown to entail a real risk of injury. Using them inappropriately can significantly worsen a number of conditions which could be confused with anaphylaxis. Fatalities from insect-related anaphylaxis are extraordinarily rare. In light of these facts, it is inexplicable that outdoor educators continue to fret so much about the need for them to have ready access to these devices. It is hard to see this preoccupation as a sincere, informed desire to improve health and save lives. If that were the motivation, I would expect to see a lot more attention being devoted to things like pre-trek influenza immunization or expedition food safety–serious health issues which are vastly more common than anaphylaxis.

Of course, it is cool to carry an injectable drug in one’s backcountry first aid kit!