For several years, I wrote a regular column for the magazine of the Adirondack Mountain Club, Adirondac. They were having some financial challenges which caused their page allotment to shrink, so the column has been on hiatus.
The editor has asked me to resume the column in the summer, and I am doing so. As in the past, it will provide advice on the health and safety aspects of outdoor recreation, targeting a lay audience. The initial column will discuss some aspects of canoe safety. The Adirondack Mountain Club does not as yet have an online version of the magazine, but I will post the columns in the Publication area of my website.
Saturday, February 26, 2011
Thursday, January 6, 2011
Best Giardia Story Ever
A buddy of mine who works as a college outdoor education instructor recently shared an experience with me. For reasons I will mention later, today is an amazingly appropriate day to bring this up.
My friend related a visit to one of the college's treks by a student instructor from the west. The visitor was appalled to learn that this particular program did not practice universal water treatment during their expeditions. When told that the local instructors had carefully considered things and no longer recommended routine treatment of most Adirondack waters, he commented that it must be because of something unique to New York, since tasting even a drop of untreated water in the American west was "guaranteed" to result in giardiasis. He went on with a litany of reasons why this was to be avoided at all costs, not the least being that giardiasis was essentially incurable, and that those unfortunate enough to acquire it would have it forever--often flaring up any time an offending food was consumed. He treated everything he drank on the trek. No one else did. Everyone was just fine.
Of course, everything about this would be simply silly if it were not for the fact that the person involved is en route to becoming a professional outdoor educator, presumably about to share such nonsense with unsuspecting students. This is hardly a "controversy" anymore; it is difficult to identify any true expert in this field who considers the "treat everything" approach to be necessary or appropriate. Which brings me to the reason why today is a very good time to tell this tale.
A report today (http://www.nytimes.com/aponline/2011/01/05/health/AP-EU-MED-Autism-Fraud.html?_r=2&ref=health) has confirmed once and for all that the original study linking vaccines to autism was not only incorrect, it was fraudulent. The 1998 study, by a British quack named Andrew Wakefield, reported 12 reportedly normal children in whom autism developed as a consequence of the MMR vaccine. The journal in which it was published retracted it long ago because of concerns about its validity, and all of Wakefield's coauthors disassociated themselves with its conclusions. Literally scores of well-designed studies involving thousands of children have been published subsequently, none of which have supported the Wakefield hypothesis. One would think that the concern would have gone away by now.
Sadly, things didn't work out that way. In the nearly 13 years since the Wakefield publication, concern about the MMR vaccine became rampant, leading many families to avoid it. This, in turn, has resulted in a resurgence of measles in the world, with countless preventable deaths. Nonetheless, uninformed "experts" have continued to trump this bogus association, believing a study of 12 patients over well-designed trials with thousands.
Believe it or not, this situation is nearly identical to the current infatuation of some wilderness folks with water-borne giardiasis.
There has been exactly one peer-reviewed scientific study suggesting a link between wilderness water consumption and giardiasis. This report, from 1976, reported that about 2/3 of participants in a camping trip in Utah's Uinta mountains acquired giardiasis. The authors ascribed the outbreak to consumption of surface water.
In subsequent years, it has become clear this this report was incorrect (although certainly not fraudulent--just wrong). Analyzing this incident in light of contemporary knowledge about giardiasis has made it clear that this was an epidemic of food- or hand-to-mouth borne infection. (This is discussed in more detail in a paper available on my website: http://adirondoc.com/publications/water_quality_2004.pdf).
Although no subsequent scientific studies have shown any association between North American wilderness water consumption and giardiasis (or, indeed, any infection), the damage was done with the single 1976 paper, just as it was with Wakefield's 1998 autism/vaccine study. "True believers" such as the student instructor continue to tout misinformation which has been long-since discredited--often embellishing it along the way.
While the damage done by this over 30 year old paper pales in comparison to that of the Wakefield study (I doubt that anyone has died because of it!), it certainly has had negative effects. Most strikingly, the incessant attention to water quality in the backcountry has eclipsed attention to a much more important strategy--hand washing---which probably would have prevented the Utah outbreak! It has created the market for a dizzying array of technologic fixes (filters, "steri-pens", etc) which exist to solve a problem which doesn't exist. It has perpetuated very bad science among folks who aspire to professional careers in outdoor education.
I'll conclude with a "stay tuned". With a couple of colleagues and a student, I am analyzing data from a series of studies we have done examining the colonization of backpackers' hands with (hope you're not eating lunch now) organisms found in FECES. Without giving away the results, let me just suggest that you avoid shaking hands with folks you meet in the wilderness...
My friend related a visit to one of the college's treks by a student instructor from the west. The visitor was appalled to learn that this particular program did not practice universal water treatment during their expeditions. When told that the local instructors had carefully considered things and no longer recommended routine treatment of most Adirondack waters, he commented that it must be because of something unique to New York, since tasting even a drop of untreated water in the American west was "guaranteed" to result in giardiasis. He went on with a litany of reasons why this was to be avoided at all costs, not the least being that giardiasis was essentially incurable, and that those unfortunate enough to acquire it would have it forever--often flaring up any time an offending food was consumed. He treated everything he drank on the trek. No one else did. Everyone was just fine.
Of course, everything about this would be simply silly if it were not for the fact that the person involved is en route to becoming a professional outdoor educator, presumably about to share such nonsense with unsuspecting students. This is hardly a "controversy" anymore; it is difficult to identify any true expert in this field who considers the "treat everything" approach to be necessary or appropriate. Which brings me to the reason why today is a very good time to tell this tale.
A report today (http://www.nytimes.com/aponline/2011/01/05/health/AP-EU-MED-Autism-Fraud.html?_r=2&ref=health) has confirmed once and for all that the original study linking vaccines to autism was not only incorrect, it was fraudulent. The 1998 study, by a British quack named Andrew Wakefield, reported 12 reportedly normal children in whom autism developed as a consequence of the MMR vaccine. The journal in which it was published retracted it long ago because of concerns about its validity, and all of Wakefield's coauthors disassociated themselves with its conclusions. Literally scores of well-designed studies involving thousands of children have been published subsequently, none of which have supported the Wakefield hypothesis. One would think that the concern would have gone away by now.
Sadly, things didn't work out that way. In the nearly 13 years since the Wakefield publication, concern about the MMR vaccine became rampant, leading many families to avoid it. This, in turn, has resulted in a resurgence of measles in the world, with countless preventable deaths. Nonetheless, uninformed "experts" have continued to trump this bogus association, believing a study of 12 patients over well-designed trials with thousands.
Believe it or not, this situation is nearly identical to the current infatuation of some wilderness folks with water-borne giardiasis.
There has been exactly one peer-reviewed scientific study suggesting a link between wilderness water consumption and giardiasis. This report, from 1976, reported that about 2/3 of participants in a camping trip in Utah's Uinta mountains acquired giardiasis. The authors ascribed the outbreak to consumption of surface water.
In subsequent years, it has become clear this this report was incorrect (although certainly not fraudulent--just wrong). Analyzing this incident in light of contemporary knowledge about giardiasis has made it clear that this was an epidemic of food- or hand-to-mouth borne infection. (This is discussed in more detail in a paper available on my website: http://adirondoc.com/publications/water_quality_2004.pdf).
Although no subsequent scientific studies have shown any association between North American wilderness water consumption and giardiasis (or, indeed, any infection), the damage was done with the single 1976 paper, just as it was with Wakefield's 1998 autism/vaccine study. "True believers" such as the student instructor continue to tout misinformation which has been long-since discredited--often embellishing it along the way.
While the damage done by this over 30 year old paper pales in comparison to that of the Wakefield study (I doubt that anyone has died because of it!), it certainly has had negative effects. Most strikingly, the incessant attention to water quality in the backcountry has eclipsed attention to a much more important strategy--hand washing---which probably would have prevented the Utah outbreak! It has created the market for a dizzying array of technologic fixes (filters, "steri-pens", etc) which exist to solve a problem which doesn't exist. It has perpetuated very bad science among folks who aspire to professional careers in outdoor education.
I'll conclude with a "stay tuned". With a couple of colleagues and a student, I am analyzing data from a series of studies we have done examining the colonization of backpackers' hands with (hope you're not eating lunch now) organisms found in FECES. Without giving away the results, let me just suggest that you avoid shaking hands with folks you meet in the wilderness...
Thursday, December 2, 2010
Why mosquitos love us and hate DEET
It's hard to be thinking about mosquitos during the first lake effect event of the season, but maybe it will get you into the mood for summer!
For a long time, I have endorsed the usual understanding of the mechanism by which mosquitos target warm-blooded animals. For quite a while, it has been recognized that there is a complex neurochemical mechanism by which the bugs are attracted to carbon dioxide. From an evolutionary standpoint, this makes a lot of sense: if you are looking for a blood meal, what better way to find it than by going after something which breathes out carbon dioxide? It is also consistent with our backcountry observations. How many times, for example, have you noticed the propensity of these creatures to congregate under the tent fly?
This understanding has also permitted me to pooh-pooh students in my classes who claim that something about their own sweat, soap, or BO is particularly attractive to mosquitos. I have generally dismissed them as whiners, and pontificated that there was no biologic mechanism for such an observation. How could a bug distinguish between Dr. Bronner's and Mountain Suds?
Mea culpa.
Complex modern science has now shown us that the smell detection system of mosquitos is vastly more complicated than we ever could have imagined. In the process, it has also uncovered the biologic explanation for the effectiveness of DEET. Pretty impressive.
The study (by Liu and associates at Vanderbilt) is available online from the journal PLoS Biology (http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1000467). The molecular biology here is daunting, and not for the faint of heart. Also keep in mind that the work was done with an African mosquito; it is certainly plausible, however, that similar mechanisms are in place for other species.
These scientists have unraveled the existence of two distinct olfactory signaling pathways in these insects. Each of these pathways (AgOR and AgIR) consists of a family of specific receptors, each of which, presumably, can respond to specific odors. Such responses can be either attractive or repulsive. A specific receptor (AgOR7) appears to be the actual target of DEET; animals in whom this receptor was inactivated by microinjection of specific RNA fragments were no longer affected by DEET.
What can we take away from this elegant science? Carbon dioxide is still a potent attractant for mosquitos, but short of stopping breathing there is nothing we can do about it. DEET works--we know this from a lot of previous behavioral studies, and now we understand it at the molecular level. From a wealth of other studies, we also know that the health concerns of DEET are vastly overblown and can generally be ignored. Mosquitos also seem to be capable of responding to a lot of other olfactory stimuli, but we do not as yet understand what makes something attractive or repulsive.
Bottom line--it is now plausible that certain individuals are more attractive to mosquitos than others. Other than DEET and protective garmets, however, there is little to do other than sucking it up!
For a long time, I have endorsed the usual understanding of the mechanism by which mosquitos target warm-blooded animals. For quite a while, it has been recognized that there is a complex neurochemical mechanism by which the bugs are attracted to carbon dioxide. From an evolutionary standpoint, this makes a lot of sense: if you are looking for a blood meal, what better way to find it than by going after something which breathes out carbon dioxide? It is also consistent with our backcountry observations. How many times, for example, have you noticed the propensity of these creatures to congregate under the tent fly?
This understanding has also permitted me to pooh-pooh students in my classes who claim that something about their own sweat, soap, or BO is particularly attractive to mosquitos. I have generally dismissed them as whiners, and pontificated that there was no biologic mechanism for such an observation. How could a bug distinguish between Dr. Bronner's and Mountain Suds?
Mea culpa.
Complex modern science has now shown us that the smell detection system of mosquitos is vastly more complicated than we ever could have imagined. In the process, it has also uncovered the biologic explanation for the effectiveness of DEET. Pretty impressive.
The study (by Liu and associates at Vanderbilt) is available online from the journal PLoS Biology (http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1000467). The molecular biology here is daunting, and not for the faint of heart. Also keep in mind that the work was done with an African mosquito; it is certainly plausible, however, that similar mechanisms are in place for other species.
These scientists have unraveled the existence of two distinct olfactory signaling pathways in these insects. Each of these pathways (AgOR and AgIR) consists of a family of specific receptors, each of which, presumably, can respond to specific odors. Such responses can be either attractive or repulsive. A specific receptor (AgOR7) appears to be the actual target of DEET; animals in whom this receptor was inactivated by microinjection of specific RNA fragments were no longer affected by DEET.
What can we take away from this elegant science? Carbon dioxide is still a potent attractant for mosquitos, but short of stopping breathing there is nothing we can do about it. DEET works--we know this from a lot of previous behavioral studies, and now we understand it at the molecular level. From a wealth of other studies, we also know that the health concerns of DEET are vastly overblown and can generally be ignored. Mosquitos also seem to be capable of responding to a lot of other olfactory stimuli, but we do not as yet understand what makes something attractive or repulsive.
Bottom line--it is now plausible that certain individuals are more attractive to mosquitos than others. Other than DEET and protective garmets, however, there is little to do other than sucking it up!
Wednesday, October 13, 2010
How much "risk" can we tolerate in the wilderness?
This topic comes up a lot among wilderness educators, but I recently came across two seemingly unrelated pieces in the New York Times which provide a very nice context to the discussion.
The first (http://www.nytimes.com/2010/08/27/us/27cuts.html?_r=1&scp=3&sq=fire%20departments&st=cse) describes the angst which is developing in a number of urban areas as budget constraints are challenging city fire and EMS services. The article begins with the tragic story of a two-year-old boy in San Diego who suffered a fatal aspiration at his home. Although there was a fire station near the home, staffing changes in the SDFD led to its being empty at the time of the incident. The police responded to the child's home within five minutes and started CPR, but it took 9 and a half minutes for an ambulance to arrive. The child was pronounced dead at the hospital.
The first (http://www.nytimes.com/2010/08/27/us/27cuts.html?_r=1&scp=3&sq=fire%20departments&st=cse) describes the angst which is developing in a number of urban areas as budget constraints are challenging city fire and EMS services. The article begins with the tragic story of a two-year-old boy in San Diego who suffered a fatal aspiration at his home. Although there was a fire station near the home, staffing changes in the SDFD led to its being empty at the time of the incident. The police responded to the child's home within five minutes and started CPR, but it took 9 and a half minutes for an ambulance to arrive. The child was pronounced dead at the hospital.
Although it is not clear to me that the child would have survived with earlier care (when children survive such incidents, it is almost always because of immediate bystander intervention), the implication of the article was that harm may have been done because the city could not meet up to the "national goal" of a five minute response.
Well, just a minute here.
I am writing this entry at our summer home in the Adirondacks. I probably couldn't get my nearest neighbor here within five minutes. The nearest fire department with EMS service is in a town about 16 miles away, and that is a volunteer operation. Ten times the "national goal" would actually be a pretty good response to our place!
Mind you, this area is by no means "wilderness". There are several hundred homes in the vicinity, with such important services as bars, a gas station, pizza joints, and even a (limited hours) vet clinic. Although we are seasonal users, there are plenty of year-round residents. If any of my neighbors are disturbed that our access to emergency medical services is way outside the national goal, I haven't heard it from them. Indeed, nearly every edition of the local weekly (we also have a paper) carries a letter to the editor thanking the volunteer ambulance crews for something!
Folks who choose to live (or get away) in places such as this generally make very informed decisions. No--we can't call a cab. No--we may not be able to have high-speed internet access. No--if the big one comes some evening, we will not be defibrillated within minutes. On the other hand, we are not awakened by sirens at night, the smells of balsam replace those of exhaust, and we don't worry about walking in the neighborhood. There are plenty of folks living throughout the US in very similar circumstances, and I doubt that many would trade them in order to be assured of a more rapid EMS response.
How does this apply to the wilderness? Just like the person who moves from San Diego, CA to Woodgate, NY is accepting a change in the availability of assistance in emergencies, the user of the wilderness is (or should be) doing so to an even greater degree. Stepping into the backcountry is an experience of inestimable value. It has a downside. The likelihood of surviving major trauma deep in the Five Ponds Wilderness is nil. An identical injury on 42nd Street and 8th Avenue might well be survivable. Sadly, one just can't have it both ways. Take your pick.
This ethic extends to situations well beyond major trauma. Sprain your ankle at the tennis club, and expect your buddy to drive you home and share a beer with you after helping you get some ice. Sprain it on the way down Katahdin and you should expect a pretty rough time; please don't expect a helicopter ride to Bangor. One of my many complaints about the "WFR" movement is that it may contribute to the perception that there is really something which can be done for devastating injury or illness is very remote areas. Usually, there isn't. Accept it.
Which brings me to the other article: http://www.nytimes.com/2010/08/27/opinion/27stroll.html?_r=1&scp=5&sq=wilderness&st=nyt.
This opinion piece, by an attorney, decries the US Forest Service for lack of signage in some wilderness areas, bemoaning the occasonal camper, hiker, or hunter who becomes lost. If one wishes to hike on established and well marked trails, the options in North America are nearly limitless. Yet, if one wants to test the extent of his navigational and wilderness skills in an expansive, truly "unmarked" environment, options in the lower 48 are not many. Indeed, when I teach such skills, I prefer to do so in Alaska. We do not seem to care that a number of skiers choosing black diamond routes will sustain serious, indeed some life-threatening injuries. Why can we not allow the wilderness equivalent of "black diamond" for those of us who desire such experiences?
Backpacking and similar wilderness pursuits, in virtually every database, are extraordinarily safe. Yet, they carry inherent risks which simply cannot be eliminated without significantly devaluing the experience. By giving the impression that we can "manage" these risks out of existence, we do harm in two ways. We provide expectations of safety which cannot be realized. We invite regulatory interventions which ultimately destroy the experiences that we value.
Monday, August 16, 2010
Wilderness Helicopter Evacuations
This has not been a good summer for the medical helicopter industry, or its employees and patients. Crashes in July took the lives of three in Arizona and two in Oklahoma; these brought to four the number of fatal medical helicopter crashes in 2010 alone.
Fortunately, none of these crashes involved wilderness rescues. On the other hand, it is simply a matter of time before a catastrophic incident occurs in the backcountry.
There has been a proliferation in the use of helicopters to provide medical response to wilderness injuries and illnesses in the past few years. Indeed, in this month alone, two such responses occured in the New York Adirondacks. While there may certainly be circumstances in which such an undertaking could be lifesaving, there are others in which this response has been mobilized for a condition which turned out to be trivial. Folks have undergone helicopter evacuations for sprained ankles, broken arms, and similar mishaps which in an earlier time would have been handled with an uncomfortable, but safer, "walk-out". The US Forest Service even dispatched a helicopter to "rescue" two workers who were freaked out by the sounds of wolves howling: http://www.mtexpress.com/index2.php?ID=2005112785
The Federal Aviation Administration has recently (June 8, 2010) recognized medical helicopters as an industry meriting closer regulation and scrutiny. Their fact sheet highlights (without explicitly addressing wilderness use) one of the vulnerabilities in the backcountry setting. The decision to mobilize a helicopter medical mission actually requires the decision of two professionals. First, a medical person (typically on the scene) makes the determination that air evacuation is necessary. Secondly, the pilot makes the determination that the mission is safe.
In urban settings, the first of these decisions is often (although not always) made by individuals with medical training and experience: EMTs, emergency physicians, etc. The system in the backcountry, however, is far less formal. The call for a helicopter rescue may well be initiated by an individual on the scene with minimal training and experience in the assessment of injuries. While one might argue that "when in doubt, err on the side of safety", the above experiences suggest that it is hardly a given that "safety" is served by dispatching a helicopter into wilderness terrain.
This is obviously a very controversial subject, and it currently is informed by very little data and lots of anecdote. With a colleague, I am currently embarking on a study of medical helicopter evacuations in a wilderness area which will include actual disposition of the evacuees--some of the anecdote to which I allude suggests that it is not uncommon for individuals flown out of the woods to be evaluated in the hospital and sent home without admission. When complete, the data from this study may help us develop a more structured process for mobilizing this high-tech and potentially deadly resource in the wilderness.
Fortunately, none of these crashes involved wilderness rescues. On the other hand, it is simply a matter of time before a catastrophic incident occurs in the backcountry.
There has been a proliferation in the use of helicopters to provide medical response to wilderness injuries and illnesses in the past few years. Indeed, in this month alone, two such responses occured in the New York Adirondacks. While there may certainly be circumstances in which such an undertaking could be lifesaving, there are others in which this response has been mobilized for a condition which turned out to be trivial. Folks have undergone helicopter evacuations for sprained ankles, broken arms, and similar mishaps which in an earlier time would have been handled with an uncomfortable, but safer, "walk-out". The US Forest Service even dispatched a helicopter to "rescue" two workers who were freaked out by the sounds of wolves howling: http://www.mtexpress.com/index2.php?ID=2005112785
The Federal Aviation Administration has recently (June 8, 2010) recognized medical helicopters as an industry meriting closer regulation and scrutiny. Their fact sheet highlights (without explicitly addressing wilderness use) one of the vulnerabilities in the backcountry setting. The decision to mobilize a helicopter medical mission actually requires the decision of two professionals. First, a medical person (typically on the scene) makes the determination that air evacuation is necessary. Secondly, the pilot makes the determination that the mission is safe.
In urban settings, the first of these decisions is often (although not always) made by individuals with medical training and experience: EMTs, emergency physicians, etc. The system in the backcountry, however, is far less formal. The call for a helicopter rescue may well be initiated by an individual on the scene with minimal training and experience in the assessment of injuries. While one might argue that "when in doubt, err on the side of safety", the above experiences suggest that it is hardly a given that "safety" is served by dispatching a helicopter into wilderness terrain.
This is obviously a very controversial subject, and it currently is informed by very little data and lots of anecdote. With a colleague, I am currently embarking on a study of medical helicopter evacuations in a wilderness area which will include actual disposition of the evacuees--some of the anecdote to which I allude suggests that it is not uncommon for individuals flown out of the woods to be evaluated in the hospital and sent home without admission. When complete, the data from this study may help us develop a more structured process for mobilizing this high-tech and potentially deadly resource in the wilderness.
Tuesday, May 18, 2010
The dark side of Epi Pens
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!
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!
Friday, May 7, 2010
Packs and Strokes
The health problems which confront backpackers are rarely consequential, and certainly less important than the overall very positive impact on health which spending time in the wilderness conveys. Every now and then, however, something potentially serious comes up. Ignoring signs of trouble in the front country can be dangerous, but the rapid availablity of emergency medical services may compensate for earlier delays. The back country, however, is far less forgiving.
I was reminded of this the other day, upon reading and responding to a question posed by a visitor to my website. This gentleman was on a hike in the northeast when he began to experience some tingling and weakness of one arm, accompanied by facial weakness and slurring of speech; fortunately, this resolved on its own over a few minutes. Nonetheless, he rightly worred about this, headed out, and spent some time in a hospital. In retrospect, he wondered if all of this could have been caused by too-tight backpack straps.
The quick answer to his question was "of course not". These sudden changes in his neurologic status could have represented a stroke; the fact that they resolved within minutes defined them as a "mini stroke" or transient ischemic attack (TIA). If it had been the start of an actual stroke, he would have had a very narrow time window of opportunity to receive a therapy which could prevent or minimize the develoment of long-term disability. In fact, this time window is so short I believe that a "walk out" evacuation (assuming the group is within an hour or so of a trail head and the individual is stable enough to walk) is preferable to staying put and sending for help.
The notion that this could have been caused by pack straps, however, is not unreasonable. I have written extensively about this in an article on this website. Go to the "publications" link and find the article curiously entitled "On numbness and tingling". Pressure of straps from a backpack on the nerves supplying the arms frequently causes numbness and tingling. This almost always occurs in both arms, however, and should never be accompanied by speech problems, facial weakness, or other features.
For more information on the recognition and emergency treatment of stroke, visit the American Heart Association website: http://www.strokeassociation.org/presenter.jhtml?identifier=1020.
I was reminded of this the other day, upon reading and responding to a question posed by a visitor to my website. This gentleman was on a hike in the northeast when he began to experience some tingling and weakness of one arm, accompanied by facial weakness and slurring of speech; fortunately, this resolved on its own over a few minutes. Nonetheless, he rightly worred about this, headed out, and spent some time in a hospital. In retrospect, he wondered if all of this could have been caused by too-tight backpack straps.
The quick answer to his question was "of course not". These sudden changes in his neurologic status could have represented a stroke; the fact that they resolved within minutes defined them as a "mini stroke" or transient ischemic attack (TIA). If it had been the start of an actual stroke, he would have had a very narrow time window of opportunity to receive a therapy which could prevent or minimize the develoment of long-term disability. In fact, this time window is so short I believe that a "walk out" evacuation (assuming the group is within an hour or so of a trail head and the individual is stable enough to walk) is preferable to staying put and sending for help.
The notion that this could have been caused by pack straps, however, is not unreasonable. I have written extensively about this in an article on this website. Go to the "publications" link and find the article curiously entitled "On numbness and tingling". Pressure of straps from a backpack on the nerves supplying the arms frequently causes numbness and tingling. This almost always occurs in both arms, however, and should never be accompanied by speech problems, facial weakness, or other features.
For more information on the recognition and emergency treatment of stroke, visit the American Heart Association website: http://www.strokeassociation.org/presenter.jhtml?identifier=1020.
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