Wilderness Medicine

Outdoor Medicine and the Environment Redux

2008-12-15T04:23:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

Earlier this year, I published a series of three posts based upon a commentary I wrote, entitled "Physicians and the Environment," that was published in the Journal of the American Medical Association. The commentary was an invited piece, and reflected some of my thoughts about current environmental issues and the role of the medical profession in achieving the education necessary to be able to intelligently respond to these issues. Recently, the AMA issued a statement supporting many of the concepts I presented in my commentary. Since that announcement, I’ve received numerous requests from readers of this blog to combine the posts into a single offering, which I offer here.

This post uses parts of my original commentary in JAMA to put this issue into context for the layperson, and so I am including the references where appropriate from the original commentary.

There is every reason for persons involved and interested in wilderness and outdoor medicine to be advocates for preservation of the environment. The entire concept of "wilderness medicine" is predicated upon the existence and improvement of wilderness areas, which are among the most pressured and rapidly receding parts of planet Earth.

In many circumstances in the past, the medical profession has responded to adverse situations of global reach, such as epidemic diseases, genocide, the threat of nuclear war and natural disasters. As the world’s scientists, governments, and businesses now confront the state of the environment, all manner of health care professionals also must be prepared to respond, because in the final analysis, health matters are integral to the predicament, predictions and discussion. Beyond being just a reliable resource, given the magnitude and complexity of issues as they relate to human health, the medical profession should accept the challenge of becoming a leader in the discussions and debates.

Despite our preoccupation with armed conflicts and the economy, the environment is perhaps today’s most pressing global issue, as it contributes not only to direct effects, but to other situations of concern, such as economic decline and civil disobedience. Environmental conditions contribute to the presence or intensity of many medical conditions, such as temperature-related morbidity and mortality, health effects of extreme weather events (e.g., storms, floods, tornadoes, hurricanes, and precipitation extremes) and their sequelae (e.g., oceanic algae blooms), ecological change (e.g., the potency of certain harmful plants, such as poison oak), starvation, allergies, pollution-related health effects, water- and food-borne diseases, and vector- and rodent-borne diseases.1,2

As we learn more, it becomes apparent that the full eventual effects of global climate change and other environmental issues are not necessarily easily defined or well predicted. There are multiple views surrounding every issue. Some of the most important issues that need to be continuously examined from every angle include global warming, depletion of stratospheric ozone and increases in ground-level ozone, destruction of forests, polar melting, deficiencies in water production and sanitation, and human population growth and dynamics.

There are and will be significant differences of opinions about what follows here. My comments are properly interpreted as being "pro-environment" or "green," leaning toward the perspective that advocates that there are significant environmental problems and that many of these can be attributed to the activities of humans. However, I most certainly acknowledge the rights and responsibilities of others to hold different viewpoints and opinions, and the value of their being skeptical about science and conclusions. The most important thing is that we do not become acrimonious or disengaged, because it will take all of our skills of observation, analysis, and collaboration to reach consensus on these matters in a timely fashion and in a way that promotes improvement, not conflict. The acts of remediation are expensive and potentially diverting (from other problems), so no significant change should be taken lightly.

Global Warming. Atmospheric accumulation of gases (predominately carbon dioxide, methane, nitrous oxide, and halocarbons) traps heat by the greenhouse effect.3 The Intergovernmental Panel on Climate Change predicted that average global temperature will continue to increase, and a major concern is the rate of warming.4 Compared with the century 1906-2005 required to raise the earth’s average atmospheric temperature by 0.56 degrees Centigrade, some suggest that only a decade may be needed to raise it another 0.28 degrees C.5 This rate of change has been created by burning fossil fuels in power plants and for transportation, a decline in carbon intensity reductions, and natural sinks removing a smaller proportion of emissions from the air.6 Each year, more than 1.2 cubic miles of oil, 3.5 billion metric tons of coal, and 100 trillion cubic feet of natural gas are burned worldwide, releasing 30 billion tons of carbon dioxide into the atmosphere.7 Without efforts to stabilize or decrease consumption of fossil fuels, the 14.9 billion metric tons of carbon emissions released by the United States, the European Union, China, and India in 2005 are projected to increase to 25.6 billion metric tons in 2030.8 Even if one disputes the precise numbers, we seem to be on an unsustainable spree of consumption. Is global warming due to rising carbon dioxide levels, and are these rising levels attributable to the activities of humans, or are these environmental "facts" part of a series of coincidences? We need to know the answer. How many barrels of oil, tons of coal, and cubic feet of natural gas can be extracted from the earth before we run out? At our current rates of consumption, when will this occur? We need to know the answers.

Depletion of Stratospheric Ozone. Chlorofluorocarbons and other ozone-depleting substances released into the atmosphere are major contributors to the destruction of ozone in the stratosphere. Depletion of the ozone layer exposes the earth’s inhabitants to increased amounts of harmful ultraviolet-B radiation. This contributes to skin cancer, cataract formation, suppression of the immune system, and damage to certain crops.9 This is counter-posed by accumulation of ozone at ground level, which contributes to lung disease and other health risks.

Destruction of Forests. Fires set to clear forests for agriculture and grazing release carbon dioxide, which is a contributing factor to global warming. According to the World Bank, approximately 22 million acres of rain forests are destroyed by intentional fires each year, accounting for approximately 20% of worldwide carbon dioxide emissions.10 Wildfires, often coinciding with droughts, generate additional atmospheric carbon dioxide.11 In preindustrial times, the atmospheric abundance of carbon dioxide was relatively constant at 280 ppm; in the 1950s, the level was 300 ppm; in 2006, it had attained 381 ppm; and in 2008 it is increasing.12 At what rate are these forests being re-planted? Can men and women continue to remove habitat, plants, animals, and minerals from planet Earth at current rates and be assured that this does not pose a catastrophic future for our populations of life forms? We need to know the answers.

Polar Melting. Consistent with the increase of global temperature, there is a loss of snow cover in the Northern Hemisphere, the amount of Arctic and Antarctic sea ice is diminishing, and glaciers are melting.13 Predictions suggest that in the next few centuries, sea levels could rise by as much as 17.8 cm to 6 m, and the Gulf Stream may be diminished or even eliminated.14 In low-lying coastal areas where populations cannot be protected by natural or artificial barriers, large numbers of climate refugees may be forced to migrate to other locations, thereby increasing population crowding. Global climate change also is predicted to contribute to flooding and fire risk; increase the intensity of cyclones (hurricanes) and heat waves; accelerate beach erosion and desertification; hasten species extinction; and diminish water and food (livestock, fish, and plants) availability.15 I have heard many arguments about animals, such as polar bears, that putatively face extinction because of hunting, habitat and climate change, loss of food supply, etc. Are important animal populations declining? Can or should we intervene in the decline of any species? What does history tell us about the effects of rising and falling sea level? We need to know the answers to these questions.

Deficiencies in Water Production and Sanitation. Sachs16 contends that global climate change will tighten the availability of water, and force migration of hundreds of millions of individuals over the course of a few decades. According to the United Nations, more than 5 billion persons on Earth may live under severe water stress by the year 2025.17 Currently, 1.1 billion persons lack adequate water worldwide, 2.6 billion lack adequate sanitation, and 1.8 million children die each year because of one or both of these deficiencies.18 The outdoors can be beautiful, marvelous, and a tonic for the body and spirit, but it can also be a cruel, terrifying environment of forced survival. What is the true status of our water supplies, nation by nation, region by region? We need to know.

Human Population Growth and Dynamics. The human population is increasing exponentially, which has an unprecedented global effect on ecology and biodiversity. This effect takes place through overharvesting, introduction of nonnative species, pollution, and habitat fragmentation and destruction.19 As large, developing countries face increasing energy demands, they will undoubtedly burn increasing amounts of fossil fuels. The environmental conditions and climate changes that have been touted as major influences on health may potentially involve millions of individuals being injured or killed by floods, tsunamis, and cyclones; tens of millions afflicted by poorly controlled diseases that might emerge as a consequence of unchecked vectors (such as mosquitoes); hundreds of millions malnourished due to desertification, loss of crops, and insufficient potable drinking water; and ultimately, poor health and the loss of prosperity as individuals are crowded into a reduced landmass that may be too small to reasonably support their survival.20,21 The worldwide growth of the human population dramatically increases the possibility of loss of life-sustaining resource bases during large geological and weather events in a manner that limits human survival. Simply put, the more pins standing behind the lead pin when the bowling ball strikes, the more that are vulnerable to being struck down and swept away. We need to be very thoughtful about this, because hunger and economic deprivation inevitably lead to conflict and even war. So, basic human needs may trump our desire to divert crops, such as corn, to alternative fuels. We are already witnessing these effects.

While there are a wide variety of opinions about the timeline for such events, the arguments supporting environmental trends are substantiated by reasonable scientific observations.2,22 Proponents of accelerating global climate change suggest that given the rapidity of changes and their unforeseen consequences, successful adaptation would appear unlikely and unattainable. The most viable solution is to halt the inexorable assault on the environment as quickly and effectively as possible. Arguments that do not support these trends are espoused by dispassionate and intelligent individuals, who also care very much about their planet, but do not necessarily agree with the scientific conclusions indicating human-generated planetary degradation and climate change. Which faction is correct? Issue by issue, point by point, we need to know. What might be at stake are the futures of species and resources that cannot be easily regenerated, if they can be regenerated at all. On the other hand, if there are better approaches than those currently favored by environmentalists, then let them be identified and implemented.

It is increasingly the case that environmental remediation recommendations are topics of great debate, for many reasons. Some reputable authorities do not agree with the proposed causation or acuity of environmental problems. Others astutely observe that some of the solutions proposed, such as diversion of crops for alternative fuels, may contribute to hunger and economic consequences that are more disruptive than expensive fuel, or even the consumption of fossil fuels.

Because the nature and magnitude of environmental changes have only recently come to be recognized, it is difficult to predict the attribution of inevitable to natural cycles, or whether the forces of nature are becoming unbalanced. Some suggest that while human activities have an effect on climate, there is not proof that this affects global temperature. For instance, there may be years during which global temperature declines. Others acknowledge the inevitability of global climate change, but recommend adaptation or geoengineering solutions.23 Opponents of those who predict irreversible global climate change and warming argue that until the precise nature and rate of these phenomena can be established, governments and industries should be tentative and cautious about making expensive policy decisions.24 Still, others point out that by focusing attention on global warming, there is a risk of not properly addressing more important environmental and health issues.

I am increasingly convinced that persons who argue against the magnitude and timing of global climate change are not doing so out of personal interests. They truly believe that our current surge in environmentalism is an over-reaction to a situation that may not be as dangerous as has been proposed. Wherein lies the burden of proof? Is it upon the conservationists, or those who demand data to support initiation of policies and practices with wide-reaching economic consequences? I think it is a shared responsibility. Beyond the data, we must certainly act with common sense.

Certain issues seem to me to be beyond calculated inaction. Developing alternative sources to substitute for fossil fuel consumption is widely supported. How can preservation of fossil fuels be bad, unless in the preservation, man unleashes some greater hardship upon the planet or its inhabitants? We are probably not yet at the stage where we should accept starvation in Africa as a consequence of our attempts to promote ethanol production for automobile fuel, but if we do not find a solution to pumping oil into our tanks, will be be creating even greater misery downstream? Despite the fact that there is almost universal assent and agreement on many issues, politics, economics, and special interests delay progress.

I cannot speak for everyone, but I have an opinion about the response needed from the medical profession. If one believes that there are situations upon which we should soon act, significant behavioral changes will be needed to begin to reverse apparent deleterious trends. Achieving global environmental change requires public and private efforts, led by a massive educational effort that should include all institutions of higher learning, including schools of medicine. By virtue of their knowledge and experience, physicians are rightfully concerned about individual and population health. However, the germs and disease processes with which we have become familiar may not pose as great a threat as what might result from such environmental eventualities as the melting of the polar caps.

It is my feeling that the time has come to broaden what the medical profession (and in particular, those with an interest in wilderness medicine) must learn, expanding awareness by educating physicians about the best environmental science. Given the hypothetical and known links of global climate change to human health, and the increasing concern that this change is accelerating, it is our duty to become informed.

Accordingly, in response to the environmental imperatives, an educational action plan is appropriate for the medical profession. Nelson25 noted about environmental studies, “ . . . the subject matter is all-encompassing. It includes . . . the air, water, minerals, soil, forests, oceans, lakes and rivers, as well as all living things in the seas and on land, the relationship and influence of each on the others, plus economics, politics, religion, culture, and philosophy. And, although we will never know or understand more than a small fraction of the endless intricacies of nature’s works, we can comprehend and learn the general principles that should guide our conduct as a society, if we are to preserve a livable habitat. The proposition is, quite simply, that we must conduct our activities in such a way as to protect the integrity of our ecosystems and their resources. . . ”

There are several potential methods for physicians and other healthcare professionals to increase awareness and involvement with environmental issues. First, there should be courses at every level on the relationship of environmental issues to human health. To cover the principles of environmental science and related medical issues, these courses should include information on atmosphere and climate; global climate change; the relationship of climate change and weather to disease vectors and transmission; the effect of climate change on the biology and afflictions of humans, plants, and animals; methods for assessing climate-related health effects; ecology and the environment; biodiversity and human health; natural environmental hazards; causes and effects of environmental contaminants; food and water science; and the causes and effects of population growth. Courses should be prepared and reviewed for accuracy and objectivity by authoritative environmental scientists and educators, in collaboration with medical professionals.

Medical societies and special interest groups, specialty organizations, and research institutes should whenever possible engage experts to summarize the best evidence about the effects of environmental change on health and medical conditions. This continuous process should foster exchange of views that takes into account medical, social, geopolitical, economic, and cultural issues. It goes without saying that the opinions that emanate from the medical profession, or any other profession for that matter, should be science-based to the greatest degree possible. Whenever new evidence emerges, current views may need to be modified as they relate to both the environment and health implications. I think it would be terrific if medical organizations would review their missions, and determine to what extent they are willing to disseminate environmental education material to their membership. Medical organizations should encourage members to become environmentally aware, and consider creating reports and multimedia presentations on global environmental health for delivery to medical professionals, students of medicine, business, government, and the general public.

Persons with special medical knowledge should investigate environmental organizations and consider supporting them with their special expertise. When appropriate, healthcare professionals can develop specific initiatives in collaboration with environmental professionals. Moreover, medical professionals should all learn about companies that truly use environmentally sound practices in their business efforts and consider supporting them. It may not make a big difference to the environment, but if for no other reason than to begin to establish a trend, hospitals and health care practices should make reasonable efforts to become green in ways that promote effective patient care while limiting the negative effect on the environment of providing that care.

And what about the wilderness medicine community? What can a person learn and do who wants to be healthy in the outdoors? The educational goals are to be better informed, become inspired, and take action. In the countless debates that will ensue, physicians and their patients should be positioned to wisely explain the medical ramifications of environmental issues. It is time to eliminate complacency and acknowledge the common “planetary patient” for whom we all share responsibility. Through education and personal resolve, each of us should strive to be active advocates for the environment.

image courtesy of National Museum of Australia Canberra

REFERENCES
1. Patz JA, McGeehin MA, Bernard SM, et al. The potential health impacts of climate variability and change for the United States: executive summary of the report of the health sector of the US national assessment. Environ Health Perspect. 2000;108(4):367-376.
2. Confalonieri U, Menne B, Akhtar KL, et al. Human health. In: Parry ML, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE, eds. Climate Change 2007: Impacts, Adaptation, and Vulnerability: Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, England: Cambridge University Press; 2007:391-431.
3. Collins W, Colman R, Haywood J, Manning MR, Mote P. The physical science behind climate change. Sci Am. 2007;297(2):64-73.
4. Parry ML, Canziani OF, Palutikof JP, van der Linden PJ, Hanson CE, eds. Climate Change 2007: Impacts, Adaptation and Vulnerability: Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel of Climate Change. Cambridge, England: Cambridge University Press; 2007.
5. Solomon SD, Qin M, Manning Z, et al. Climate Change 2007: The Physical Science Basis: Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, England: Cambridge University Press; 2007.
6. Canadell JG, Le Que´ re´ C, Raupach MR, et al. Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks. Proc Natl Acad Sci U S A. 2007;104(47):18866-18870.
7. Project Genie. Web site. http://www.projectgenie.org.uk. Accessed December 1, 2007.
8. International Energy Agency. Web site. http://www.iea.org. Accessed November 29, 2007.
9. Longstreth J, de Gruijl FR, Kripke ML, et al. Health risks. In: Environmental Effects of Ozone Depletion: 1998 Assessment. Nairobi, Kenya: United Nations Environment Programme; 1998.
10. World Bank Group. Pilot program to conserve the Brazilian rain forest. http: //www.worldbank.org/rfpp/overview/overview_what.htm. Accessed December 9, 2007.
11. Wiedinmyer C, Neff JC. Estimates of CO2 from fires in the United States: implications for carbon management. Carbon Balance Manage. 2007;2:10.
12. National Oceanic and Atmospheric Administration, Earth System Research Laboratory, Global Monitoring Division. Trends in atmospheric carbon dioxide. http: //www.esrl.noaa.gov/gmd/ccgg/trends/. Accessed January 15, 2008.
13. Nicklen P. Vanishing sea ice. Natl Geogr Mag. 2007;211(6):32-55.
14. BBC Weather Centre. Climate change. http://www.bbc.co.uk/climate/impact /gulf_stream.shtml. Accessed December 10, 2007.
15. Trenberth KE. Warmer oceans, stronger hurricanes. Sci Am. 2007;297(5):45-51.
16. Sachs JD. Climate change refugees. http://www.sciam.com/article.cfm? chanID=sa006&articleID=E82F5561-E7F2-99DF-36D3CB7EB5DA209C&ref=rss. Accessed January 12, 2008.
17. United Nations Water for Life. Fact sheet on water and sanitation. http://www .un.org/waterforlifedecade/factsheet.html. Accessed December 8, 2007.
18. World Water Council. Water crisis. http://www.worldwatercouncil.org/index.php?id=25. Accessed January 20, 2008.
19. Biodiversity & Human Health Web site. The effect of human population on biodiversity. http://www.ecology.org/biod/habitat/human_pop1.html. Accessed December 9, 2007.
20. Kerr RA. Global warming is changing the world. Science. 2007;316(5822):188-190.
21. Campbell-Lendrum D, Corvalan C, Neira M. Global climate change: implications for international public health policy. Bull World Health Organ. 2007;85(3):235-237.
22. Meehl GA, Washington WM, Collins WD, et al. How much more global warming and sea level rise? Science. 2005;307(5716):1769-1771.
23. Foreign Policy Web site. Why climate change can’t be stopped. http://www.foreignpolicy.com/story/cms.php?story_id=3980. Accessed December 9, 2007.
24. Botkin DB. Global warming delusions. Wall Street Journal. October 17, 2007;A19.
25. Nelson G. A clean environment and a prosperous economy: can we have both? J Wilderness Med. 1991;2(1):1-6.

Update on AMS and HACE

2008-12-01T05:32:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

This is the seventh post based upon educational sessions and syllabus material presented at the Wilderness Medical Society Annual Meeting & 25th Anniversary held in Snowmass, Colorado from July 25-30. This post relates expert advice about acute mountain sickness (AMS) and high altitude cerebral edema (HACE) from Dr. Peter H. Hackett, MD, FACEP, who is Director of Emergency Services at Telluride Medical Center and Director of The Institute for Altitude Medicine in Telluride, Colorado.

The incidence of acute mountain sickness (AMS) varies with location, depending on both absolute altitude reached and rate of ascent to altitude. It has been estimated that 15 to 40% of Colorado resort skiers (depending on the altitude of the resort) develop AMS, and studies have shown an incidence of 40% in Mt. McKinley climbers and 70% in Mt. Rainier climbers. Given the huge numbers of Colorado tourists (10 million a year), this is not a trivial problem. High altitude cerebral edema (HACE), or brain swelling, is defined as the progression of cerebral symptoms and findings of ataxia (difficulty with balance, walking, and muscular coordination) and change in consciousness.

The sleeping altitude is the critical factor, with 9,000 feet being a significant threshold for illness (>20% incidence), and 8,000 to 9,000 feet less of a problem (perhaps 10 to 15% incidence), while below 8,000 feet, AMS is uncommon (but still possible). Susceptibility to AMS is not related to physical fitness or gender, although women less frequently suffer from pulmonary edema (fluid in the lungs). Older adults may be less susceptible, while limited data suggest that children probably have the same incidence as does the general adult population.

Individual susceptibility and reproducibility are well documented. Contributing factors include low lung capacity, a less vigorous breathing response to conditions of low oxygen content in the blood, and exaggerated pulmonary hypertension (high pressures in the circulation of the lungs) in response to hypoxia (for high altitude pulmonary edema, or HAPE). Brain circulatory responses and dynamics play an important role, but are difficult to test at sea-level.

Currently, past history of AMS is the most significant risk factor and best predictor. Early diagnosis is the key to successful management and a high index of suspicion is critical. The setting is rapid ascent to a higher altitude in unacclimatized persons. The symptoms include headache, poor or no appetite, dizziness, nausea, insomnia, feeling tired, fatigue, and shortness of breath. Difficulty with (erratic) breathing is common during sleep, but not a sign of AMS. Early AMS feels exactly like a hangover. In the early stages, physical findings may be lacking. When advanced, the findings are those of fluid in the lungs and brain swelling. Ataxia, change in mental status and bluish skin discoloration (particularly noted in the fingers and toes and around the lips, also known as cyanosis) are the most useful indicators of serious illness.

The differential diagnosis of AMS includes dehydration, exhaustion, carbon monoxide poisoning (this is very important indoors, or in a tent or igloo), infections of lung or brain, viral syndromes, migraine events, transient ischemic attack (TIA, of the brain), hypothermia, drugs, and psychiatric problems.

The pathophysiology of moderate to severe AMS and HACE is clearly related to brain swelling. Whether early AMS, especially the headache, is due to brain swelling is not yet established. Factors contributing to brain swelling include, but are not limited to, the degree and rate of onset of hypoxemia (low oxygen content in the blood), inadequate breathing (known as hypoventilation, which can be due to low innate breathing response to hypoxemia, respiratory depressant drugs, or ascent too rapid for adequate acclimatization), poor gas exchange (oxygen for carbon dioxide) in the lungs, fluid retention, individual anatomy (such as ability to accommodate increased brain volume).

As brain volume increases, the pressure within the brain (intracranial pressure, or ICP) rises, although very little (perhaps only 20 to 30 milliliters) until a critical threshold is reached. A dehydrated brain is much more compliant than a “wet” brain. Dilation of cerebral blood vessels causes increased cerebral blood flow and increased cerebral blood volume, engorging the brain and making it stiffer and less compliant. As brain swelling continues, ICP rises beyond the ability of blood to flow into brain tissue. Eventually (and sometimes quite rapidly), cerebral blood flow stops, causing death.

Treatment is directed toward reducing brain volume and stopping any leak of fluid from the blood vessels into brain tissue:

1. Increase oxygenation and thereby reduce low oxygen concentration in the blood and tissues:

a. Descent - 1,000 feet may be adequate to effect improvement, but one should descend as far as is necessary until there is visible clinical improvement.
b. Administer supplemental oxygen if it is available. This is especially good for headaches and altered mental status.
c. Initiate hyperbaric oxygen therapy (e.g., within a portable pressure bag) if such is available

2. Speed the process of acclimatization:

a. Administer acetazolamide (Diamox) 125 to 250 mg by mouth every 12 hours. For children, the dose is 5 mg/kg of body weight/day. This drug promotes increased urination, stimulates ventilation, and decreases cerebrospinal fluid formation. Because acetazolamide carries some cross-reactivity with “sulfa” drugs, it should be used with extreme caution in persons suspected or known to be allergic to sulfa drugs.
b. Acclimatization at the same altitude is okay for mild AMS, but a sick person should never be left alone.

3. Treat symptoms:

a. For the headache, use analgesics.
b. For nausea and vomiting, use antiemetics, such as ondansetron (Zofran) dissolving wafer tablets 4 mg by mouth every 4 hours as needed

4. Reduce the fluid leak from the brain capillaries:

a. Administer dexamethasone 4 mg by mouth (or if a health care professional, by injection) every 6 hours. This may need to be continued until the victim is evacuated to a lower altitude, since rebound brain swelling may occur with cessation of this medication, and because the drug per se does not improve or hasten acclimatization.

Prevention of altitude illness:

1. As best possible, ascend slowly. “Climb high and sleep low.” The ideal rate of ascent is difficult to establish because of marked individual variation in the ability to acclimatize. A reasonable recommendation is to not sleep at an altitude 2,000 feet higher than the previous night’s sleeping altitude once above 8,000 feet. Take an extra day for acclimatization with every 3,000 to 4,000 feet of elevation gain.
2. A high (>70%) carbohydrate diet reduced AMS by 30% in some studies, but had little effect in other reports. It is not likely to be harmful and might help.
3. Avoid respiratory depressants (especially sleeping pills), and only ingest alcohol in small amounts.
4. Chemoprophylaxis:

a. Indications are forced rapid ascent or history of recurrent illness.
b. Take acetazolamide by mouth up to 5 mg/kg body weight/day divided into 2 or 3 doses, beginning one day prior and until one day after ascent. 125 mg twice a day may be sufficient for most persons. Recall that there may be a cross-reactivity (allergic reaction) in persons allergic or sensitive to “sulfa drugs.”
c. Take dexamethasone 4 mg by mouth every 6 to 12 hours, or 2 mg every 6 hrs. This is useful for persons intolerant of acetazolamide, or if the travel will be to extreme altitude. The drug may need to be continued for three or four days, since it does not speed acclimatization. It is commonly used by climbers on “summit day.”
d. Use of acetazolamide and dexamethasone simultaneously is promoted by some - acetazolamide to speed acclimatization and dexamethasone to prevent brain swelling, but only in first few days of ascent.
e. Ginkgo biloba was used in three studies, and shown to reduce AMS from 35 to 100%. It may be more effective during a moderate rate of ascent. The dose is 100 mg by mouth twice a day starting 2 to 3 days before and while at altitude. It is safe and inexpensive, but it has not been proven effective in all studies. Furthermore, preparations of the compound vary.

Sildenafil, altitude and exercise

2008-11-23T17:09:00Z

If you teach wilderness medicine you get used to questions about sildenafil (Viagra) and altitude illness.   While there are many drugs considered as prevention or treatment of altitude illness, sildenafil seems to tweak more interest – imagine that.    The questions do give me a sense of what people are talking about, and a recent inquiry on sildenafil and athletic performance sent me on a journey to look into that question.

The limited studies on sildenafil and altitude do not demonstrate it prevents acute mountain sickness (AMS).

It might be helpful in preventing High Altitude Pulmonary Edema (HAPE) in people who are susceptible to HAPE. The two operative words in that sentence are might and susceptible.   There is no evidence sildenafil will prevent HAPE in the absence of a sound acclimatization practice. Said differently, Viagra probably won’t protect you if you go too high too fast.

Sildenafil is used by some physicians as part of their drug regimen when treating HAPE, but it’s not first line medication and certainly not a miracle cure. In our layperson world it doesn’t replace early recognition, descent and oxygen as the mainstays of HAPE treatment.

The question of sildenafil and athletic performance is intriguing. An article in the New York Times speaks to research into it’s effect on athletic performance.   Sildenafil dilates arteries. This is how it works in erectile dysfunction, and how it is believed to help with HAPE (constricted and hypertensive pulmonary arteries are a trigger for HAPE). Dilated arteries may enhance delivery of oxygen to muscles and be a boon to athletes.

The ongoing research suggests this may be the case, maybe at sea level, perhaps more at altitude. However, there isn’t a lot of science yet, and the study I see most often referenced had only 10 participants. (J Applied Physiology June 2004). The study at Everest Base Camp had 14 participants (Annals of Internal Med 2004).

The athletic performance effect has prompted this medication to be considered as a performance enhancing medication with potential bans by those who ban such things.

Mountaineers, however, don’t need to give urine samples when they descend from a summit.   Will this concept drive a new wave of Viagra use? Maybe; mountaineers and other outdoor athletes are not immune from using performance enhancing substances.   It probably won’t make much impact on the drug company’s income. After all, the target for erectile dysfunction advertisements seems to be guys watching football, not altitude climbers.   It might make for interesting conversations around the campfire on the question of climbing “by fair means.”

Tod

November 08

Oral Ondansetron to Assist Oral Rehydration Therapy

2008-11-18T04:14:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

Oral rehydration can be a lifesaving therapy for persons, particularly children, suffering from dehydration. The most common cause of dehydration in children is infectious diarrhea.

When dehydration occurs, it is important to act swiftly. If fluid losses are significant, begin to replace liquids as soon as you can.

Oral Rehydration Salts (ORS) that meet World Health Organization standards are available in a dry mix; use one packet per quart (liter) of water. One packet contains sodium chloride 3.5 grams, potassium chloride 1.5 g, glucose 20 g, and trisodium citrate 2.9 g (or sodium bicarbonate 2.5 g). Cera Lyte 70 oral rehydration salts are based on a rice solution. One packet is mixed with a quart (liter) of water. After the solution is prepared, it should be consumed or discarded within 12 hours if kept at room temperature or 24 hours if kept refrigerated. Other ORS products available over-the-counter include Pedialyte, Enfalyte, Naturalyte, and Rehydralyte.

1. Mild diarrhea/hydration: Drink soda water, clear juices, broth, and electrolyte-containing sports beverages. If diarrhea is the cause, try to replace each diarrheal stool with 10 milliliters of ORS per kilogram (2.2 pounds) of body weight. If the child is vomiting, try to replace each episode of vomiting with 2 mL of ORS per kg (2.2 lb) of body weight.

2. Moderate diarrhea/dehydration: Drink diluted (by half, with water) electrolyte-containing sports beverages, mineral water (bottled), or a homemade solution (1 quart or liter of disinfected water plus 1/2 to 1 teaspoon, or 1.3 to 2.5 mL, of sodium chloride [table salt], 1/2 tsp of sodium bicarbonate [baking soda], 1/4 tsp, or 0.6 mL, of potassium chloride [salt substitute], and glucose [6 to 8 tsp, or 30 to 40 mL, of table sugar; or 1 to 2 tbsp, or 15 to 30 mL, of honey]). Take care not to over-sweeten (exceed 2 to 2.5% glucose) the solution with sugar, because this may worsen the diarrhea; too high a sugar concentration inhibits water absorption through the gastrointestinal tract. Each quart of this “home brew” should be alternated with 1/2 to 1 quart of plain disinfected water. Try to replace fluid losses at least every 2 hours.

When using ORS, try to get the victim to ingest a quart per hour until the frequency of urination begins to increase and the urine color turns light or clear. To begin, start with small (e.g. 5 mL or one teaspoon) amounts every 1 to 2 minutes, to avoid collection of a large amount of fluid in the stomach that might cause vomiting. A child should be given 11/2 oz (44 mL) of ORS per pound (0.45 kg) of body weight over the first 4 hours, then 1 ounce (30 mL) of ORS per pound of body weight per 8-hour period until the diarrhea resolves. Another estimate of fluid replacement for children is 100 ml (approximately 3 oz) of fluid per significant loose bowel movement. For an infant with diarrhea, decrease the amount of milk in the diet, and add more water, diluted juices, half-strength sports beverages, and ORS. Sweetened carbonated beverages (soda pop) are not good replacement fluids, because they contain too much sugar and little or no sodium and potassium. If the child is ***-fed, keep nursing (offer the *** more often). If the child is formula-fed, use ORS for 12 to 24 hours, then try switching back to formula. If the diarrhea persists switch back to ORS for another cycle. It is important to continue to provide nourishment with food (and calories) to children with diarrhea, not fluid alone. Avoid foods high in simple sugars (including tea, juices, and soft drinks). Try complex carbohydrates (rice, wheat, potatoes, bread, cereals) and yogurt, lean meat, fruits, and vegetables.

If premeasured salts are not available with which to supplement water, you can alternate glasses of the following two fluids, as recommended by the U.S. Public Health Service:

GLASS ONE — 8 oz fruit juice with 1/4 tsp (a “pinch”) table salt and 1/2 tsp honey or corn syrup (237 mL juice, 1.3 mL table salt, 2.5 mL honey or corn syrup)

GLASS TWO — 8 oz disinfected water with 1/4 tsp baking soda (sodium bicarbonate) (237 mL water, 1.3 mL baking soda)

Another homemade fluid mixture is 1 tsp (5 mL) table salt and 1 cup (275 mL) rice cereal in a quart (liter) of water; this must be used within 12 hours or discarded. If only fruit juice (without supplementation) is available, remember to cut it to half strength with water. Otherwise, the sugar content will be too high and may contribute to continued diarrhea. Estimation techniques to measure powdered ingredients (such as a “pinch” of table salt) are notoriously inaccurate, and can even be dangerous if you add excessive amounts. Use a proper measuring implement whenever possible.

3. Severe diarrhea/dehydration: Same as moderate. After a certain point, as with cholera, intravenous hydration may be lifesaving. See a physician as soon as possible.

Sometimes, offering liquids to drink is not sufficient to diminish the nausea and vomiting that accompany an episode of gastroenteritis. If a person cannot ingest sufficient liquid, the diarrhea persists. In a recent article in the Annals of Emergency Medicine (Ann Emerg Med 2008:52:22-29) entitled "The role of oral ondansetron in children with vomiting as a result of acute gastritis/gastroenteritis who have failed oral rehydration therapy: a randomized controlled trial," the authors concluded that in subjects with acute gastritis/gastroenteritis and mild to moderated dehydration who failed initial oral rehydration therapy, the proportion of children who subsequently required intravenous hydration was lower in a group treated with ondansetron (Zofran) in a dose of 0.15 mg/kg body weight of the oral dissolving tablet, as compared to a group that did not receive the drug.

Having suffered nausea and vomiting from acute infectious gastroenteritis while traveling, I can attest to the benefit of ondansetron in providing sufficient relief to allow me to be able to begin to drink liquids and thereby rehydrate. Given that this observation is fairly common among clinicians in the field, and that this study strongly points to a benefit of the drug for children in whom oral rehydration is prevented by persistent nausea and vomiting, it makes perfect sense to carry a drug such as this, with limited side effects, that might allow initiation of essential replenishment of body fluid.

To Thaw or not to Thaw

2008-10-15T19:56:00Z

I was recently asked what to do if you can't make it back to the trailhead in one day with frozen toes and have to spend the night in the field? How do you keep the toes from thawing while keeping the rest of your body warm?

This is a practical and real question. Thirty-four years ago I spent a night in a tent with my toes frozen, then walked 6 miles and traveled another 25 to a hospital. I know this situation first hand, or first foot as it were.

As so often happens in medicine, there is no easy answer. At every step of the way there are risks and benefits. What do we need to consider when making this decision?

If your feet are frozen, there are often accompanying issues of hypothermia, exhaustion, and dehydration that make walking unlikely. If you thaw a frozen foot in the field it’s hard to imagine walking. If you thaw a frozen toe or toes, you might be able to walk. Let’s talk about this scenario.

The benefit to frozen toes is the ability to walk. The risk is that the longer tissue is frozen, the worse the injury. Medicine can't give an exact timeline to help with this decision.

Practically speaking, keeping toes frozen is a challenge. It's likely your toes will slowly thaw overnight, especially if you can get inside shelter with clothing, sleeping bag, warm food and drink.

The benefit to rapid thawing in warm water, the treatment of choice, is that it gives the best chance for saving tissue. However, thawed toes often hurt and swell, and you put your toes at risk for a freeze-thaw-freeze injury, which is very likely to increase tissue loss.

Rapid thawing in warm water is easy to talk about in a classroom, but difficult to do in the backcountry. If you think your toes will thaw slowly, it’s better to “get er done” quickly. Hopefully, if warm water immersion isn't practical, your companion will donate their armpits or belly, which can work for thawing fingers and toes.

We weigh all these considerations-- some factors we’re sure of, others that are probable, but not certain-- and we make the decision.

In my case, it was desperately cold (minus 30F). I did sit up all night, and I kept my toes cold as I read Bradford's Washburn's classic frostbite pamphlet. It wasn’t fun, but it worked. My frozen toes, which still fit in my boots, began to thaw as I hiked out the next morning, but they were essentially still frozen at arrival in the hospital. I think I was lucky.

Tod

Oct 08

Poison Oak Allergic Contact Dermatitis

2008-10-14T03:58:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

Case Reviews in Clinical Dermatology, Volume 1 Issue 3, had an interesting discussion about certain aspects of poison oak/ivy dermatitis. The following are some of the points made by the authors, with additional comments by me:

"Contact dermatitis" (CD) is a broad term used to describe inflammation of the skin caused by direct contact with an irritating substance or allergen (a substance that induces an allergic reaction/response). Allergic contact dermatitis is a hypersensitivity reaction to a substance exposed to the skin to which a person has become allergic.

Sensitization to a substance can develop at any time, including adulthood. It may develop for substances that have been used repeatedly without any difficulty by an individual in the past. Poison oak/ivy allergic contact dermatitis is quite common. It is most likely to occur in persons with significant outdoor exposure, such as forest firefighters and backpackers. Sometimes a person may unknowingly encounter the allergen. For instance, urushiol in poison oak can persist on items such as clothes and gardening tools for years, and may be transmitted to a person from the fur of a pet, in the smoke of a campfire, or from a casual brush with plant that intrudes on a hiking path.

In general, a contact dermatitis eruption due to poison oak appears as itchy blisters, both large and small, on a reddened base in a linear (patterned in lines) distribution. Despite common belief, the fluid contained in the blisters does not spread the rash; only the urushiol resin itself can spread the rash. The resin in the is composed of a mixture of catechols and causes the hypersensitivity reaction when it comes in direct contact with the skin.

Urushiol is a water-soluble substance that can only be removed in significant amounts if washed immediately. Only 50% can be removed after ten minutes of contact, 25% after 15 minutes, and no resin can be removed after one hour of contact with the skin. Prevention of exposure to these plants is the most sensible, but not always the most practical solution. Many attempts have been made to prevent contact with the resin by applying topical skin protectants.

To make some treatment recommendations, the authors of the article offered a clinical case:

A 28-year-old, otherwise healthy man presented with a one-week history of a rash that began as small, itchy blisters on his inner arms a few days after camping in the Sierra Nevada Mountains. A few days later, he started to develop new large, red areas on his back. He felt somewhat fatigued but denied having fever or other symptoms. On physical examination, small blisters and black streaks were apparent in a cluster on his inner arm. There were other large reddened areas on his back. Based on his presentation, the diagnosis was "black spot poison oak contact dermatitis with systematization (spread to other parts of the body)."

The patient was treated with oral prednisone, starting at 60 mg per day and tapered by 10 mg per oral dose every 3 days. His symptoms resolved completely within two weeks.

According to the authors, this case illustrated an unusual presentation of poison oak contact dermatitis and the importance of rapid diagnosis and treatment. "Rhus dermatitis," commonly known as "poison ivy, poison oak, or poison sumac," and currently referred to as "toxicodendron dermatitis," is one of the most common forms of contact dermatitis (CD) in the U.S. It is characterized by itchy blisters on a reddened base in the setting of a history of exposure to an offending plant or some other vehicle (such as a dog's fur) that is carrying the resin.

Poison ivy grows in all states in North America with the exception of Alaska. Poison oak is separated into two categories: Western Poison Oak, which only grows on the Pacific coast of North America, and Atlantic Poison Oak, which is found mostly in sandy soils in the eastern part of the U.S. Poison ivy and poison oak are grouped with other toxicodendron dermatitis agents, including Japanese lacquer tree, cashew nut tree, poison sumac, and other members of the Anacardiaceae family of plants. Marked pruritus is typically the first symptom of toxicodendron dermatitis, beginning between the fingers, and on the eyelids, wrists, and top (opposite the palm) aspects of the fingers within 48 hours of exposure.

Itching is generally followed by inflammation and the characteristic appearance of a linear bumpy (raised) rash with blisters. As long as the plant oil remains on the skin, it can be transferred from the hands to other body parts. However, once the offending agent has been washed off, there is generally no further expansion of the rash, except in areas that have come in contact with the resin. In some cases, CD can become severe, covering over 20% of the body in adults and 10% of the body in children or manifesting systemically with fevers, fatigue (tiredness), and other symptoms.

The offending urushiol is an oleoresin that is both an allergen (causes an allergic response) and a primary irritant. It is a very resilient substance, and can persist for weeks to months on clothes, furniture, and animal fur. Typically, the allergic reaction to urushiol occurs within 24 to 72 hours, but it can be seen as quickly as six hours after exposure, particularly in highly sensitive individuals.

Black spot contact dermatitis is usually caused by poison ivy and poison oak, but can also be caused by sap from the Japanese lacquer tree, because the chemical structures of the oils in both plants are quite similar. When the resin from the Japanese lacquer tree comes into contact with skin, it turns black and attains a shiny appearance that becomes especially noticeable within the first 72 hours after exposure.

Black spot poison oak as a diagnosis can be challenging when the presentation consists of only asymptomatic black spots. Patients become concerned when these black spots, appearing as marker or ink spots, do not wipe off, and they sometimes confuse the lesions with melanoma. The ability of the resin to persist on clothes, fur, and tools for years can also complicate the picture since patients may deny a history of exposure because they are unaware of their contact with the resin. This pigment develops not only on the skin but on clothing as well. The black lesions cannot be washed off the skin and are followed by itchy blisters. They eventually peel off, and the skin heals without scarring.

This presentation is not commonly observed, probably because for the black lesions to occur, the skin needs to come into contact with a much higher concentration of plant sap. In most cases, persons experience only brief contact with the offending plant and then further dilute the concentration of oleoresin via perspiration or bathing so the appearance of black spots does not occur.

Regardless of whether or not black coloration occurs, after suspected exposure to the resin, the first step should be to wash the skin with soap to remove the urushiol and prevent further spread of the agent. This is most effective if done within 15 minutes of exposure. All clothes and any other items that came into contact with the offending plant should also be washed. Many patients find cool tub baths helpful in relieving the itching and edema associated with the rash, and oral antihistamines provide nighttime relief from itching. During the acute blistering stage, cool, wet dressings applied for approximately 20 minutes several times a day may help with swelling, especially around the eyes and on the face.

The decision to use topical or oral steroid medication(s) depends on a number of factors, including but not limited to age of the patient, severity of symptoms, amount of body surface area involved, and presence or history of a medical condition in which administration of an oral steroid could cause an adverse reaction.

The American Academy of Dermatology recommends topical steroid treatment only for mild cases. Typically, medium potency topical steroids are used, except on (delicate) skin around the eyes, which requires a less potent steroid. In general, the steroid preparations are liberally applied to the affected areas twice daily for 7 days. Oral steroids are used in more severe cases and in sufferers who have systemic involvement.

In severe cases, oral steroid courses (typically prednisone) are given at 0.75 to 1 mg/kg/day every morning, and this dose is tapered over a three-week period. Generally, oral steroids are tapered by approximately 10 mg every 2 to 3 days. For these severe, generalized cases, short (e.g., a few days) courses of low-dose oral corticosteroids have proven inadequate.

image of black spot reaction courtesy of Professional Education Services Group

Wilderness Risk Management Conference - 15 years later

2008-09-30T02:07:00Z

Fifteen years ago I opened the first WRMC in a large tent at the NOLS base in Conway Washington.   Today, amid the beautiful fall colors in Grand Teton National Park, I was looking at my notes from that presentation

Opening remarks WRMC 1994. Current Issues.
- Today the public demands more from wilderness educators, and we demand more of ourselves. This is still true. We wrestle to find the balance between risk management and adventure, worry whether we can make our programs too safe, and ask where we cross the line between risk management and program integrity. At some point, in order to sail, the ship needs to leave the harbor.
- We feel, either perceived or real, pressures from our litigious society and its seeming reluctance to accept responsibility for its actions. This is still true.
- We ask more of our staff in terms of their technical ability, experience and training. This is still true.
- We wrestle with the impact of technology in the traditional wilderness experience. In 1994 I didn’t imagine the communication, information, navigation technology available to us today. Nor did I anticipate how people have grown to expect these, to take them for granted as part of the wilderness experience. There are now field staff who have never worked in the pre-sat phone and GPS era.
- We try to explain our programs to people who seem more and more disconnected from wilderness. This was before we worried about children who did not even go outside.

Where have we gone in 15 years?
Industry-wide dialogue on risk management was, and is a goal in the formation of this committee and this conference.   We’re more knowledgeable. Our risk management practices are better.   We have better lines of communication. We have more resources; in people, information and experience.

Yet the issues are in many ways the same. I could say the same things today that I said in 1994. They remain relevant.

What I didn’t say then, but wish I had, is that we can develop risk management systems and programs, have sound training and support materials and good lines of communication, but ultimately, our ability to be present when a staff person and a participant are engaged in a real time decision is limited. Lets keep this focus on the person in the field making the decisions, the person at the sharp end of the rope, with their hands on the tiller and their eyes on the terrain and weather.   For this ultimately is the core of risk management in our programs and our most valuable tool.   It still comes down to the competence and judgment of our people in the field - and this is a good thing.

Rabies Vaccine Shortage

2008-09-25T03:08:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

The American College of Emergency Physicians has just alerted emergency physicians that because of a shortage of rabies vaccine, they need to obtain a confirmation code from their state health department before ordering doses of the vaccine for post-exposure prophylaxis.

Here is some information about rabies:

Rabies virus infection occurs more frequently in wild than in domestic animals. In some foreign countries where immunization of animals is infrequently practiced, the risk is great even in domesticated animals. The virus is carried in saliva and is transmitted by bite or lick (if the skin is broken). It has been transmitted by bats in caves either by aerosolized saliva or undetected bites. Raccoons, dogs, cats, foxes, coyotes, skunks, wolves, bats, woodchucks, and groundhogs are the most common carriers. Rabies has not been reported in bears. Although rabbits, hares, mice, squirrels, chipmunks, rats, guinea pigs, and ferrets may be rabid, they are rarely involved in the transmission of rabies to humans. Domestic animals such as cattle, horses, and sheep become infected in regions where skunk or raccoon rabies is found. In developing countries in Asia, Africa, and South and Central America, dogs are the most common carriers.

Animals with rabies show abnormal behavior. In the “furious” phase, they are hyperactive, may have a fever, are overtly aggressive, and salivate excessively. With “dumb” rabies, they appear tired, lack coordination, and may become paralyzed.

Because of rabies risk, all wild animal bites or scratches, and bites or scratches of unregistered or strangely behaving cats and dogs, should be reported to the appropriate public health authority. If the animal is a pet with otherwise normal behavior, it should be observed for 10 days. If the animal is rabid, it will become very ill or die during that time, and its brain tissue can be analyzed for the presence of rabies. If the animal is a pet with unusual behavior, or a captured high-risk wild animal, it should be killed and examined. If it is a high-risk animal and cannot be captured, it must be presumed to be rabid.

Immediately scrub an animal bite wound or a wound that has been licked by a potentially rabid animal vigorously with soap and water. If benzalkonium chloride 1% (Zephiran); 10% povidone iodine (Betadine) solution (less effective); or, in a pinch, Bactine (benzalkonium 0.13%) antiseptic is available, one of these should be used to irrigate and deeply swab the wound, since they may kill rabies virus.

The standard instructions in times of plentiful rabies vaccine supply are:

If rabies is a consideration, the victim should seek the assistance of a physician, who will determine the need for postexposure rabies vaccination (a series of five injections) and injection of antirabies serum (human rabies immune globulin; as much as possible is injected around the bite wound, and the remainder intramuscularly). A person who has been previously immunized against rabies still needs two booster doses of rabies vaccine after high-risk contact with a rabid animal. In countries (Africa, Asia) where rabies in very prevalent in dogs and cats, the vaccination status of the biting animal should be ignored, because the vaccination may not have occurred or may have been ineffective. Begin vaccination and then discontinue after 10 days if the animal is observed to remain healthy during that time period.

Preexposure vaccination against rabies should be administered to people at high risk of exposure (animal handlers, cavers, hunters, and trappers in rabies-endemic areas, along with travelers to certain foreign countries). This is given as a series of three intramuscular injections over 28 days, although a newer 1 week schedule for the injections appears to be quite effective. An intradermal regimen can be used for immunization, but this technique may result in lower antibody level.

The incubation period of rabies ranges from 9 days to more than 1 year, but is usually between 2 and 16 weeks. The first symptoms are fatigue, weakness, anxiety, irritability, fever, headache, nausea and vomiting, sore throat, abdominal pain, and loss of appetite. Some victims complain of numbness and tingling where they were initially bitten. After a few days to 2 weeks, the virus shows its devastating effect upon the nervous system, with symptoms of increased agitation, hyperactivity, seizures, hallucinations, uncontrollable behavior, and inability to drink (hydrophobia) due to muscle spasms in the throat. This constellation is called “furious rabies.” With “dumb” rabies, a person becomes progressively weak, uncoordinated, and paralyzed. Unfortunately, rabies is virtually always fatal, with the terminal events being one or more of coma, respiratory failure, seizures, abnormal heart rhythms, paralysis, and pneumonia.

To avoid rabies, be certain that all pets and livestock are properly vaccinated, do not feed or handle wild animals, do not feed or touch stray animals, avoid sick or strange-acting animals, keep garbage and food (including feed for animals) covered and away from wild animals, do not keep wild animals as pets, do not touch or pick up dead animals, and do not handle bats.

With the current vaccine shortage, the protocol for post-exposure vaccination has been modified. Complete details are found at the CDC website dedicated to information about rabies. To emphasize some of the information:

As of August 29, 2008, Sanofi Pasteur in coordination with the Centers for Disease Control and Prevention (CDC) will resume shipping IMOVAX® Rabies, Rabies Vaccine for post-exposure prophylaxis only. Novartis Vaccines will no longer be shipping supplies of RabAvert®.

For a physician to obtain IMOVAX rabies vaccine, he or she must first contact the appropriate Rabies State Health Official so that a risk-assessment can be conducted for the suspected exposure. If the Official determines that post-exposure prophylaxis is required, the inquiring physician will be provided with a pass code to place on the Sanofi Pasteur Rabies Post-Exposure Form. The form must be filled out in its entirety, including the required physician’s signature and pass code provided by the Rabies State Health Official. Sanofi Pasteur may be contacted at 1-800-VACCINE to obtain the required form.

Vaccine availability for pre-exposure vaccination continues to be limited, and will be distributed on approval from state and federal public health authorities for those first responders with a critical need and in consideration of available supplies. These measures will allow responsible management of currently limited supplies of this vaccine for individuals at highest risk of exposure.

Why is there an interruption in supply?

Starting in June 2007, Sanofi Pasteur began renovating its IMOVAX Rabies vaccine production facility in France to maintain compliance with the most current requirements from FDA and the French regulatory body. Prior to these renovations, Sanofi Pasteur established an inventory based on historical levels of sales and projected market demand. The facility is scheduled to be approved and operational by mid-to-late 2009. Until the facility is operational, Sanofi Pasteur has a finite amount of IMOVAX Rabies vaccine.

After the renovations began, Novartis, the other supplier of rabies vaccine for the United States, was unable to meet projected rabies vaccine supplies. Since early 2008, Novartis has been supplying its rabies vaccine, RabAvert, for post-exposure use only. Consequently, Sanofi Pasteur has been supplying nearly all of the market for rabies vaccine. The increase in demand for IMOVAX is outpacing the company’s historical levels of supply.

Persons at increased risk for rabies exposure should take appropriate precautions to avoid rabies exposure. Vaccine is available for pre-exposure prophylaxis, and providers should consult with their local or state public health department to ensure appropriate use of such prophylaxis. General rabies awareness and prevention messages should be emphasized to avoid exposure (e.g., avoid wildlife contact, vaccinate pets/livestock, capture/observe/test exposing animal, etc.).

Lightning Precautions

2008-09-09T03:41:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

Spring, summer (peak season), and autumn are the seasons during which we witness most thunderstorms, and during which people and animals are struck by lightning. The National Oceanic and Atmospheric Administration indicates that approximately 50 Americans are struck and killed each year by lightning.

One of the world's experts on lightning injuries is Dr. Mary Ann Cooper, who is Professor of Emergency Medicine and Director of the Lightning Injury Research Program at the University of Illinois at Chicago. This year, Dr. Cooper was the recipient of the Research Award from the Wilderness Medical Society at its annual scientific meeting held in Snowmass, Colorado. She is also senior author of the chapter on lightning injuries in the textbook Wilderness Medicine.

As Dr. Cooper has noted, most people seriously underestimate the risk of being struck and do not know when or where to take shelter. NOAA data indicate that of persons struck and killed by lightning, 25 percent were standing under a tree and 25 percent occurred on or near the water. It is logical that nearly all persons killed by lightning are struck outdoors, so it is very important that everyone who might be caught in a thunderstorm be able to make a rapid assessment of the risk, and seek the best shelter or protective positioning possible. This is a personal responsibility for most, and a very important skill for group leaders.

Here is some information intended to help you understand the behavior of lightning in order to improve avoidance techniques:

1. Lightning strikes the earth at least 100 times per second during an estimated 3,000 thunderstorms per day. Fortunately, the odds of being struck by lightning are not very great. The wise traveler respects thunderstorms and seeks shelter at all times during a lightning storm.

2. Thunder, which is always present with lightning, is attributed to the nearly explosive expansion of air heated and ionized by the stroke of lightning. To estimate the approximate distance in miles from your location to the lightning strike, time the difference in seconds between the flash of light and the onset of the thunder, and divide by five.

3. Lightning can injure a person in five ways:

A. Direct hit, which most often occurs in the open.
B. Splash, which occurs when lightning hits another object (tree, building). The current seeks the path of least resistance, and may jump to a human. Splashes may occur from person to person, or from a metal fence.
C. Contact, when a person is holding on to a conductive material that is hit or splashed by lightning.
D. Step (stride) voltage (or ground current), when lightning hits the ground or an object nearby. The current spreads like waves in a pond.
E. Blunt injury, which occurs from the victim’s own muscle contractions and/or from the explosive force of the shock wave produced by the lightning strike. These can combine to cause the victim to be thrown, sometimes a considerable distance.

4. When lightning strikes a person directly, splashes at him from a tree or building, or is conducted along the ground, it usually largely flows around the outside of the body (flashover phenomenon), which causes a unique constellation of signs and symptoms. The victim is frequently thrown, clothes may be burned or torn (“exploded” off by the instantaneous conversion of sweat to steam), metallic objects (such as belt buckles) may be heated, and shoes removed. The victim often undergoes severe muscle contractions—sufficient to dislocate limbs. In most cases, the person struck is confused and rendered temporarily blind and/or deaf. In some cases, there are linear (11/2 to 2 in, or 1.3 to 5 cm, wide, following areas of heavy sweat concentration), “feathered” (fernlike; keraunographism; Lichtenberg’s flowers—cutaneous imprints from electron showers that track over the skin), or “sunburst” patterns of punctate burns over the skin, loss of consciousness, ruptured eardrums, and inability to breathe. Occasionally, the victim ceases breathing and suffers a cardiac arrest. Seizures or direct brain damage may occur. Eye injuries occur in half of victims.

5. A victim struck by lightning may not remember the flash or thunder, or even recognize that he has been hit. The confusion, muscle aches, body tingling, and amnesia can last for days. With a more severe case, the skin may be mottled, the legs and/or arms may be paralyzed, and it may be difficult to locate a pulse in the radial (wrist) artery, because the muscles in the wall of the artery are in spasm. First-, second-, or third-degree skin burns may be present. Broken bones are not uncommon.
If a person is found confused, burned, or collapsed in the vicinity of a thunderstorm, consider the possibility that he was struck by lightning. The victim is not “electrified” or “charged”—you will not be jolted or stunned if you touch him.

6. If you are in the vicinity of a thunderstorm, seek shelter for the victim and yourself. Lightning can strike twice in the same place!

Lightning Avoidance

1. Know the weather patterns for your area. Don’t travel in times of high thunderstorm risk. Avoid being outdoors during a thunderstorm. Carry a radio to monitor weather reports. Lightning can lash out from 10 miles in front of a storm cloud, in seemingly clear weather. If you calculate (see above) that a nearby lightning strike is within 3 miles (5 km) of your location, anticipate that the next strike will be in your immediate area. The “30-30 rule” specifies that if you see lightning and count less than 30 seconds prior to hearing thunder, seek shelter immediately. Since thunder is rarely heard from more than 10 miles away, if you hear thunder, it is best to curtail activities and seek shelter from lightning. Do not resume activities outdoors for at least 30 minutes after the lightning is seen and the last thunder heard.

2. If a storm enters your area, immediately seek shelter. Enter a hard-roofed auto or large building, if possible. Tents and convertible autos offer essentially no protection from lightning. Tent poles are lightning rods. Metal sheds are dangerous because of the risk of side splashes. Indoors, stay away from windows, open doors, fireplaces, and large metal fixtures. Inside a building, avoid plumbing fixtures, telephones, and other appliances attached by metal to the outside of the building.

3. Do not carry a lightning rod, such as a fishing pole or golf club. Avoid tall objects, such as ski lifts and power lines. Avoid being near boat masts or flagpoles. Do not seek refuge near power lines or tall metal structures. If you are in a boat, try to get out of the water. If you are swimming in the water, get out. Do not stand near a metal boat. Insulate yourself from ground current by crouching on a sleeping pad, backpack, or coiled rope.

4. Move off ridges and summits. Thunderstorms tend to occur in the afternoon, so attempt to summit early and be heading back down by noon. In the woods, avoid the tallest trees (stay at a distance from the tree that’s at least equal to the tree’s height) or hilltops. Shelter yourself in a stand of smaller trees. Avoid clearings—you become the tallest tree. Don’t stay at or near the top of a peak or ridge. Avoid cave entrances. In the open, crouch down or roll into a ball.

5. Stay in your car. If it is a convertible, huddle on the ground at least 50 yards (46 m) from the vehicle.

6. If you are part of a group of people, spread the group out so that everyone isn’t struck by a single discharge.

7. If your hair stands on end, you hear high-pitched or crackling noises, or see a blue halo (St. Elmo’s fire) around objects, there is electrical activity near you that precedes a lightning strike. If you can’t get away from the area immediately, crouch down on the balls of your feet and keep your head down. Don’t touch the ground with your hands.

8. The StrikeAlert Personal Lightning Detector (Outdoor Technologies, Inc.) is the size and configuration of a pager and uses an audible warning and LED display to show the wearer how far away lightning is striking and if a storm is approaching or leaving.

Handwashing, Giardia and old Tales

2008-08-27T16:18:00Z

Once there was a time, days of freedom and ignorance vaguely remembered as the 70’s, when we didn’t worry about wilderness water quality. We drank when and where we pleased. Yes, there was a tale of backpackers in Utah who became ill with “beaver fever” caused by Giardia, but we tried to ignore this challenge to our assumptions. The die was cast, however, and discussions began over whether we needed to disinfect the water.

Physician and outdoor educator Thomas Welch wrote an editorial on water disinfection in the Journal of Wilderness and Environmental Medicine 2004. He points out that this classic 1976 Utah incident of Giardia caused diarrhea, which brought this protozoa to our attention and probably sparked the water disinfection era, looks in hindsight like a hygiene, not a water disinfection problem. Other groups using the same area didn’t get sick, cysts could not be isolated from the water, and the patients all became ill at the same time, and with a short incubation period, suggesting this was not a waterborne protozoa illness.

Giardia’s reputation is enhanced by an association bias. People go camping, get diarrhea and assume the source was the water. This perception is encouraged when the diagnosis of Giardia is based on a history of a recent camping trip, but without testing. The patient leaves believing they may have Giardia, when in fact there is often no proof. They leave thinking it was the water they drank, when the cause of the illness may have been hand-to-mouth transmission. They might need a lecture about hand washing from their health care provider, along with the advice to be more diligent with water disinfection.

The editorial makes the point that water disinfection is not a substitute for hand washing or alcohol-based hand cleaners.

Someday we may have the science to give us a better sense of when we need to disinfect water. Until then, routine water disinfection has low health risks and is prudent. And hygiene, especially hand washing, is vital for avoiding illness on a wilderness trip.

Welch, TR. Evidence-based medicine in the wilderness: The Safety of Backcountry Water. 2004. Wilderness Environ Med. 15:235-237.

Summer Health Tips

2008-08-03T18:03:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

I was recently invited by Revolution Health to offer their readers a few summer safety tips to beat the "silent summer spoilers." The following is a modified version of what was presented, with the notation that these afflictions are not so silent, and can certainly ruin your vacation or outdoor adventure.

Sunburn can be brutal. The best way to avoid sunburn is to stay out of direct sunlight. If possible, stay in the shade, and wear sun-protective clothing. Use a sunblock that is effective against both ultraviolet A (UVA) and UVB rays. It is an increasingly prevailing opinion that UVA is more damaging than previously thought.

Be certain to obtain a good application (at least an ounce or two for a "normal" sized adult), and reapply the sunscreen often, particularly if you are sweating or spending time in the water (scuba diving, surfing, swimming, etc.). If you are taking medication, know if it might make your skin more sensitive to sunlight.

Pay attention to your surroundings. High altitude, wind, and sun reflecting off the surface of water, sand, or gravel add to UV exposure. Don't forget to protect your eyes with sunglasses rated to block nearly 100% of UV radiation. If you decide to use insect repellent containing DEET (N,N-diethyl-m-toluamide) as well as a sunscreen, be advised that the combination might reduce the effectiveness of the sunscreen. If you are using two separate products (sunscreen and insect repellen), in general, it is best to apply the sunscreen first, allow it to absorb into the skin for 20 to 30 minutes, then apply the insect repellent, in order to maximize the effect of the repellent. If you are going to be in water where you might come in contact with stinging jellyfish, consider using Safe Sea sunblock with jellyfish sting protective lotion incorporated into the product.

A mild sunburn without blistering can be treated with cool compresses, showers or baths, a non-sensitizing skin moisturizer lotion, and aspirin or a nonsteroidal anti-inflammatory drug (e.g., ibuprofen) to decrease inflammation. A sunburn, even first degree, that is so extensive that it causes the victim to suffer chills, nausea and vomiting, weakness, and diarrhea, may require oral rehydration and bedrest. If blisters are present, this indicates second-degree burns, which sometimes must be treated with topical antiseptic ointment, bandages, and more extensive medical care. You certainly wish to avoid this situation. The skin bubbling and peeling that follow a first degree sunburn are superficial and do not result in fluid loss, and rarely lead to infection, but the skin should be kept clean and moisturized to prevent any complications. Anyone with a severe sunburn of any sort should be examined for dehydration.

Blisters are the bane of hikers and trekkers, and often of persons wearing new sandals, particularly if the feet are dirty and dusty, as the grit and grime serve as agents of abrasion. Break in andy new shoes, boots, flip-flops and sandals before walking any distance in them. Keep your feet clean and dry. When walking in boots, wear a thin pair of liner socks under your regular socks, so that the friction is between the socks, not between the boots and your feet. Cushion any reddened "hot spot" or cover it with a BlistOBan® bandage before a fluid-filled blister appears. If you do get a blister:

Fasten a "donut"-shaped foam pad to the perimeter of the affected area. Cover the affected area ("donut hole") with a fitted hydrogel (e.g., Spenco 2nd Skin®) pad, and then place tape over the foam and hydrogel. Watch for signs of infection, which include cloudy fluid or pus within the blister, or red streaks emanating from the edges of the blister into the surrounding skin. If the blister appears infected, use a disinfected or carefully cleaned needle to create a small puncture at the edge of the blister, and drain it. Cover the open wound with antiseptic ointment, and apply a sterile dressing.

Sprains and strains are common ailments in the summertime due to increased outdoor activity. The most common sprain involves the ankle. In the event of a sprain, use the "RICE" technique. RICE stands for "rest, ice, compression, elevation." Try to rest the joint. Elevate the affected body part and apply ice packs intermittently (e.g., 15 minutes on, 15 minutes off) as much as is practical for the next 24 hours. If the skin becomes reddened and painful from the application of ice, ease off to avoid a cold injury (e.g., frostbite) to the tissues. Mild compression with a wrap may provide some pain relief. If you need to keep walking, tape, bandage or splint the joint for support.

Once a joint is weakened by a strain or sprain, re-injury is common. Take precautions by using a mechanical ankle support (e.g., brace and high-top shoes or boots) and/or a walking stick over rocky terrain. It takes a full 6 to 8 weeks to recover from a mild ankle sprain, and 3 to 6 months to recover from a severe sprain.

Gastroenteric problems are common in the summer. Traveler's diarrhea, commonly caused by the bacteria E. coli, is often due to water or food contamination. Failure to wash or "gel" hands or to properly prepare food are likely the most common errors that lead to diarrhea. Water disinfection techniques include heating, addition of chemicals, filtration, or application of UV light. It is important to carry redundant water disinfection systems, so that if a unit (e.g., filter) is lost or damaged, you have backup. Avoid drinking beverages with ice, unless you can be absolutely certain that the ice was prepared from properly disinfected water.

Tick and mosquito bites can result in serious, even fatal, infections. So, be certain to protect yourself. If circumstances permit, wear light-colored pants tucked into socks and paired with a long sleeve shirt. Wear a head net or use a bed net when needed. Use insect repellent(s). Permethrin is applied to clothing, while DEET or picaridin is applied to exposed skin. Perform regular "tick checks" of the entire body (especially the scalp, groin and armpits), and immediately remove ticks. When attempting to remove a tick, do not twist it, touch it with a hot object such as a hot match head, or attempt to suffocate or kill it with petrolatum (petroleum jelly), mineral oil, kerosene, stove fuel, etc. These techniques might cause the tick to struggle and regurgitate potentially infectious agents into your bloodstream.

Finally, learn to recognize poison ivy, oak, and sumac. If you become exposed to their resin, immediately wash it off with soap and water or with a specialized scrub (e.g., Tecnu or Zanfel) within 30 minutes if possible. To treat a rash from poison ivy, oak or sumac, you may soothe the affected skin with calamine lotion and also consider the following measures: apply a topical anesthetic, such as praxomine HCl 1%; soak in a tepid (not hot) bath supplemented with baking soda or Aveeno (contains oatmeal proteins); consider taking an antihistamine medication, which helps control itching and acts as a sedative. Consult a physician if the reaction is severe. Prescription treatment (such as corticosteroid therapy) may be required.

The resins from plants can remain on clothes, fabrics, backpacks, tents, pet fur and elsewhere for long periods of time, so be certain to wash these carefully to prevent further exposure to the resin. Once the rash appears, you are not contagious, and you cannot spread the rash by scratching. However, you can open up blisters and make the affected skin vulnerable to secondary infection.

image courtesy of w3.ouhsc.edu

Epinephrine Roundtable

2008-07-28T20:19:00Z

Last evening I sat on a roundtable discussion on the the use of epinephrine in the backcountry at the 25th Anniversary and Annual Meeting of the Wilderness Medical Society.

Dave Johnson MD from Wilderness Medical Associates was the initiative on this project. The panel, moderated by Jay Lemery MD, included Dr Johnson, myself, Flavio Gaudio MD from Cornell, attorney Frances Mock, Carl Weil and Joanne Vitanza MD from Versus Pharmaceuticals (the Twinject people).

Highlights from the discussion include:

It’s difficult to know how common anaphylaxis is, both in the city, and the backcountry. Definitions vary and hinder reporting. The incidence of this rare, but deadly reaction is probably influenced by where and when program operates; some places have more bee and wasp stings, for example.

Data collection has been a disappointment. There have been several efforts over the years, but no compelling reason, other than AEE accreditation, for outdoor programs to submit data to a common database. This epinephrine argument is a clear example of where diligence in data collection would be of value.

In the absence of solid numbers our perceptions are influenced by the emotional hook of anaphylaxis.   Tales of patients with severe allergic responses saved with epinephrine circulate in the industry, yet documented accounts are elusive.     NOLS, for example, has only 2 incidents in the past 24 years where epinephrine was used for anaphylaxis (and no incidents where epinephrine was indicated and not administered). The 1998-2005 WRMC data set, which includes 960,000 program days of back-country experience, has no incidents of anaphylaxis. Dave Johnson, based on his experience, thinks these numbers are a low cohort.   I can’t disagree, the evidence does not allow us to draw conclusions about frequency.

We want to be prepared to treat this problem, yet worry that a layperson administering epinephrine to another person may not be supported by law.   Frances spoke to the legal dilemma of the law being behind the current medical standard of care.   Dave Johnson notes that the “horse is out of the barn” and the law will change to support layperson use of epinephrine, it may just take some time.

There may be an expectation by parents and clients, driven by the attention to food allergies in the media, that the person in charge should be able to manage anaphylaxis, yet the legal support for epinephrine use by laypeople as a first aid skill, while improving, remains inconsistent state by state.

A few states give Good Samaritan support to people administering epinephrine in an emergency. Some states mandate training for camp counselors. Some states have clear training requirements, others leave training to the equivalent of local medical control (e.g., physician, nurse practitioner). Some states include school bus drivers on the list for training, others do not allow EMT’s to initiate epinephrine treatment in the field (which of course, seems silly).

There are a number of advocacy groups supporting administration of epinephrine in anaphylaxis by well-trained first responders (school teachers, coaches, nurses, bus drivers, etc.). These include the Food Allergy & Anaphylaxis Network and medical organizations such as the American Academy of Allergy, Asthma and Immunology, American Academy of Pediatrics, the American Medical Association), the Red Cross and the American Heart Association in the 2005 First Aid Guidelines. We hope our roundtable discussion leads to a similar statement of support by the Wilderness Medical Society for layperson use of epinephrine in the wilderness.

National Estimates of Outdoor Recreational Injuries

2008-07-26T16:44:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

In Volume 19, Number 2 (2008) of the journal Wilderness & Environmental Medicine appears an original research article entitled "National Estimates of Outdoor Recreational Injuries Treated in Emergency Departments, United States, 2004-2005," authored by Adrian H. Flores and his associates from the Division of Unintentional Injury Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia. This article was the beneficiary of multiple press releases, and so there has already been a fair amount of discussion regarding its findings. Because I was briefly quoted regarding this article by the Associated Press, I have received a fair number of inquiries about its significance.

This article is the first to provide national estimates of nonfatal outdoor recreational injuries treated in 63 U.S. emergency departments (EDs). The data were gathered using the National Electronic Injury Surveillance Survey System - All Injury Program. In this way, national estimates of outdoor recreational injuries were calculated, and activities leading to injury, demographic characteristics, principal diagnoses, and primary body parts affected were described.

Averaged across the study years, an estimated 212,708 persons were treated each year in U.S. EDs for outdoor recreational injuries. Males accounted for 68.2% of the injuries, but the rates of injury did not take into consideration that males have higher rates of participation in outdoor recreation. The lower limb, upper limb, and head and neck region were the most commonly injured body regions. Fractures and sprains or strains were the most common diagnoses. For all injuries, the leading causes were falls, being struck by or against an object, and overexertion. In this study, the 10- to 19-year old and 20- to 29-year old ages groups accounted for the greatest percentage of injuries. Snowboarding, sledding, and hiking were the leading activities associated with outdoor recreational injuries.

What can be learned from this study? Much of what was documented is fairly well appreciated already, and confirms our suspicions about who suffers what type of injuries. As with any type of epidemiological research, the devil is in the details. For instance, to understand about how to make use of the information about injuries in snowboarders, it would be necessary to understand what happened during each event - did the accident occur at the beginning of the day (? icy terrain or deep powder) or at the end of the day (? participant tired, evolving icy conditions, impending darkness); was the snowboarder wearing protective equipment (? wrist guards, leash, helmet); was the snowboarder experienced (? beginner, intermediate, expert), etc. To understand how to make use of the information about injuries in hikers, it would be important to know the nature of the terrain, the skill-strength-experience of the hiker, the environmental conditions, type of footgear, use of a walking stick, etc. The premise is that with some reasonable degree of detail, we can draw conclusions about how better to prevent accidents and injuries. The name of the game is injury prevention.

One cannot remove all risks from outdoor recreational activities, but a reasonable goal would be to remove all unnecessary risks. If a deeper analysis of this study reveals that injured boaters were all driving above a certain speed, we can perhaps conclude something from that and perhaps make recommendations. If a greater percentage of the head-injured among the study persons were without helmets than the participating population at large, then we can perhaps make a recommendation. This is a nice study that will hopefully inspire others to look with greater depth at specific areas of outdoor recreation in order to identify patterns that can lead to more effective injury prevention.

image courtesy of www.ABC-OF-SNOWBOARDING.com

Preview the 25th Anniversary & Annual Meeting of the Wilderness Medical Society, which will be held in Snowmass, Colorado July 25-30, 2008.

Splinting

2008-07-12T19:35:00Z

A recent edition of an urban EMT magazine has an article on splinting that opens with a tale of a patient being transported with an un-splinted ankle fracture, and a reference to a study where only 25% of patients with extremity fractures had their injuries splinted before arrival at the ER, and fewer had RICE therapy applied in the field to help manage pain. I’m not sure how representative the sample population of this study may be (it didn't clearly separate isolated injuries from urgent multiple trauma patients), but it is consistent with my experience that splinting does not receive the same attention in urban EMS that we give it in wilderness medicine.

One of the comments on the web version of this article said that most ambulance patients are on backboards, which serve as a splint. I disagree. Just the other day I took over care of a patient with an un-splinted open tib-fib fracture. This first response crew also thought the backboard was plenty of splint, and were focused on applying the gadgetry of modern EMS; electrodes, pulse ox, automatic BP cuff, IV. I splinted the leg.

Because we can care for patients for hours or days, and transport patients in difficult conditions, wilderness medicine providers know the value of a sound splint: padded, but not bulky or heavy; rigid; adjustable; with fingers/toes accessible for assessment; with the joints above and below long bone injuries and the bones above and below a joint injury immobilized. We know a splint can stabilize an injury and prevent further damage, and that combined with RICE, can be helpful in pain management.

This is basic first aid. It’s an important skill that is much appreciated in the wilderness but sadly sometimes a lost art in the urban world.