Wilderness & Environmental Medicine

Risk-taking Behavior in Skiing Among Helmet Wearers and Nonwearers

Lana Ružić, Anton Tudor — 2011-12-01

Objective: To examine differences in on-the-snow ski behavior between helmet wearers and nonwearers.Methods: The data were collected using a survey. Several tourist agencies helped in administrating the survey to the skiers during the 2008–2009 and 2009–2010 seasons. The survey consisted of multiple-choice questions. The subjects were asked to choose answers most suitable for their skiing style and preferred skiing technique, volume of off-piste skiing, readiness to use time measuring systems on the slopes, and group-skiing preferences, such as leading the group, beside the group, away from the group, etc. The Risk Index was then calculated for each subject.Results: The answers of 710 skiers (mean age 35.5, range 16–81 years) were analyzed. The predictive power for risk-taking behavior was tested for gender, age, educational level, level of skiing, years of skiing, and helmet usage. Younger age, male gender, higher skiing level, and helmet usage were used as independent predictors for the overall Risk Index (Power [1-β err prob] = 0.942). Significantly higher risk was assessed for the male helmet wearers while the results were not significant for the female helmet wearers. The male occasional helmet wearers were found to be the most prone to risky behavior. In female nonhelmet wearers, there was a significant decrease in risk-taking behavior with age but this was not true for female helmet wearers.Conclusions: For males under 35 years of age, helmet use is one of the factors influencing risk-taking on the slopes. This is demonstrated for occasional helmet wearers in particular.

Fighting in Thin Air: Operational Wilderness Medicine in High Asia

George W. Rodway, Stephen R. Muza — 2011-12-01

Objective: The current conflict in Afghanistan is the first major military action in which the United States and other North Atlantic Treaty Organization (NATO) forces have found themselves regularly engaged in combat at high altitudes. However, high altitude warfare is not a new concept in Asia by any means.Methods: This article will offer a short general historical review of high altitude warfare in Asia and then specifically address some of the operational challenges faced by troops carrying out missions at high altitude in the ongoing conflict in Afghanistan. Additionally, there will be discussion of evidence-based interventions being used to attempt to maintain optimal health of the warfighter at high altitude in this theater of operations.Conclusions: Years of research into how to alleviate the problematic nature of military operations in the high altitude environment has resulted in extensive risk management recommendations from the US Army, specifically aimed at preventing altitude-related casualties.

Recognizing Dangerous Snakes in the United States and Canada: A Novel 3-Step Identification Method

Michael D. Cardwell — 2011-09-30

The rapid and accurate recognition of dangerously venomous snakes following bites is crucial to making appropriate decisions regarding first aid, evacuation, and treatment. Past recommendations for identification of dangerous North American pit vipers have often required subjective determinations of head shape or relied on traits shared with some nondangerous species (elliptical pupils and undivided subcaudal scales). Heat-sensitive facial pits are diagnostic but require close examination of the dangerous head, and cephalic traits are useless when working with a decapitated carcass. Exclusive of cephalic traits, pit vipers north of Mexico can be recognized by the combination of keeled middorsal scales and undivided subcaudal scales. The order of colored rings is usually suggested to identify coral snakes in the United States, yet extension of the colored rings across the ventral scales must be added as an essential identifying factor to ensure elimination of all harmless look-alikes. A novel 3-step flow chart is presented that allows dangerous snakes in the United States and Canada to be recognized quickly and dependably without relying on cephalic traits. This process cannot be used in other countries, however, due to greater variability of these characteristics in snakes from other parts of the world. Finally, close examination of potentially venomous snakes is extraordinarily dangerous and steps to safeguard those making such observations are discussed.

Conduit Vessel Blood Flow During the Trek to Mount Everest Base Camp

Valerie Dumais, Patrice Nault, Alexander Tsertsvadze, Thomas L. Forbes — 2011-10-17

Objective: Hemodynamic changes in response to the hypoxic environment of high altitude are vascular bed-specific. The aim of the present study was to investigate diameter and blood flow changes in conduit vessels in response to hypobaric hypoxia.Methods: Eleven healthy subjects ascending Mount Everest to base camp participated in this study. Vessel diameter and blood velocity for brachial, carotid, common femoral, superficial femoral, and deep femoral arteries were measured by portable Doppler ultrasound. Blood flow was calculated from these values. Measurements were taken at sea level, at increasing altitudes on ascent to base camp (1310 m, 3470 m, 5330 m), and repeated on descent to lower altitude (1310 m).Results: For all vessels except carotids, both vessel diameter and blood flow decreased between sea level and initial ascent to altitude, with subsequent persistence of these decreased values; there was no further significant change with continued ascent to higher altitude. Blood flow for all arteries (except carotids) increased significantly on descent to lower altitude, with an associated nonsignificant increase in velocity and decrease in diameter.Conclusions: This study showed that there is vasoconstriction of limb conduit vessels at altitude, which persists upon descent to lower altitude. Blood flow in these vessels also decreases with initial exposure to high altitude, yet increases when returning to lower altitude, reflecting variations in blood velocity. Carotid arteries responded differently to the stimulus of hypobaria than limb conduit vessels; there was no change in diameter seen on ascent or descent, but there was a progressive decrease in blood flow on ascent, with no change on subsequent descent.

Improving Sleep at Altitude: A Comparison of Therapies

2011-10-10

Objective: This study aimed to compare 3 treatment modalities during sleep at an altitude of 5300 m to identify strategies for reducing the incidence of periodic breathing at high altitude.Methods: Fifteen trekkers, with identical ascent profiles and no signs or symptoms of altitude illness, served as subjects. All study participants arrived at 5300 m after a gradual ascent from 1300 m. On their second night at 5300 m, subjects were randomly assigned (with a computer-based random assignment procedure) to 1 of 4 different treatment groups: control (n = 4); 1 L/min O2 via a demand system during sleep (n = 3); 1 L/min O2/CO2 mix (1.5% CO2) via a demand system during sleep (n = 4); or 125 mg acetazolamide 30 minutes before bedtime (n = 4). Heart rate, respiration rate, blood oxygen saturation, tidal volume, minute volume, and apnea hypopnea index were measured.Results: Upon comparing the 4 groups, there were no statistically significant differences between the variables. One-way analysis of variance indicated a trend toward statistical significance for SaO2 between groups (F = 2.9, P = .08), and Tukey Honestly Significant Difference (HSD) post hoc tests indicated a trend in the SaO2 difference between the 1 L/min oxygen and control groups (P = .07). While 1-way analysis of variance suggested no difference for respiratory rate between groups (F = 2.5, P = .1), Tukey HSD indicated a trend in statistical difference of the respiratory rate between 1 L/min O2 and 1 L/min O2/CO2 mixture (P = .08).Conclusions: These statistical trends found between control and treatment groups indicate that further study is warranted.

The Effects of High- and Low-Dose Aspirin on Thermoregulation During and After Acute Cold Exposure

Leigh K. Murray, Ronald Otterstetter, Matthew D. Muller, Ellen L. Glickman — 2011-09-12

Objective: To explore the effect of aspirin on the thermoregulatory responses of men during exposure to 12°C air (acute cold exposure) for a period of 120 minutes and recovery in 25°C air (rewarming) for 120 minutes.Methods: Seven male subjects (26.1 ± 2.4 yr) underwent pre-experimental testing to determine peak VO2 and body composition. Participants underwent 3 trials in which they ingested the following for 1 week prior to each experimental trial: a capsule filled with cellulose (placebo), 81 mg · day−1 of aspirin (low-dose aspirin), or 650 mg · day−1 of aspirin (high-dose aspirin). Each trial consisted of a 30-minute baseline period, 120 minutes of exposure to 12°C air, and 120 minutes of recovery in 25°C air. Mean skin temperature and rectal temperature (Tre) were measured, and heat production was calculated.Results: During both acute cold exposure and rewarming, analysis of variance revealed a main effect for time (P < .05) with respect to Tre, mean skin temperature, and heat production. However, there were no significant differences between the treatments or treatment by time interactions.Conclusions: These data demonstrate that aspirin had no significant effect on the thermal and metabolic responses during acute cold exposure and rewarming.

Fatalities on Austrian Ski Slopes During a 5-year period

Gerhard Ruedl, Hanno Bilek, Hans Ebner, Karl Gabl, Martin Kopp, Martin Burtscher — 2011-10-10

Background: While the mean injury rate from snow sports in Austria is low (less than 2 injuries per 1000 skier days), there is little information about fatalities on Austrian ski slopes.Objective: The purpose of this study was to evaluate incidence and causes of fatalities among recreational skiers and snowboarders over a 5-season period on Austrian ski slopes.Methods: All traumatic and nontraumatic fatal ski accidents from the 2005-2006 through the 2009-2010 winter season were compiled by members of the Federal Ministry of the Interior. Data on age, gender, nationality, gear used, altitude, accident cause, primary cause of death, and helmet use were collected. The number of fatalities was related to a million skier days during this 5-year period.Results: In total, 207 fatalities were registered during this time period. An overall incidence of 0.79 deaths per million skier days was calculated. Mean age was 50.9 ± 17.7 years. More than 85% of all fatalities occurred in males and 93.1% in skiers. Mean altitude was 1706.1 ± 517.7 m above sea level. In total, 52.7% were nontraumatic deaths, with the majority (73%) attributed to cardiac arrest. Regarding traumatic deaths, 41.2% died after a fall, 18.6% after collision with another skier, and 35.1% after an impact with a solid object. Head injury was the primary cause of death in 46.4% of traumatic deaths.Conclusions: Death is a rare event in recreational winter sports on Austrian ski slopes. Nevertheless, awareness of potential risk factors and common dangers may impact snow riders' behavior and help reduce the incidence of on-slope fatalities.

A Blinded, Randomized, Palatability Study Comparing Variations of 2 Popular Field Water Disinfection Tablets

Jason D. Heiner, Emily A. Simmons, David C. Hile, Ian S. Wedmore — 2011-12-01

Objective: Halogen-based water disinfection tablets may render an unpleasant taste to treated water. Proposed safe additives such as ascorbic acid may reduce this objectionable taste. We compared the palatability of 2 field water disinfectants: iodine-based tetraglycine hydroperiodide (TGHP) and chlorine-based chlorine dioxide (CD) both with and without the concomitant use of an ascorbic acid taste neutralizer.Methods: Blinded participants randomly sampled 5 different distilled water samples containing combinations of disinfectant tablets and ascorbic acid: 1) water; 2) water with TGHP; 3) water with CD; 4) water with TGHP plus ascorbic acid; and 5) water with CD plus ascorbic acid. Participants rated beverage taste via a 100 mm visual analogue scale (VAS) and ranked the samples from “most pleasant” to “least pleasant.”Results: Sixty participants evaluated the samples. On the VAS, water with TGHP tasted worst and water with CD tasted second worst. Water with TGHP plus ascorbic acid, water alone, and water with CD plus ascorbic acid measured similarly as significantly best tasting. Water with TGHP was ranked by 58% as “least pleasant” tasting, while water with TGHP and ascorbic acid was ranked by 40% as “most pleasant” tasting.Conclusions: Participants found halogen-based disinfected water significantly less palatable prior to the addition of ascorbic acid. Addition of ascorbic acid to treated water created a beverage of similar preference to distilled water. These results may increase compliance with the use of disinfecting tablets by increasing the palatability of drinking water made potable via addition of ascorbic acid to halogen-based chemical disinfection.

Keeping Your Cool: A Case Study of a Female Explorer's Solo North Pole Expedition

Tracey J. Devonport, Andrew M. Lane, Juliette Lloyd — 2011-10-10

Objective: This study explored stress and coping experiences during a solo expedition to the North Pole using concurrent and retrospective methods.Methods: A 47-year-old female explorer, with 12 years of polar experience, completed a daily diary during the expedition. On return, 2 semistructured interviews were completed to identify the challenges and coping efforts perceived as being most pertinent during her expedition.Results: Inductive coding identified 4 broad stressors, including environmental conditions, personal challenges, supporting resources, and expedition progress.Conclusions: Findings highlight the importance of expedition preparation in establishing coping efficacy in managing the extreme demands placed upon polar explorers. Findings also evidence idiosyncrasies in the choice and application of coping strategies and, thus, highlight the need to avoid generalizations regarding coping outcomes.

Irukandji Sydrome in the Torres Strait: A Series of 8 Cases

2011-10-17

Objective: To review the presentations of a series of patients with suspected Irukandji syndrome in the Torres Strait, where the syndrome has hitherto been unknown or undocumented, in order to identify at-risk groups and improve the management of this condition in the region.Methods: A mixed retrospective-prospective review of eight cases of patients with suspected Irukandji syndrome in the Torres Strait, with a focus on the differences between the clinical presentations and patient outcomes.Results: Irukandji syndrome is the most likely explanation, based on current knowledge, of this series of marine envenomation syndromes in the Torres Strait. The syndrome appears to be more common in the monsoon season and young, Torres Strait Islander males likely represent a high-risk group in the region.Conclusions: The Torres Strait can be added to the growing list of regions where Irukandji syndrome has been documented. The clinical picture, including time to onset of symptoms, constellation of symptoms and signs, analgesic requirement and time to recovery, can differ markedly between patients. There is a need for health promotion and education of health staff and the public regarding the risks, symptoms and signs of this condition. There is also a clear need for the use of case definitions and standardised management approaches for Irukandji syndrome, while the health community awaits the results of ongoing research into the pathophysiology and improved treatments for this interesting but dangerous tropical marine envenomation syndrome.

Immune Responses to Exercising in a Cold Environment

Emily C.P. LaVoy, Brian K. McFarlin, Richard J. Simpson — 2011-10-10

Cold temperature and exercise independently impose stress on the human body that can lead to circulatory and metabolic changes, and depress the immune system. Multiple stressors applied together may amplify this immunodepression, causing greater immune impairment and heightened infection risk than with either stressor alone. As such, winter athletes and other persons who work or physically exert themselves in cold temperatures may have greater levels of stress-induced immune impairment than would be expected under mild temperatures. This review examines the literature regarding changes to physiological and immunological parameters arising from exposure to cold temperatures and to exercise. Even brief exposure to cold leads to increased levels of norepinephrine and cortisol, lymphocytosis, decreased lymphoproliferative responses, decreased levels of TH1 cytokines and salivary IgA, and increased lactate levels during exercise. Whether these changes lead to increased susceptibility to infection, as suggested by some epidemiological reports, remains to be determined. Although there is some evidence that exercising in temperatures near 5°C leads to greater immune impairment compared to exercising in milder temperatures, there is a need to explore the effects of exercise on immunity in the subfreezing conditions typically encountered by winter athletes. This is required to fully determine the extent to which performing vigorous exercise in subfreezing temperatures amplifies exercise-induced immune impairment and infection risk.

Because It's There … The Education of George Mallory

Rishi Madhok, Jay Lemery, George W. Rodway — 2011-12-01

Initiative, creativity, and resolve represent both the pillars of the Wilderness Medical Society (WMS) and the story of George Mallory. His journey from humble beginnings to his rise to become one of history's most legendary mountaineers is a testament to the impact of great mentors as well as the development of Mallory as a mentor himself. In this light, the path of George Mallory in mountaineering and the role of WMS in wilderness medicine share a common theme. This essay is not only a tribute to George Mallory but also a testament to the importance of mentorship and the role of WMS in inspiring mentorship and education to future pioneers.

The Epidemiology of Lift-Accessed Downhill Mountain Biking Injuries

Zachary Ashwell, Mary Pat McKay, Jeffery Brubacher, Annie Gareau — 2011-12-01

Lift-accessed downhill mountain biking has grown exponentially in popularity over the past decade. The sport, while offering participants access to a vast amount of terrain, also requires navigating steep and technical terrain at high speeds, posing significant risk of injury to the rider. A limited understanding of these risks impedes both medical management as well as industry-appropriate protective equipment development. The objective of this study was to describe the frequency and type of injuries sustained by downhill mountain bikers utilizing such lift-accessed bike parks.

Impact of Social, Political, and Cultural Factors on Care of an Unresponsive Patient during the December Riots in Port-au-Prince, Haiti

Ashley S. Bean — 2011-12-01

A 30-year-old unresponsive woman was cared for by a volunteer team of US medical professionals at the Partners in Development Clinic in Port-au-Prince, Haiti, during the December riots. Previously, she had been evaluated at the clinic for vomiting and had been given granisetron after lab results showed a normal urinalysis and blood glucose level and a negative pregnancy test. The day she re-presented, her family called the clinic because the patient lost consciousness and had a possible seizure after arguing with her husband. A medical team dispatched to the patient's tent village found that she had stable vital signs, reactive pupils, no signs of trauma, and a blood glucose level of 120 mg/dL; however, she was unresponsive to painful stimuli. Once at the clinic, she underwent a more complete evaluation, including a negative malaria test. At this point, the clinic's limited resources were exhausted but, due to armed rioters, the patient could not be transported to a local hospital. After the patient remained unchanged during the night, her husband visited a voodoo priest who cast a spell to aid the patient. One hour later, the patient awoke, interacted normally with her family, and left the clinic ambulatory.

Morbidity and Mortality in US National Parks: A Review of National Emergency Medical Services Workload from 2007 to 2009

Matthieu P. DeClerck, Laurie M. Atterton, Thomas Seibert, Tracy A. Cushing — 2011-12-01

Outdoor recreation is growing in the United States with over 278 million annual visitors to areas controlled by the National Park Service (NPS). The National Park rangers oversee emergency medical needs in these parks. This study examines medical and traumatic emergencies throughout the National Parks over a 3-year period to better understand events rangers encounter, types of fatalities, and automated external defibrillator (AED) usage on a national scale.

Ocular Myiasis During an Amphibious Military Exercise in Djibouti

Kurt P. Eifling, Joseph W. Diclaro — 2011-12-01

In November 2010, a healthy 27-year-old active duty US marine presented to the Battalion Landing Team 3/8 Battalion Aid Station located, at the time, on a beach in the East African nation of Djibouti. His chief complaint was of a foreign body sensation in the right eye, reporting that a bug had flown into the eye 8 hours prior. He denied further symptoms. Physical exam revealed multiple 1 to 2 mm larvae moving vigorously on the conjunctiva of the affected eye, confirming the diagnosis of ocular myiasis. The patient's eye and its maggots were anesthetized with 0.5% tetracaine ophthalmic drops, and a total of 15 maggots were collected manually using cotton-tipped applicators. Antibacterial prophylaxis was given with topical moxifloxacin drops and erythromycin ointment. Slit lamp and fluorescein exams were normal after the procedure. Treatment was stopped after 3 days and the patient had no complications.

Acute Anxiety Among Marines After Recent Arrival at High Altitude: High Altitude Anxiety as a Distinct Diagnostic Entity

Jeffrey H. Gertsch, Erik Virre, Michael K. Sracic, Allen Pate, Darren Thomas — 2011-12-01

As United States and allied armed forces maintain a presence in high altitude regions such as eastern Afghanistan, a better understanding of the prevention, diagnosis, and treatment of altitude illness has become increasingly important. This preventable form of disease/nonbattle injury presents a significant issue to readiness for warfighter performance in the field.

Exercise-associated Hyponatremia is Common Among Dehydrated 161 Kilometer Ultramarathoners

Martin D. Hoffman, Tamara Hew-Butler, Kristin J. Stuempfle, Ian R. Rogers — 2011-12-01

Previous work has demonstrated that exercise-associated hyponatremia (EAH) rarely occurs in association with dehydration and that there is a significant negative relationship between post-race serum sodium concentration (Na+) and weight change. In other words, EAH has been found to occur more often when there is weight gain rather than weight loss during the event. This has been in contrast to our observations from 161 km ultramarathon races in northern California. The present work consolidates our findings from studies at three 161 km ultramarathons in northern California.

Wilderness Medicine Within Global Health: A Strategy for Less Risk and More Reward

Amita A. Kulkarni, Liz B. Francis, Jay M. Lemery, Dana L. Sacco — 2011-12-01

A Case Study of Integrating the 2 Disciplines at Weill Cornell Medical College Over the last decade, there has been a growing interest in global health among medical students. According to the Association of American Medical Colleges, 45 US medical schools offer a Global Health component, with 29.9% of graduating students stating they have had “global health experience.” With an emphasis on self-reliance and the delivery of medical care in austere and unpredictable environments, we advocate that wilderness medicine (WM) skill sets are an integral component of global heath, mitigating risk to students and empowering them to be safe as they participate in this rapidly evolving field. Our objective was to examine ways in which WM topics can be incorporated into global health coursework, and the benefits that come from this integration.

A Prospective Cohort Study of Acute Kidney Injury in Multi-Day Ultramarathon Runners

2011-12-01

Ultramarathon foot races of distances greater than the traditional 26.2 mile marathon are increasing in popularity, attracting more than 70 000 annual participants worldwide. Prior studies have consistently documented renal function impairment, but only after race completion. The incidence of renal injury during these multi-day ultramarathons is currently unknown. This is the first prospective cohort study to evaluate the incidence of acute kidney injury (AKI) in runners during a multi-day ultramarathon foot race.

Who is Being Rescued in Canadian National Parks?

Jonathan A. Malo, Eiman Zargaran — 2011-12-01

There has been a growing body of literature reviewing the epidemiology of injuries, illnesses, and search and rescue (SAR) operations in National Parks in the United States. There are 42 National Parks in Canada that experienced over 12 million visitors in 2010. Little research has been published to date on SAR trends in Canadian National Parks.

Injury and Illness on the West Coast Trail: Still the graveyard of the Pacific?

Jonathan A. Malo, Eiman Zargaran — 2011-12-01

The West Coast Trail (WCT) is a 75 km trek in Pacific Rim National Park Reserve on the southwest coast of Vancouver Island, British Columbia, with 4000 to 6000 hikers attempting to complete the trail annually. It is a physically demanding and strenuous hike renowned for its unique infrastructures and violent weather. Parks Canada quotes that 1% to 2% of hikers require evacuation every year, while an additional 200 sustain minor injuries. There is growing literature reviewing injuries and illnesses in US National Parks that consistently show hikers to be the most common group requiring medical assistance. To date, no formal studies have analyzed the morbidity associated with a specific hike where accurate census data is available.

Impact of Handheld SONAR Devices on SCUBA Diver Rescue

Owen McGrane, Aaron Cronin, David Hile — 2011-12-01

To investigate if a handheld sound navigation ranging (SONAR) device significantly reduces the median duration to locate a missing diver. A secondary objective is to determine the effect a rescue adjunct has on the participant's confidence in performing a search for a missing diver.

Implications of Parental Influence on Child/Adolescent Helmet Use in Snow Sports

Aaron J. Provance, Glenn H. Engelman, Patrick M. Carry — 2011-12-01

Helmets have become increasingly more important with the advent of extreme snow sports, including skiing and snowboarding. Despite proven benefits, the rate of helmet use is less than ideal. The objective of this study was to describe the factors that influence helmet use among children who participate in skiing and/or snowboarding.

High Altitude Cerebral Edema Strikes a 26-year-old Male Corpsman after 18 Hours at Approximately 3110 m: Correlation of Objective and Clinical Findings

Gregory Ulrich, Darren Thomas, Erik Virre, Jeffrey H. Gertsch — 2011-12-01

A 26-year-old male Marine Corps Corpsman experienced high altitude cerebral edema (HACE) at a relatively low altitude (3110 m). His case and its significance are discussed. The individual was participating in a Mountain Medicine training course at the Marine Corps Mountain Warfare Training Center (MWTC) in Bridgeport, California, and had agreed to participate in a prospective observational study looking for objective biomarkers of hypobaric hypoxia. Informed consent was obtained and baseline testing (optic ultrasound, blood labs, and the Lake Louise Acute Mountain Sickness [AMS] Survey) was performed the night before ascent (2061 m). The participant ascended to 3110 m on training day 2. Routine monitoring by training staff at approximately 15 hours post-ascent (at approximately 01:00 hours) revealed the participant to be in obvious distress, complaining of a severe pulsating headache associated with nausea and photophobia/phonophobia (his “usual” headaches never included photophobia/phonophobia), as well as fatigue, faint anxiety, and disrupted sleep. The course instructors suspected AMS and elected to move him to lower altitude (2061 m). Upon evaluation by MWTC medical staff, the patient disclosed a history of refractory headache and emesis requiring descent after summiting Pikes Peak, Colorado. A careful neurological examination revealed moderate encephalopathy and obvious truncal ataxia. The patient was treated with prednisone and studies were initiated (vitals/pulse oximetry, basic chemistries, chest radiograph, optic ultrasound), and the patient was evacuated to higher-level care for an MRI of the brain, electroencephalogram, and a lumbar puncture. The final clinical diagnosis remained HACE.

Case Report: Simple and Effective Field Extraction of Human Botfly Using a Snake Venom Extractor

Jonathan K. West — 2011-12-01

Two weeks following a trip to Belize, a 25-year-old male noticed an erythematous lesion on his upper left chest, which enlarged over a 6-week period and formed a central punctum with a small opening in the skin. The patient reported feeling movement and intermittent lancinating pains under the skin. The patient's exam and symptoms were consistent with human botfly infestation, or cutaneous myiasis, secondary to Dermatobia hominis.

Emergency Medicine Resident-Run Wilderness Life Support Course Improves Confidence in Several Skill Areas of Wilderness Medicine Across Multiple Levels of Medical Providers

Jenna M.B. White, Kathleen D. Moorhead, Benjamin S. Bassin — 2011-12-01

This study was designed to evaluate changes in comfort level with specific wilderness skills before and after an Advanced Wilderness Life Support (AWLS) course. This is a retrospective study involving 38 participants who completed AWLS. The course occurred August 21 to August 22, 2010 and was hosted by the Austere Environment Medical Initiative through the University of Michigan. The course design included 12 didactic lectures as well as small group learning and hands-on skill sessions. Prior to the course, participants answered a short survey questioning their comfort levels with various wilderness medical skills. The scale ranged from 1 (least) to 5 (most) comfortable. At the conclusion of the course, prior to the final exam, participants took the same short survey and rated their comfort levels again with the same skills. Skills assessed included: patient assessment, evacuation, orthopedic injuries, heat and cold illness, altitude illness, avalanche rescue, lightning injuries, infectious diseases, and expedition medicine. Additionally, a final survey was emailed to participants 1 month after the conclusion of the course. Results were analyzed with the Student's t-test and indicated that comfort levels significantly improved after the course across all skills assessed.

Visual Side Effects of Scopolamine/Dextroamphetamine Among Parabolic Fliers

2011-12-01

The authors of this experimental study sought to test the operational effects of scopolamine and dexamphetamine by testing near vision, accommodation, and pupil size. Scopolamine (0.4 mg) and dexamphetamine (5 mg) has been used as an oral medication to treat motion sickness. With a peak onset of 1 hour, the scopolamine improves symptoms of nausea while suppressing the parasympathetic nervous system. Side effects include drowsiness, which is opposed by the dexamphetamine, cycloplegia, and mydriasis.

Intravital Pathophysiologic Comparison of Frostbite and Burn Injury in a Murine Model

2011-12-01

The authors of this experimental study tested a murine model using heat and cold injury that did not involve direct contact in order to compare cellular changes between each mechanism. Forty mice were anesthetized while their body temperatures were maintained at 37°C. Their ears were stretched in a similar fashion and exposed to 117°C air for 1 second at a distance of 1 mm or −196°C liquid nitrogen for 1.5 seconds at a distance of 3 mm. Fluorescent microscopy was used to compare cellular changes between each model prior to injury and at day 1, 3, 7, and 12.

Video Calls for Dispatcher-assisted Cardiopulmonary Resuscitation Can Improve the Confidence of Lay Rescuers—Surveys After Simulated Cardiac Arrest

2011-12-01

The authors of this survey study used a randomized control design to assess participants' responses to dispatcher direction of cardiopulmonary resuscitation (CPR) through audio and video modalities. It was their hypothesis that video-assisted CPR would be better than only audio. A total of 180 students participated in the study and filled out post-study surveys that were used to assess each technique. These students, whose average age was 18 years, were randomized into a video-assisted group and an audio-assisted group. An experienced dispatcher, who was also randomized, directed the students through a simulated cardiac arrest requiring CPR on a manikin. Post-CPR surveys suggested that the students who used video were more certain of the correctness of their CPR (49% vs 30%). Though this study was limited by its survey design and the absences of an outside rating of student CPR, it is my belief that it discusses a potentially important avenue to treatment of emergencies in remote areas.

Epidemiology and Outcomes of Poisoning-induced Out-of-hospital Cardiac Arrest

2011-12-01

This retrospective chart review focused on a Korean population of out-of-hospital cardiac arrests (OHCA) in order to define epidemiologic factors related to outcome when poisoning was the causative factor. Data were collected from a registry of OHCA recorded by the Korean EMS system between 2006 and 2008. Available demographics included initial rhythm, presence of bystander CPR, witness involvement, treatments rendered by EMS, response time, and pre-hospital time. Poisoning cases were determined by physician report, history from witnesses or EMTs, or clinical symptoms. Poisons were classified into pesticides (insecticides, herbicides, or other), nonpesticides, and unknown.

Simple Derivation of the Initial Fluid Rate for the Resuscitation of Severely Burned Adult Combat Casualties: In Silico Validation of the Rule of 10

2011-12-01

The authors suggest that initial burn resuscitation is made difficult by using existing American Burn Association (ABA) guidelines recommending the Parkland or modified Brooke formula (2 to 4 mL of lactated Ringer's [LR] solution per hour multiplied by the patient's body weight and percentage of total body surface area [TBSA] burned, where half is given over the first 8 hours and the other half over the remaining 16 hours). They offered an alternative formula—one that they believed to be easier to remember—and used a computer model to compare it with ABA guidelines. The “rule of 10” predicts an initial fluid rate (in mL of LR/h) equal to the percentage of TBSA estimated to the nearest 10 and multiplied by 10 for patients between 40 and 80 kg. For every 10 kg above 80 kg, 100 mL/h should be added. For example, a 50% TBSA burn would be initially resuscitated with 500 mL of LR/h.

In Response to “Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Frostbite”

Ken Zafren — 2011-10-10

I would like to congratulate the authors of the Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Frostbite for their review of the literature and for their recommendations. While most of their advice is excellent and is based on the best available evidence, there are a few controversial areas that might benefit from further illumination.

In Reply to Dr Zafren

2011-12-01

We thank Dr Zafren for his insightful comments and questions. We acknowledge that the Frostbite Guidelines are not an exhaustive treatise, but are recommendations from a group of subject matter experts after review of the most relevant frostbite literature. They are intended to be concise so that practitioners can access pertinent clinical and treatment information quickly and easily.

In Response to Bradford Washburn's 1962 NEJM Article “Frostbite: What It Is—How To Prevent It—Emergency Treatment”—Historical Background and Commentary

Ken Zafren — 2011-10-17

I read with interest and alarm Bradford Washburn's 1962 NEJM Article “Frostbite: What It Is—How To Prevent It—Emergency Treatment”—Historical Background and Commentary by Rodway et al. Some of the lessons from this “Lessons in History” were not those intended by the authors.

In Reply to Dr Zafren

George W. Rodway, Scott E. McIntosh, Eldon Wayne Askew — 2011-10-10

We would like to thank Dr Zafren for his letter regarding our historical treatment of Bradford Washburn's 1962 New England Journal of Medicine article on frostbite. The information Dr Zafren relates is not common knowledge among the general scientific community, and the Alaskan views he expresses regarding this 1962 article are most fascinating. Medical history is not usually spiced with controversy, but differing interpretations are what, at times, make the pursuit of history particularly interesting and worthwhile. However, there are a few points to which we feel we should respond.

Ken Zafren — 2011-10-03

If you dream of adventure in frozen landscapes, this book may be for you. However, this coffee table book is not for everyone. It is written in French, German, and English, but not in the usual manner of books in 3 languages. There is parallel text in only a few places. Those who don't read all 3 languages will have to content themselves with looking at the photos in many of the chapters. The entire book is well-illustrated, although most of the images are of horizontal white landscapes with and without camps or warmly clad people. There are also some photos of polar bears, gear, and settlements.

Outside Kathmandu

Mikel Vause — 2011-10-17

On August 23, 2010 a plane carrying 11 passengersfrom Kathmandu to Lukla crashed in heavy rains. What draws us

Wilderness Images

Cory Fieldling — 2011-12-01

Wilderness Images

Jonathan Conard — 2011-12-01

Wilderness Images

Cory Fielding — 2011-12-01