Wilderness Medicine

Auto-Injector Safety

2010-08-24T16:28:00Z

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I recently received a credible email account of a person with WFR training accidently discharging an auto-injector of epinephrine into their thumb. Thankfully, the thumb, and the patient who really needed the epinephrine are fine. The anecdote is a reminder that these devices are not foolproof. We need to learn how to use them properly, periodically refresh our knowledge and have the presence of mind to use them correctly.

A recent issue of the Journal of Allergy and Clinical Immunology has a paper describing self-reported unintentional injections from auto-injectors. They found 15,190 reports from 94-07 and a trend of increasing reports paralleling the increasing popularity of these devices. This number caught my attention.

The study is unable to tell us whether these injections harmed the patient; we do know that very few of these incidents sought medical care. We don't know how they happened, although errors during injection, during disposal of a fired device, training mishaps and reaching into a bag or purse to get the auto-injector are mentioned.

There are also reports in the medical literature that a disturbing number of people leave the doctor’s office and the pharmacy with inadequate instruction, unable to properly use their auto-injector. (BMJ 2003, J Allergy Clin Immunol 2000.)

There are at least three models of auto-injectors available; the Twinject and the classic and the newer version of the EpiPen. If you carry one of these for personal use, or might have to assist someone to use their personal auto-injector, it’s a good idea to make sure you know how and when to use the device.

Take care

Tod Schimelpfenig

Curriculum Director

Wilderness Medicine Institute of NOLS

Voluntarily reported unintentional injections from epinephrine auto-injectors. J Allergy Clin Immunol 2010;125:419-23.)

Injury and Illness Encountered in Shenandoah National Park

2010-08-09T03:27:00Z

This article by John Forrester and Christopher Holstege from the December 2009 edition of Wilderness & Environmental Medicine published by the Wilderness Medical Society presents an excellent model for understanding the most common types of illnesses and injuries that occur in a backcountry setting. Understanding these trends is extremely helpful for preparing staff to handle what they most likely will encounter in the field.

"The most common traumatic injuries necessitating a case incident report occurring in visitors to Shenandoah National Park are lower extremity soft tissue injuries and lacerations incurred while hiking. This pattern of adult trauma has now been found to be consistent among several geographically different National Parks in the United States and represents an injury pattern that all wilderness/outdoor care providers need to be competent to treat. The percentage of trauma victims under the age of 18 years as well as the patterns of traumatic injury that they experienced are similar among geographically distinct parks. In addition, the medical illnesses persons under the age of 18 years experience are similar. Knowing that trauma injury patterns are relatively similar but that medical illness is more locale specific can help health care providers tailor their resource allotment and health management protocols to their particular areas of care."

You can read the entire article online or download a PDF version.

Studies Show that Continuous Chest Compression CPR Very Effective

2010-08-01T02:11:00Z

Tod Schimelpfenig first reported on 'Hands-Only CPR' here in the Wilderness Medicine Blog back in 2008. Two studies just released in the July 2010 edition of the New England Journal of Medicine show that in many cases Compression Only CPR results in similar patient survival rates as Compression and Rescue Breathing CPR. This is especially important in situations where untrained people are giving CPR (or are being coached by 911 dispatchers.

The first study, CPR with Chest Compression Alone or with Rescue Breathing reported "analyses showed a trend toward a higher proportion of patients surviving to hospital discharge with chest compression alone as compared with chest compression plus rescue breathing for patients with a cardiac cause of arrest and for those with shockable rhythms."

In the second study, Compression-Only CPR or Standard CPR in Out-of-Hospital Cardiac Arrest the results "showed no significant difference with respect to survival at 30 days between instructions given by an emergency medical dispatcher, before the arrival of EMS personnel, for compression-only CPR and instructions for standard CPR in patients with suspected, witnessed, out-of-hospital cardiac arrest."

It should be noted that compression-only CPR is primarily focused on witnessed arrest scenarios and is not for infants or children and is not recommended in situations such as near-drowning, respiratory failure or drug overdose where rescue breathing is a necessary component.

One of the major sites for this research has been the University of Arizona. The press release that follows expands on their research into this issue. Additional information is available at NPR or you can listen to the NPR Podcast from the link at the bottom of this Blog. You can also watch the Continuous CPR Video from the University of Arizona.

Cardiac Arrest Resuscitation: Passive Oxygen Flow Better than Assisted Ventilation

Arizona researchers have added another piece to the mounting body of evidence that suggests during resuscitation efforts to treat patients in cardiac arrest, “passive ventilation” significantly increases survival rates, compared to the widely practiced “assisted ventilation.”

The study, published in an online edition of Annals of Emergency Medicine, compared the numbers of patients who had suffered a cardiac arrest outside a hospital setting and were resuscitated in the field by Emergency Medical Services personnel. Rescuers used either bag-valve-mask ventilation, which forces air into the patient’s lungs, or facemasks with a continuous flow of oxygen, which work in a similar fashion to those carried on airplanes in case the cabin pressure drops.

Among the 1,019 adult out-of-hospital cardiac arrest patients in the analysis, 459 received passive ventilation and 560 received bag-valve-mask ventilation. Neurologically normal survival after witnessed cardiac arrest with a shockable heart rhythm was higher for the passive oxygen flow method (38.2 percent) than bag-valve-mask ventilation (25.8 percent).

“These results are strikingly similar to earlier observations from Wisconsin, where survival rates went up from 15 percent to 38 percent after paramedics abandoned the official guidelines for the modified protocol that we developed,” says Gordon A. Ewy, MD, a co-author of the study and director of the Sarver Heart Center at The University of Arizona College of Medicine. The Sarver Heart Center’s Resuscitation Research Group developed a modified protocol for treating out-of-hospital cardiac arrest called Cardiocerebral Resuscitation, as opposed to Cardiopulmonary Resuscitation, which should be reserved for respiratory arrest (such as near-drowning or drug overdose).

Under the new concept, first tested in Wisconsin, EMS personnel no longer intubated the patient for ventilation. Instead, they applied a facemask delivering a continuous, low-pressure flow of oxygen.

“Our findings provide compelling evidence that positive pressure ventilation is not optimal in the initial management of out-of-hospital cardiac arrest,” says lead author Bentley Bobrow, MD, emergency physician at Maricopa Medical Center in Phoenix and associate professor of emergency medicine at the UA College of Medicine. “The work from our EMS providers in Arizona further questions the longstanding dogma of tracheal intubation and ventilation for cardiac arrest.

“We are most pleased that while we are helping to advance the science of resuscitation, we are saving more victims of cardiac arrest in Arizona than ever before,” adds Dr. Bobrow, who also is the medical director for the Arizona Department of Health Services Bureau of Emergency Medical Services.

“This study reinforces our belief that survival of out-of-hospital cardiac arrest has more to do with circulating the blood through quality and uninterrupted chest compressions than with ventilation,” Dr. Ewy adds.

EDITORS PLEASE NOTE:
A full-text pdf of the study published in Annals of Emergency Medicine, “Passive Oxygen Insufflation Is Superior to Bag-Valve-Mask Ventilation for Witnessed Ventricular Fibrillation Out-of-Hospital Cardiac Arrest,” is available at http://www.sciencedirect.com using the search terms “passive oxygen insufflation” and “Bobrow.”

More information about Cardiocerebral Resuscitation is available at http://www.heart.arizona.edu

Wilderness Medical Society Meeting WFA Discussion

2010-07-26T16:54:00Z

On Sunday evening July 25^th Tony Islas MD, president of the Wilderness Medical Society (WMS) hosted a meeting of wilderness medicine providers at the summer meeting of the WMS. All of the major providers were represented, including the Red Cross and members of ski patrol, representatives from AORE and WEA, Todd Minor from Cornell, the military and people just interested in local wilderness medicine education and a lively discussion. It was a great turnout of people and a pivotal evening for wilderness medicine.

Tony spoke of the role of the WMS in wilderness medicine education, and his desire that the society serve as a forum for discussion and a source of expertise for the industry. I’m excited about this agenda. We are the educators of the lay public and outdoor professionals. An active line of communication between the wilderness medicine instructor and the society will be a good thing–enhancing consistency and quality. He stated that the society is not interested in developing or endorsing a specific curriculum, in program accreditation or instructor credentialing. They do want to take the Scope of Practice documents our working group has developed and publish these as consensus position statements in the Journal of Wilderness and Environmental Medicine. It’s a sound endorsement of our work and will make the document available in the medical literature.

We have some more work to do incorporating feedback we have received, especially some thoughtful comments from AORE. We’ll have one more chance for anyone interested to comment in the months ahead. We’ll then craft the SOP’s into publishable form.

We’ve been asked about program accreditation, instructor credentialing, consistent certification lengths and quality assurance. These may be issues we want to address down the line, but first things first. Let’s get these SOP’s done.

Tod Schimelpfenig
Curriculum Director
WMI of NOLS

Consensus Altitude Guidelines

2010-06-27T01:31:00Z

Folks

The Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for prevention and treatment of acute mountain sickness, high altitude cerebral edema and high altitude pulmonary edema. These recommendations are published in the current edition of the Wilderness and Environmental Medicine Journal (Vol 21 (2), 146-155, 2010). This is the first in what I expect will be a series of consensus statements addressing wilderness medicine practices. While written for physicians and including prescription medication advice that is beyond the scope of practice of lay first aid providers, there are some sound evidence based recommendations supporting the common practices for prevention through gradual ascent and treatment with descent. I don’t read any significant changes from current recommendations or from what is commonly taught in reputable wilderness medicine courses.

You can access the article here: wemjournal.org/.

Take care

Tod Schimelpfenig
Curriculum Director
Wilderness Medicine Institute of NOLS

WFR Scope of Practice Draft

2010-05-21T15:26:00Z

The group of wilderness medicine providers working on scope of practice documents have completed a draft of a Wilderness First Responder (WFR) Scope of Practice (SOP) Guideline to accompany the Wilderness First Aid (WFA) SOP published last fall. We’re circulating the WFR SOP draft to provide an opportunity for public comment

In 1999 a number of prominent wilderness medicine course providers made copies of their curriculum available and participated in a discussion that resulted in the Wilderness Medical Society Wilderness First Responder Recommended Minimum Topic List. ¹ This has remained the most prominent published document defining the WFR. David Johnson MD of Wilderness Medical Associates and I have been talking for several years about curriculum consistency in wilderness medicine. We decided in the winter of 2009 that it was time to move forward on this question and to approach this project by first defining what a WFA and WFR should know and what they should be able to do, their “scope of practice.”

It’s not a curriculum, set of lesson plans or supporting text. There are plenty of these available to those who wish to teach. We have no enforcement ability or agenda and our work is non-binding. We do hope it sets some boundaries and clarifies these credentials.

The process of circulating and discussing drafts among the working group has been educational and collegial. We don’t all agree on every detail of the document - we’re a bunch of opinionated medical geeks - but we have been able to achieve a consensus.

The field of wilderness medicine has been accused of designing courses without any basis in medical evidence. I disagree. There is evidence, and we use it.² Granted, much of it is tradition, expert opinion or educated guess, but this “level of evidence” abounds in first aid. Good science on whether a technique actually changes the outcome is often lacking, especially in a wilderness context. We have to extrapolate an urban study to the wilderness. We have to use our experience, as biased as it may be. We’re well aware of the ongoing arguments over the effectiveness of various first aid skills. The SOP reflects our distillation of this material into a set of practical and relevant skills that we can reasonably expect a lay medical provider to perform in the field and that will help, and not harm the patient.

One of the challenges of wilderness medicine is the many different contexts of practice. Hikers and paddlers will have different injury/illness profiles, as will adventure racers, outdoor programs and rock climbers. There are consistent themes; soft tissue and athletic injury, flu-like and GI illness are common. We also know we carry our medical history with us, and that people can have cardiac, respiratory and other medical events in the wilderness. The SAR reports show us the rare severe injury events. Those who argue that wilderness leaders need only rudimentary medical skills don’t appreciate this breath of need.

Our focus is on the first aid. Of greater importance are the fundamental outdoor skills, leadership and judgment that are the foundation of prevention and ultimately more powerful medicine that the first aid we can practice in the wilderness.

We’ll gather input through the summer and meet at the Wilderness Medical Society meeting in Snowmass in July to discuss next steps. I’m asked whether a standard curriculum or wilderness medicine program and instructor accreditation are next. I don’t know. I do know, as Steve Donelan wrote recently in the WEM Journal, “Even an evidence based, standardized curriculum cannot guarantee that students will learn. Whether our classes are effective in preparing students for real emergencies still depends more on how we teach than on what we teach.”³

Wilderness Medical Society Curriculum Committee. Wilderness First Responder: Recommended Minimum Course Topics. Wilderness & Environmental Medicine, 10, 13-19.1999.
Islas T. What kills us in the woods. Syllabus, 25th Annual Meeting of the Wilderness Medical Society. Snowmass, CO.; July 2008,
Donelan S. Classroom and Reality: What Should We Teach in Wilderness First Aid Courses? Wilderness & Environmental Medicine, 21, 64–66 (2010)

Bacterial Diarrhea

2010-05-03T01:04:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

Foodborne bacterial diarrhea is a common problem of backpackers, kayakers, divers - of anyone who ventures into the outdoors and is therefore associated with ingestion of fresh fruits and vegetables, travels to developing countries, practices inadequate hygiene, or even dines in public restaurants. Diagnosis and treatment of infectious diarrhea (bacterial, protozoal, viral, and other causes) is an essential skill for the wilderness medicine practitioner.

In an article (New England Journal of Medicine 2009;361:1560-1569) entitled "Bacterial Diarrhea," my good friend Dr. Herbert DuPont of the University of Texas School of Public Health and the Baylor College of Medicine provided a phenomenal update on the topic. There is a wealth of information in the article, so I will hit a few of the facts and figures that should be of greatest interest to this particular readership.

Campylobacter, nontyphoid Salmonella, Shiga toxin-producing E. coli, and Shigella bacteria are common causal agents of bacteria-induced diarrhea in the U.S. Other bacteria are more frequently associated with particular environments, such as Aeromonas in tropical regions. Plesiomonas shigelloides is associated with seafood ingestion and international travel.

The article was U.S.-focused. Acute watery diarrhea should bring to mind E. coli, Salmonella and Campylobacter. Bloody diarrhea ("dysentery") is suggestive of colitis. The four major U.S. causes, in descending order, are Shigella, Campylobacter, nontyphoid Salmonella and Shiga toxin-producing E. coli.

Food poisoning is the term used when a preformed toxin in good is eaten, which causes intoxication rather than an infection. A common culprit is Staphylococcus aureus. Others are Clostridium perfringens and Bacillus cereus.

Traveler's diarrhea can be caused by many different bacteria, but the most common is E. coli. Persons with traveler's diarrhea may be treated empirically with antibiotics without having their stool examined under the microscope or by stool culture. To prevent the disease, rifaximin in a dose of 200 mg once or twice a day taken with major meals while in the affected area appears to be effective. Indications for prophylaxis include an important trip, underlying illness that might be worsened by the disease, condition in which someone might be more prone to diarrhea, or suggestion that a person has increased susceptibility for some other reason.

Treatment recommendations are discussed. For all cases of diarrhea, attention to fluid and electrolyte replacement is essential. A diet of easily digestible food or a diet of bananas, rice, applesauce and toast is often recommended, but there is no evidence that such diets hasten recovery. It is important to keep the victim hydrated and nourished as best possible, which supports the concept of oral feeding. Drugs that diminish the number of bowel movements, such as loperamide, may be helpful. If the victim suffers from fever or dysentery, then antimotility drugs should only be used in combination with antibiotics.

This is an important and comprehensive review article for anyone interested in bacterial diarrhea. There are complete antibiotic recommendations, lists of complications, and discussion of areas of uncertainty. While the article is written for doctors, it has much information that can be understood and used effectively by laypersons.

Evolving Snake Venom

2010-04-19T02:56:00Z

Have you heard the story of evolving snake venom? Apparently snake venom in general is becoming more potent and, gasp, snakes have been interbreeding and sharing potent neurotoxins. Alas, while this is good stuff for horror movies, it’s not yet been scientifically demonstrated and probably isn’t true.

There were several media articles in 2009 describing the increasingly potent snake venom. Since then I've been asked a number of times about this concept, and have listened to people state this as a fact. There is an article in the most recent Wilderness and Environmental Medicine (WEM) Journal that discusses this question in depth.

According to the authors, both very reputable snakebite researchers, it's only speculation that snake venoms are quickly evolving, or becoming more toxic.

The concept that snakebites are becoming worse has not been demonstrated in the medical literature. The perception that they are worse can be influenced by media drama, especially 'real-life' television drama or the dramatic images of a few isolated bites that circulate on the internet. The WEM paper describes how an isolated case report became media drama when opinions of experts who questioned the hypothesis of rapidly evolving venom were not included in the lay press articles.

Venom composition and toxicity varies within populations of the same species of snake, which may account for the different s/s and an illusion of evolution. If the average envenomation is indeed becoming more severe, the paper offers several other possible explanations including larger snakes, more provoked bites, and the difficulty of comparing severity in the face of changing snakebite treatment protocols over the years.

I've heard that the Mojave rattlesnake is interbreeding with other populations and spreading it's neurotoxin around. This has not been demonstrated. The "Mojave neurotoxin" has been identified in some isolated Southern Pacific rattlesnake populations, but these are not near populations of Mojave rattlesnakes. It may well be that we are simply getting better at identifying the many toxins in snake venom.

The article also discussed the pace of evolution, which doesn't match the rapid changes supposedly happening.

So, we don't know if venom is rapidly evolving or becoming more potent. We do know we are always vulnerable to the dramatic story, especially if in involves snakes, spiders or other creepy crawlers.

Take care

Tod

Hayes W and Mackessy S. Sensationalistic Journalism and Tales of Snakebite: Are Rattlesnakes Rapidly Evolving More Toxic Venom? Wilderness and Environmental Medicine, 21, 35-45 (2010)

Raynaud's Phenomenon and Altitude

2010-03-22T03:22:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

In a past issue of Wilderness and Environmental Medicine (Volume 20, Number 2, 2009), Andrew Luks and colleagues published an article entitled “Can People with Raynaud’s phenomenon Travel to High Altitude?” The purpose of their inquiry was to determine whether high altitude travel adversely affects mountain enthusiasts with Raynaud’s phenomenon (RP).

RP is constriction of tiny blood vessels in the fingers and/or toes after exposure to cold or an emotionally stressful situation. The initial appearance is one of severely blanched (whitened) or bluish skin, often with a sharp “cut-off” margin in the midportion of the digit(s). This is caused by decreased circulation. The episode ends with vigorous reflow of blood into the digit, which causes it to become warm and reddened. This phenomenon is different and much more pronounced than the normal mottling or diffuse and persistent discoloration sometimes seen in hands and feet exposed to cold. RP is usually symmetrical, involving both hands or both feet, and is usually apparent in sufferers by the age of 40 years. Because RP can be associated with a number of underlying diseases or anatomic abnormalities, a first-time sufferer should seek medical evaluation. Prevention in the outdoors involves primarily protecting the hands and feet and keeping them warm, avoiding drugs that cause blood vessel constriction, and prohibiting tobacco use. Many drugs have been recommended at one time or another to treat RP, but at the currrent time the calcium-channel blockers (such as nifedipine) and drugs that block the sympathetic nervous system (which causes blood vessels to constrict) are most in favor as therapies for use outside of the hospital. Blood vessel dilators, such as nitroglycerin or niacin, have not been proven effective.

Volunteers with RP were recruited to complete an online anonymous survey, which addressed aspects of their RP and mountaineering activities. Eighty-nine percent of respondents engaged in winter sports, but only 22% reported changing their mountain activities because of Raynaud’s phenomenon. Only 12% used prophylactic medications to attempt to prevent or mitigate their RP. Fifteen percent of respondents reported an episode of frostbite following a RP attack at high altitude.

The conclusions were that motivated individuals with primary RP, employing various prevention and treatment strategies, can engage in different activities, including winter sports, at altitudes above 2440 meters. Frostbite may be common in this population at high altitude, and care must be taken to prevent its recurrence.

image courtesy of www.clevelandclinic.org

Wilderness First Aid Scope of Practice Update

2010-03-12T21:08:00Z

Folks

This is an update on the wilderness first aid scope of practice process and documents.

Our group of colleagues have been working steadily on these documents.We have circulated several drafts of the Wilderness First Aid (WFA) Scope of Practice document, considered the feedback we have received and are close to a final draft. We’ve also been working on a Wilderness First Responder Scope (WFR) of Practice document and have a solid working draft which the providers are reviewing.We hope to post this for review later this spring.

One of the challenges we face is balancing the needs of a large spectrum of students, from outdoor trip leaders to camp staff and non-institutional outdoor recreationists, with the length of the course and our ability to deliver the material effectively. A WFA is a basic and introductory course in wilderness medicine, yet we’ve been asked to teach GPS and survival skills, detailed emergency plans, improvised litters, and a wide variety of medical topics. The elder hostel argues for cardiac curriculum, the therapeutic program for mental health curriculum, the ocean-based program for marine toxins, the high latitude program for more on cold injury. Folks up north don’t want to hear about heat illness and folks down south don’t want to hear about frostbite.

Choices must be made. As we develop each SOP document, we consider the available medical evidence, input from a variety of sources including practitioners, educators, and consumers, and our collective experience as guides, trip leaders, medical providers and professional medical educators.

We have had many collegial and interesting discussions on what should or should not be included in the scope of practice of a WFA .It is easy to reach consensus on the majority of the content. We spend most of our time on the question of what should be core and what can be an elective skill or topic. There is a need to balance a clear minimum standard for this credential while providing some flexibility to meet individual program needs.

I’m excited that the Wilderness Medical Society (WMS) will consider publishing the scope of practice documents in a consensus position statement on wilderness medicine courses for laypeople. The WMS is writing a series of position statements on important issues in wilderness medicine. The first consensus statement, on altitude illness, will be published in the next edition of the Wilderness and Environmental Medicine Journal. A statement on frostbite treatment is also being developed. Tony Islas MD, incoming WMS President, has offered the WMS as a place to support periodic, perhaps annual or biannual, gatherings of wilderness medicine providers to discuss common issues and revise these documents as needed. I think this is an excellent forum for us to publish our work and continue our conversations. The consensus position statement brings the weight of the society to bear on this question, and it's very appropriate.

A copy of the most current WFA SOP is attached (see the attachment link below). We are still open to comments.

Take Care,

Tod Schimelpfenig
Curriculum Director
Wilderness Medicine Institute of NOLS

Tick-Borne Illness

2010-03-06T22:02:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

This is the next post based upon a presentation given at the Wilderness Medical Society Annual Meeting held in Snowmass, Colorado from July 24-29, 2009. The presentation was entitled “Lessons Re-learned: The US Army’s Experience with Tick –Borne Illness.” It was delivered by John Westhoff, MD, who is a Fellow of the American College of Emergency Physicians.

Dr. Westhoff made a number of great points, in a session that mentioned Rocky Mountain spotted fever, ehrlichiosis, Lyme disease, tularemia, Q fever, and southern tick-associated rash illness (STARI).

A case presentation format was used to highlight the varied way and severity in which some of these disorders can present to clinicians. For instance, a case was described in which the victim was a 49 year old with a 24 hour history of headache and chills, mildly elevated blood pressure – pulse – respirations – temperature – white blood cell count, and was initially given the diagnosis of sinusitis. One day later, the patient was seen with persistent problems, and informed of a working diagnosis of viral syndrome. Three days later, the patient had developed subjective numbness in the hands and feet, and still had a progressive low grade fever, but the white blood cell count had dropped to normal. The working diagnosis was still viral syndrome. On the fourth visit, the victim underwent a spinal tap (lumbar puncture) and was admitted to the hospital. A skin rash developed and blood testing revealed that the patient suffered from ehrlichiosis, from which there was a full recovery.

Ehrlichiosis can be severe. Dr. Westhoff described another case, in which a young man who initially presented with fever and chills and not much more deteriorated over three days sufficiently to be admitted to the hospital, and died after 8 days in the hospital, again with a diagnosis of ehrlichiosis. During his illness, he suffered from skin rash, muscle pain, high fever, infiltrates (consistent with pneumonia) in his lungs, low blood counts, and severe systemic infection with multi-organ failure. Ticks were found in his groin.

Human ehrlichiosis (there is also a canine form) is present in two forms, one caused by a rickettsial organism known as Ehrlichia chaffeensis, which is spread by Amblyomma americanum tick bites, and the other caused by the rickettsial organisms E. phagocytophila and E. equi, spread by Ixodes tick bites. Infection is usually acquired by a person who inhabits a rural environment. The average incubation period after a bite is approximately 7 to 10 days. The victims, who are more commonly middle-aged adults than children and young adults, complain of a flu-like syndrome with high fever, chills, fatigue, headache, muscle aches, vomiting, and a variety of skin rashes, which can be punctate, bumpy, like tiny bruises, or broad and reddened. A victim often has decreased counts of various types of blood cells, as well as liver dysfunction. The treatment is tetracycline 500 mg four times a day, or doxycycline 100 mg twice a day, for 10 days. The few children who have been diagnosed with ehrlichiosis have been treated with doxycycline 3 mg per kg of body weight in two divided doses per day. Untreated or treated after a delay in diagnosis, up to 15% of victims can develop severe infections, kidney failure, bleeding disorders, seizures, and/or coma.

Human anaplasmosis, which was formerly called human granulocytic ehrlichiosis, is caused by infection of white blood cells by a bacterium named Anaplasma phagocytophilum. Like ehrlichiosis, anaplasmosis is disseminated by bites of Ixodes ticks, the blacklegged tick (I. scapularis) in the Northeast and upper Midwest, and the western blacklegged tick (I. pacificus) on the West Coast. Infected persons have the onset of illness 5 to 21 days after a bite with symptoms of fever, headache, fatigue, and muscle aches, which may progress to more serious illness affecting the kidneys, central nervous system, lungs, and blood system. The treatment is the same as for ehrlichiosis.

We also learned about Rocky Mountain spotted fever (RMSF), which is most commonly seen during the months of April to September, when ticks and humans are most frequently in contact. The disease carries an incubation period of 5 to 10 days, and classically presents with fever (flu-like illness), typical rash 2 to 5 days after the fever, and a history of tick bite. Treatment is usually with doxycycline 100 mg by mouth every 12 hours (4 mg/kg/day for persons under the weight of 45 kg) for 10 days. Chloramphenicol is used for pregnant patients.

After a further discussion of features of ehrlichiosis and Lyme disease and brief discussion of tularemia, Q-fever, and STARI, the bulk of the remainder of the session was devoted to the most important topic – namely, prevention of tick-borne illnesses. The key features noted were personal skin inspection to locate and remove ticks, heightened awareness during tick season, use of appropriate insect repellents, such as DEET (33% controlled release lotion), permethrin treatment of clothing, proper wearing of clothing (long sleeves, tucked in shirts and pants), and so forth. It was emphasized that permethrin treatment of clothing is much more effective than is DEET treatment of clothing.

If you decide to apply permethrin spray to clothing, be certain to do the following:

1) Follow manufacturer’s instructions closely. Do not exceed recommended spraying times.
2) Treat clothing only. Do not apply to skin.
3) Apply the permethrin in a well-ventilated outdoor area, protected from the wind.
4) Only spray the permethrin on the outer surface of clothing and shoes.
5) In a concentration of 0.5%, it can be sprayed on both sides of clothing to lightly moisten the outer surface of the clothing item; it is not necessary to have the clothing soaked through (saturated).
6) Be certain to apply completely cover socks, trouser cuffs and shirt cuffs, where insects may attempt to crawl or fly through openings to your skin.
7) Hang treated clothing outdoors and allow to dry for at least 2 to 4 hours in non-humid conditions and for at least 4 hours in humid conditions.
8) Treat clothing no more often than every 2 weeks.
9) Launder treated clothing separately from other clothing at least once before re-treating.
10) Assume that your treated clothing is effective for repellency for 2 weeks or more. Wear it only when you need to repel insects and arthropods. Store it in a separate impermeable (to permethrin) bag when not in use.

Pain Management in Children for Broken Bones

2010-02-08T04:24:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

Pain management is a hot topic in medicine in general and certainly in medicine for the outdoors. Injuries in particular, and many illnesses, cause pain, which in turn causes the victim to suffer. To a great extent, pain is subjective, but regardless of whether your pain is a "1" or a "10," it can be disabling and even dangerous, particularly if it causes you to be distracted in a situation of risk (e.g., climbing, swimming, walking along a ridgeline).

Broken bones usually hurt a great deal. It's commonly believed that the pain is always of a severity to require the administration of "strong" pain medicine, notably, something containing a narcotic compound. This may not be true. In an article (Annals of Emergency Medicine 2009;54:553-560) entitled "A Randomized Clinical Trial of Ibuprofen Versus Acetaminophen With Codeine for Acute Pediatric Arm Fracture Pain," Amy Drendel, MD and colleagues compared the treatment of pain in children with arm fractures by using ibuprofen in a dose of 10 milligrams per kilogram (2.2 pounds) of body weight versus acetaminophen with codeine in a dose of 1 milligram per kilogram (based on the codeine component of the medication). The children were assessed for three days after discharge from an emergency department. Two hundred forty four patients were analyzed in this study.

The authors concluded that ibuprofen was at least as effective as acetaminophen with codeine for children ages 4 to 18 years with arm fractures treated as outpatients. What is also very interesting is that the children receiving ibuprofen had significantly fewer adverse effects, and both the children and their parents were more satisfied with ibuprofen. The proportion of children who had any function (play, sleep, eating, school) affected by pain was significantly lower for the ibuprofen group.

What to make of all this? The known side medication side effects measured were nausea, vomiting, drowsiness, dizziness, and constipation. Ibuprofen appears to be clearly superior in this study population. This is an eye opener for me, because I am a bit surprised (and now enlightened) by the data. I would have expected these broken bones to require more potent pain medication (e.g., a narcotic), but I see that this is not necessarily the case. In the future, I will recommend ibuprofen (if there is no contraindication) as an initial medication for many more types of pain situations, and wait to see if a more potent "rescue drug" is necessary only as needed, rather than as first choice. If remaining alert and fully functional in an outdoor setting is a priority, this makes double sense.

Proper Hydration at High Altitude

2010-02-01T02:19:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

The standard dictum when advising persons who travel to high altitude, and thus expose themselves to a lower atmospheric oxygen concentration, is to stay "well hydrated," which translates into drinking sufficient liquid that they urinate frequently, with urine color being light (not concentrated). However, this recommendation has heretofore never been based on science, just on presumption and medical common sense. So, it is with great interest that I read an article in the current issue of Wilderness & Environmental Medicine, entitled "Hydration and the Physiological Responses to Acute Normobaric Hypoxia," authored by Alan Richardson, Peter Watt and Neil Maxwell (Wilderness & Environmental Medicine 20, 212-220 (2009).

The objective of the study was to identify how hydration status, above and below normal hydration levels, affects physiological responses and onset of acute mountain sickness (AMS) symptoms during acute normobaric (normal atmospheric pressure - equivalent to that at sea level) hypoxia (lowered concentration of oxygen in the air). In this study, eight males subjects completed intermittent walking tests in the condition noted after controlled normal hydration (euhydration), hyperhydration (too much water) and hypohydration (dehydration - too little water) protocols. During the measurement period of approximately 2 hours' exposure, heart rate, core body temperature, peripheral arterial blood oxygen saturation, urine osmolality (a measure of concentration and thus the state of hydration), and self-reported AMS scores were obtained.

The observations and analysis showed that the different states of hydration had a significant effect on all of these parameters, and that hydration state above (hyper-) and below (hypo-) normal hydration had detrimental consequences on physiological strain and onset of acute mountain sickness symptoms under the conditions studied.

This is very important work, and will undoubtedly spur further investigation. We are fairly familiar with the concept of hypohydration, which leads to dehydration and all of its deleterious effects upon performance and body functions. However, in the setting of high altitude, we are less familiar with hyperhydration (too much water), because we don't encounter it very often, unless it is induced by a doctor- or rescuer-led intervention. We suspect that fluid retention in general, when it occurs for whatever reason, may contribute to the accumulation of fluid in the brain (AMS) or perhaps even the lungs (high altitude pulmonary edema), but this has never been proven. The worsening of headache in this study (as a presumptive symptom of AMS and perhaps harbinger of fluid accumulation in the brain) in the hyperhydration group is a bold word of caution to us to attempt to achieve normal hydration, and nothing more, with our fluid replacement strategies. How best to do this? At the current time, the best we have in the field is maintaining urine color, specific gravity and/or osmolality (signs of urine concentration and thus state of hydration) at preferred values. However, with the advent of technologies such as that offered by Cantimer, we may soon have other methods by which to guide fluid administration, as thirst in and of itself is notoriously not sufficiently precise for this purpose.

SAM Splint versus Philadelphia Collar

2010-01-25T01:41:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

In an issue of Wilderness and Environmental Medicine (Volume 20, Number 2, 2009), Todd McGrath and Crystal Murphy have written an article entitled “Comparison of a SAM Splint-Molded Cervical Collar with a Philadelphia Collar.” The objective of this study was to compare the effectiveness of a SAM Splint molded into a cervical collar with that of a Philadelphia collar (commonly used by paramedics and others to hold a neck motionless during transport after an accident) at limiting movement of the cervical spine (neck) in a variety of common predicted directions of motion.

Healthy volunteers participated in the study. A goniometer was used to measure degrees of maximal extension (bending the neck backwards) and lateral motion (left and right) with each type of collar. After data analysis, it was concluded that the results of this study suggest that the SAM Splint, when molded into a cervical collar, is as effective as the Philadelphia collar at limiting movement of the cervical spine.

This is good news for rescuers, backpackers, athletic medical responders and others who have occasion to splint an injured or potentially injured neck in the field. I have used SAM Splints to fashion cervical collars for many years, because my observations were that it could be quickly configured into a reliable and functional splint for this purpose, so it is nice to have my suspicions confirmed. There is certainly nothing wrong with using a (preferably, lightweight) Philadelphia collar or other similar pre-molded appliance to maintain a neck motionless when necessary. The general considerations will be space, weight, ease of use, and adaptability to a variety of patient sizes and conditions. Furthermore, it cannot be overemphasized that if you wish to use a SAM Splint or any other rescue product in the outdoors for which operator skill and experience are required, you should take the time to practice beforehand in a controlled and non-frenetic environment.

Frozen Autoinjectors and Armpits

2010-01-17T22:05:00Z

I recently exchanged emails with a fellow who asked if it was acceptable to freeze the auto-injector in his first aid kit. I told him of course not, you may not have time to thaw the medication. Now curious, I intentionally froze four expired EpiPens® on a minus 22ºF night and timed how long it took to thaw the auto-injectors in my armpit.

The first one mechanically fired with a normal amount of pressure while frozen, the needle extended, but no liquid was ejected. When opened the epinephrine was frozen and there were no obvious cracks in the tubex. I then thawed the remaining three EpiPens® in my left armpit (97ºF via our household mercury thermometer).

At 3 minutes I discharged the second EpiPen®, but only a little bit dribbled out of the needle. I opened this EpiPen® and found the epinephrine still frozen.

At 4 minutes I discharged the third EpiPen® and I saw a stream of liquid, but it seemed less than expected. The epinephrine in this unit was partially thawed.

At 5 minutes I discharged the last EpiPen® and observed a decent steam of liquid and upon opening, found the remaining epinephrine liquid.

Likewise I froze an ampule of epinephrine. This was thawed after 3 minutes under my armpit. The ampule was not cracked. Several years ago we did the same test on one of the older “AnaGuard” syringes and it took 5 minutes to thaw completely.

So there you have it, backyard science to support the common sense practice of keeping a liquid emergency medication thawed and ready to use. It makes no sense to tempt fate and hope you can thaw your medication in time. Keep it close to your body in cold weather.

There is a second question here, will frozen and thawed epinephrine work? If it was frozen and thawed, and I needed it, and it was not discolored with precipitates floating around, I'd use it. According to the UIAA Medical Commission, yes, it will be biologically active. However, freeze-thaw is not the best situation and will accelerate the deterioration of the medication. It can also crack the ampule or syringe and affect sterility of the product.

Take care

Tod

Kupper, Th. Milledge, J. Basnyat, B. Hillebrandt, D. Schoffl, V The Effect of Extremes of Temperature on Drugs. Consensus Statement of the UIAA Medical Commission Vol 10 2008