Wilderness Medicine

Immersion Foot

2008-05-15T22:38:00Z

The view from my window is of the eastern slope of the Wind River Range. The high country gleams white with snow. The lower slopes are green with spring, or white with snow, depending on the day, or sometimes the hour. My hike last weekend was a combination of snowshoeing in wet snow and slopping through mud, conditions ripe for a non-freezing cold injury such as immersion foot.

Most people don’t know this injury, because like I did last weekend, they go home at night. It’s the multi-day hikers, the soldiers and others who stay outdoors in wet and cold who are at risk.

In immersion foot, like frostbite, blood vessels constrict in response to cold and damp. In this case it’s cold enough to impair circulation, but not to freeze tissue. Cells are deprived of oxygen and nutrients.   Nerves are especially sensitive, which accounts for the numbness, pins and needles sensations, itching and pain that often announce the injury.

In the field it’s common to see cool pale extremities, numbness or tingling, itching and mild swelling. It’s less common to see the textbook appearance of cold, swollen, numb, cyanotic and mottled skin, or the warm, swollen, red and painful skin that surprises the camper after they take their first warm shower.

There isn’t much we can do to treat this in the field. We need to recognize it, keep the foot dry and warm and go see the doctor. The pain can be awful and difficult to manage with medications. Severe cases result in tissue loss. Moderate cases can be painful and sensitive for weeks, months and even years.

We used to think sleeping with warm dry feet prevented injury, no matter how cold they were during the day.   This is probably true in many cases, but I’ve seen immersion foot develop over a day and in a cold multi-hour river crossing. There must be individual susceptibility issues. As well, this day may be the tipping point after several days of exposure. An afternoon of lapsed attention that unravels days of diligent prevention.

Footwear isn’t a panacea, although today’s plastic boots are a godsend compared to the leather we used to wear.   You can get a non-freezing cold injury from sweat-dampened socks, neoprene socks and other vapor barrier systems, as well as with supergaitors and snowpack boots. It happens to novices and experts, in summer and winter, in the deserts and mountains, and even in the jungle. It’s a consequence of how cool and damp your extremities are, no matter what you wear on your feet.

The adage that “cold injuries are a leadership challenge long before they are a medical problem” is certainly true. Prevention starts by looking at your feet, and the feet of those you lead. Don’t assume.   This injury surprises people.

The prevention toolbox is deep with advice: wool or synthetic socks; keeping the body warm; massaging the feet twice a day; sleeping with dry and warm feet; drying wet socks against your skin; warming you feet during the day; keeping your feet out of water or mud as much as possible; watching carefully and reacting promptly if you experience numbness or tingling; keeping footwear loose to allow for circulation.

I’ve tried vapor barrier, and anti-perspirants for my sweaty feet, with mixed success. I’m partial to changing my socks in the middle of the day, which makes me look at my feet. They surprised me once years ago. I’m sure they can do it again. I don’t tolerate numb toes, and my threshold for dealing with cold toes is low. Changing my socks gives my students permission to do the same and shows that cold, damp socks is not a sign of toughness, rather, it’s a bad habit.

Take care

Tod

Sea Bather’s Rash

2008-05-05T01:09:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

From the month of May through September, oceangoers along the U.S. Gulf coast need to be concerned about a particular form of skin rash caused by tiny jellyfish. As the summer season progresses, this can also become a problem along the entire eastern seaboard. I've been afflicted while scuba diving in Cozumel, Mexico, and the episodes can be much more than a minor annoyance. Indeed, the intensity with which some people react to these particular stings was an impetus for the development of Safe Sea, a jellyfish sting inhibitor product for which I participated in the design of clinical trials.

Sea bather’s eruption, often misnamed "sea lice" (which are true crustacean parasites upon fish), occurs in seawater and more often involves bathing-suit-covered areas of the skin, rather than exposed areas. The skin rash distribution is very similar to that from seaweed dermatitis, but no seaweed is found on the skin. The cause is stings from the nematocysts (stinging cells) of thimble jellyfish, such as Linuche unguiculata, and the larval forms of certain anemones. The victim may notice a tingling sensation under the bathing suit (breasts, groin, cuffs of wet suits) while still in the water, which is made much worse if he takes a freshwater rinse (shower) while still wearing the suit. The rash usually consists of red bumps, which may become dense and confluent. Itching is severe and may become painful.

Treatment is often not optimal, because application of vinegar or rubbing alcohol to stop the envenomation may not be very effective. An agent that may work better is a solution of papain (such as unseasoned meat tenderizer), which may be applied using a mildly abrasive pad, although a good outcome is not guaranteed. After the decontamination with any agent and a thorough freshwater rinse, apply hydrocortisone lotion 1% twice a day to treat the inflammatory component of the skin reaction. If the reaction is severe, the victim may suffer from headache, fever, chills, weakness, vomiting, itchy eyes, and burning on urination, and should be treated with oral prednisone as if he suffered from poison oak. Topical calamine lotion with 1% menthol may be soothing.

Prevention is obviously quite important. If you are able to obtain the product, cover exposed skin areas with Safe Sea. This includes at least a few inches underneath the cuffs of wet suits or Lycra-type "stinger suits" that are equipped with elastic cuffs at the wrists and ankles, and sometimes around the neck. If you only wear a normal bathing suit, which does not have tight cuffs, the tiny creatures can easily wash onto your skin underneath the suit, where they can wreak havoc. So, if you are concerned about the possibility of seabather's eruption, you must also apply the Safe Sea underneath your bathing suit. If there are "thimbles" (jellyfish) visible in the water, it is best to stay out. If you are swimming in apparently uninfested water and begin to feel a tingling sensation on your skin, then the "swarm" may be moving into your location and you should exit the ocean.

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

Hands-Only CPR

2008-04-01T20:47:00Z

I imagine you have heard of or seen the media splash today on “Hands-only” CPR.   It’s not an April’s Fools Joke.   It stems from a press release by the American Heart Association (AHA) yesterday (Mar 31) that in turn reflects the position of their Emergency Cardiovascular Care (ECC) Committee.   You can read the complete scientific article on this in Circulation at http://circ.ahajournals.org.

While this shocks some folks like a runaway defibrillator, if you follow the research trends on CPR it’s not a surprise. The science for some time has questioned the value of rescue breathing (mouth to mouth/mask) for people who don’t suffer cardiac arrest secondary to hypoxia. In 2005, the AHA almost took this step, but instead wrote “Laypersons should be encouraged to do compression-only CPR if they are unable or unwilling to provide rescue breaths, although the best method of CPR is still compressions coordinated with ventilations.”   In addition, the AHA Guidelines have recommended compression only CPR for dispatcher-assisted instructions for untrained bystanders.

This new change was supported by evidence published from several recent large studies, which looked at hundreds of incidents of bystander CPR on cardiac arrest victims. None of the studies demonstrated a negative impact on survival when ventilations were omitted from the bystanders’ actions.

The AHA states that Hands-Only CPR should not be used for infants or children (who tend to have cardiac arrests secondary to hypoxia), for adults whose cardiac arrest is from respiratory causes (like drug overdose or drowning), or for an un-witnessed cardiac arrest (where ventilations may benefit the victim who has not been breathing for several minutes).

Hands-only CPR is designed for a witnessed collapse on an adult when there is immediate access to an EMS system. The two key points in the training are 1) Call 911 and 2) start compressions (hard, fast, uninterrupted).

The AHA ECC committee isn’t recommending abandoning ventilations and compressions. They ideally want people prepared to manage all types of cardiac arrests.   The recommendation and press release is accompanied by a “Call to Action”.   The AHA is addressing the low rate of bystander CPR, which may be due to fear of disease from rescue breathing and fear of performing CPR incorrectly.

WMI doesn’t plan to change our CPR curriculum. We will describe this technique and it's rationale for our students. Hypoxia is a possible cause of cardiac arrests in the wilderness (drowning, avalanche burial). As well, wilderness CPR does not have access to 911 and AED’s, and rescue breathing is an important adjunct to chest compressions.   For our context, ventilation and compressions are an important skill.

Tick Attachment Sites

2008-03-31T01:10:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

The first issue of Volume 19 of the journal Wilderness & Environmental Medicine has just been published. It contains some very interesting information, some of which I will share with you in this and another post.

In an article entitled "Tick Attachment Sites," Abdulkadir Gunduz and his colleagues looked at the location of attached ticks in 67 patients who presented to their emergency department with a history of tick bites. They noted that 20% of the ticks were attached to regions of the body that patients could not themselves visualize. Since it is important to remove attached ticks before they become embedded, and as soon as possible to minimize the transfer of infectious agents or toxic (salivary) fluids, this highlights the need for a full body inspection of any person who has recently traveled in endemic (for ticks) country.

In Turkey, there is concern for transmission of fatal cases of Crimean-Congo hemorrhagic fever from the tick genus Hyalomma, while in the U.S., we are more familiar with the genera Amblyoma, Dermacentor, and Ixodes, and the disorders of Lyme disease, Rocky Mountain spotted fever, ehrlichiosis, and tick paralysis.

In this particular study, the most common tick attachment sites were the lower limbs, followed by the lower abdomen and genital region, then the back (at the level of the chest), and the buttocks. Given that most people would not be able to spot a tick, which may be very tiny if in a juvenile form, in some of these (and other) locations, it is prudent if traveling through tick country to have someone you trust perform a "tick check," or use a mirror if one is available. If a tick appears to be attached and cannot be removed by the human host in its entirely, then he or she should get assistance for its removal.

photo of tick courtesy of www.lymediseaseaction.org.uk

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

Wilderness Medical Society 25th Annual Conference

2008-03-25T19:23:00Z

The 25th Anniversary and Annual Meeting of the Wilderness Medical Society will be held in Snowmass, Colorado, July 26-30, 2008. You can learn more about the meeting and register at www.wms.org/.

The meeting has 49.5 continuing medical education (CME) and 46.25 Fellowship of the Academy of Wilderness Medicine (FAWM) credit hours for participants through lectures, skills instruction and 49 different workshops. The conference committee has brought together many of the finest presenters from years past for this special anniversary. While this is a physician oriented society you’ll find the Wilderness Medical Society very welcoming to non-physicians, especially those of us who practice wilderness medicine as part of our profession of outdoor and wilderness education.

We've come a long way from the days of first aid courses with wilderness advice from our friendly local climbing doctor. We have curriculum such as WFA and WFR that many organizations have decided are the most relevant for their outdoor program leaders. We have research, textbooks, journals and a professional Academy to recognize those with extensive study in this speciality. We have evidence to guide what we need to know. We've discarded practices we learn are ineffective, and focus on what we believe is relevant and practical for the context in which we practice. A 25th annual meeting is testimony to the development of this legitimate medical specialty of wilderness medicine.

Picaridin-Based Insect Repellent

2008-03-23T17:38:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

There is a plethora of insect repellents on the market. Many of the newer repellents are intended to replace DEET (N,N diethyl-m-toluamide), which is an excellent and reliable repellent, but which carries a distinctive odor, can dissolve certain fabrics, and has been associated with rare reports of toxicity when used in high concentrations. Newer insect repellent choices include picaridin, which is advertised to be odorless, nontoxic, and non-injurious to clothing and tents. Wanting to give it a try, I carried a bottle of Cutter Advanced Insect Repellent (With Picaridin!) on a fishing trip this past summer to British Columbia. The main component in this product is picaridin 7%.

In previous years, I have relied upon DEET, namely, DEET PLUS Composite Insect Repellent Lotion from Sawyer Products, which contains as its main component 17.5% DEET, and which has always been very effective. I have been using this product for years, because I continue to replenish my first aid kid from a supply I obtained nearly a decade ago. Despite this period of time, the repellent continues to perform very well and with no apparent decrease in its effectiveness.

The Cutter Advanced Insect Repellent with picaridin was easy to apply and, as advertised, was colorless and odorless. However, in my subjective, one-person observation, it wasn't as effective against the mosquitoes at our camp as was DEET. I took care to carefully apply the picaridin-containing spray to the exposed skin on my forearms, hands, face, neck, and legs, but found that I continued to be bitten by mosquitoes. The spray worked to a certain degree, as I did receive as many bites as I suffered without using the spray, but on many occasions, I needed to add the DEET Plus lotion in order to keep the mosquitoes off my skin. Furthermore, when I used DEET Plus alone instead of the picaridin spray, the former seemed to be much more effective.

Does this mean that there is no role for picaridin? Not at all. It certainly lessened the number of mosquito bites, and it is true that it is easy to apply and sports the physical characteristics as advertised. However, I have heard from a few others that their experience with picaridin has been the same, namely, that it seems to be less effective when the mosquitoes are plentiful and/or voracious, and that if an application is not perfect (e.g., a patch of skin is not treated), the mosquitoes are not repelled by picaridin in the vicinity (e.g., on treated skin) to the same degree that they might be if DEET had been used.

My recommendation at this time is that picaridin has a place as a mosquito repellent, but the user should be aware that if there is a serious concern about mosquito bites (e.g., with transmission of disease, such as West Nile virus or malaria), one should still be utilizing a DEET-containing product, use mosquito netting, pre-treat clothing with permethrin, and so forth.

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

Avalanche Injuries

2008-02-22T05:14:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

It was recently reported that a man buried by an avalanche for nearly 8 hours survived after being found with an avalanche probe. According to the victim, he was buried face up 4 feet below the surface of the snow. If he survived, there is no other conclusion to draw other than that he had sufficient air to breathe and was able to tolerate a drop in his core body temperature.

As noted by Knox Williams and his co-authors in the dealing with avalanches in the forthcoming 5th edition of the textbook Wilderness Medicine, avalanche deaths have increased in the U.S. each decade since 1950. From 1950 to 2004, 716 people died in avalanches. The average age of all victims was 30 years. The youngest was 6 years; the oldest, 67 years.

The man described in the first paragraph above was snowmobiling when he was caught in the snow slide. Most victims are pursuing some form of recreation at the time of their accident, with climbers, backcountry skiers, and snowmobilers heading the list. Miscellaneous recreation includes sledders and persons playing in the snow, campers, and even an unlucky ski kayaker. Among non-recreation groups, avalanches strike houses (residents), highways (motorists and plow drivers), and the workplace (ski patrollers and others whose jobs put them at risk).

Some of the factors that influence a buried victim’s chances for survival are time buried, depth buried, clues on the surface (to facilitate location of the victim and rescue), rescue equipment, injury, ability to fight the avalanche, body position, snow density, presence of air (breathing) pocket and size of air pocket, and luck. A victim who is uninjured and able to fight on the downhill ride usually has a better chance of ending up only partly buried, or if completely buried, a better chance of creating an air pocket for breathing. A victim who is severely injured or knocked unconscious is like a rag doll being rolled, flipped, and twisted. Being trapped in an avalanche is a life-and-death struggle, with the upper hand going to those who fight the hardest.

Avalanches kill in two ways. First, serious injury is always possible in a tumble down an avalanche path. Trees, rocks, cliffs, and the wrenching action of snow in motion can do horrible things to the human body. Second, snow burial causes asphyxiation (either obstructed airway or exhausted oxygen supply). A very small percentage of avalanche victims succumb to hypothermia, probably because they succumb to injuries or asphyxia before they have a chance to become sufficiently hypothermic to expire.

The problem of breathing in an avalanche does not start with being buried. A victim swept down in the churning snow has an extraordinarily hard time breathing. Inhaled snow clogs the mouth and nose; asphyxiation occurs quickly if the victim is buried with the airway already blocked. Snow that was light and airy when a skier carved turns in it becomes viselike in its new form.

Snow sets up hard and solid after an avalanche. It is almost impossible for victims to dig themselves out, even if buried less than a foot deep. Hard debris makes recovery very difficult in the absence of a sturdy shovel. The pressure of the snow in a burial of several feet sometimes is so great that the victim is unable to expand his or her chest to draw a breath. Warm exhaled breath freezes on the snow around the face, eventually forming an ice lens that cuts off all airflow.

Another factor that affects survival is the position of the victim’s head; that is, whether they were buried face up or face down. The most favorable position is face up. Data from a limited number of burials show the victim is twice as likely to survive if buried face up rather than face down. If buried face up, an air pocket forms around the face as the back of the head melts into the snow; if buried face down, an air pocket cannot form as the face melts into the snow.

A completely buried victim has a poor chance of survival. Survival is interrelated with both time and depth of burial. Survival probabilities diminish with increasing burial depth. To date, no one in the U.S. who has been buried deeper than 2.1 m (7 feet) has been recovered alive.

Time is the true enemy of the buried victim. In the first 15 minutes, more persons are found alive than dead. At 30 minutes, an equal number are found dead and alive. After 30 minutes, more are found dead than alive and the survival rate continues to diminish. In favorable circumstances, buried victims can live for several hours beneath the snow; therefore rescuers should never abandon a search prematurely. In 2003, two snowshoers caught near Washington’s Mt. Baker survived burials of 22 and 24 hours. Such long survival times are a reminder that no rescue should be abandoned prematurely on the thought that the victim is dead.

The Value of Wilderness Medicine Research

2008-02-07T23:23:00Z

Last week WMI held it’s annual staff meeting in Lander, Wyoming. One of our guest speakers, Stuart Harris MD, is the Director of the Wilderness Medicine Fellowship at Harvard and a high altitude researcher. He talked about hypoxia as a fundamental problem in medicine and how altitude illness allows us to focus on hypoxia in generally healthy subjects, and gain insights that would be obscured in patients with chronic lung and heart disease.

This brought to mind thoughts on the value of wilderness medicine research in the face of the massive health problems of heart disease, cancer, diabetes, malaria and diarrhea in the third world. Does this work benefit only a small group of healthy and wealthy people able to recreate in the wild, or does it have broader implications?

Researching venoms seems silly, especially in North America where snake envenomations are really at the bottom of the lists of things that kill us. Yet researchers studying the incredibly toxic venom of the stonefish have learned of proteins in the venom which open up pores in the cell walls, allowing the toxic venom component to enter the cell. This has sparked investigation into whether we can piggyback therapeutic medicines onto these proteins, and, using chemotherapy as an example, achieve the desired effect with less medicine, and less side effects.

A new diabetes drug is a synthetic version of a peptide found in the saliva of the Gila monster, a poisonous lizard that lives in the Southwest and Mexico. Hypothermia is applied therapeutically to survivors of cardiac arrest, and cooling systems for athletes may prove useful treatments in urban heat waves.

Wilderness medicine research also highlights conservation. The loss of forests and coral reefs reduces a source of medications. Compounds from the oceans are now being tested as treatments for chronic pain, asthma and various malignancies, including *** cancer. Medicinal botany has produced more than 100 important drugs, including aspirin (willow bark), digitalis (from foxglove), morphine (opium poppies) and the anti-malarial drug quinine (the bark of the cinchona tree).

There are many other examples, from work on pulmonary artery hypertension, a component of high altitude pulmonary edema, to reperfusion injuries, a component of frostbite, of the link between the application of science from wilderness research to non-wilderness health care. If you’re interested in more on this subject, look into Dr. Charles Houston’s ‘Going Higher’. It has an excellent and readable chapter on what we can learn about important healthcare issues in the non-wilderness world by studying hypoxia and altitude illness.

Take care

Tod

Treatment for Burns

2008-02-03T23:15:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

1. Remove the victim from the source of the burn. If his clothing is on fire, roll him on the ground or smother him in a blanket to extinguish the flames. If the victim has been burned with chemicals, gallons of water should be used to wash off the harmful agents. If the eyes are involved, they should be irrigated copiously. Phosphorus ignites upon contact with air, so any phosphorus in contact with the skin must be kept covered with water. Do not attempt to neutralize acid burns with alkaline solutions or vice versa; the resultant chemical reaction may liberate heat and worsen the injury. Stick to irrigation with water. If clothing remains stuck to the skin and does not fall away with irrigation, do not tear the clothing away. Cut around it.

2. Evaluate the airway. Look for evidence of an inhalation injury: burns of the face and mouth, singed nasal hairs, soot in the mouth, swollen tongue, drooling and difficulty in swallowing saliva, muffled voice, coarse or difficult breathing, coughing, and wheezing. If it appears that an inhalation injury has occurred, administer oxygen by face mask at a flow rate of 5 to 10 liters per minute, and transport the victim to a hospital as quickly as possible.

3. Examine the victim for other injuries. Unless the airway is involved or the victim is horribly burned, the burn injury will not be immediately life threatening. In your eagerness to treat the burn, don’t overlook a serious injury such as a broken neck. Control all bleeding and attend to broken bones before applying burn dressings.

4. Treat the burn:

First-degree: A first degree burn, such as a mild to moderate sunburn, may be treated with cool, wet compresses. If the burn is acquired suddenly (as when a child grabs a hot rock), immediate application of very cold water (not solid ice) may help limit the extent of the tissue damage. Oral administration of an anti-inflammatory drug, such as aspirin or ibuprofen, may provide considerable relief. For severe sunburn (“lobster body”), the administration of oral prednisone in a rapid taper (80 mg the first day, 60 mg the second, 40 mg the third, 20 mg the fourth, 10 mg the fifth) may be extremely helpful. Corticosteroids should always be taken with the understanding that a rare side effect is serious deterioration of the head (“ball” of the ball-and-socket joint) of the femur, the long bone of the thigh.

Topical corticosteroid creams or ointments are of no benefit in treating a burn wound. Anesthetic sprays that contain benzocaine work for a few hours, but may induce allergic reactions. They should be used sparingly. If no blisters are present, a moisturizing cream (such as Vaseline Intensive Care) will help soothe the skin. Aloe vera gel or lotion seems to promote resolution of extensive first-degree burns. Burnaid first-aid burn gel (Rye Pharmaceuticals), which also comes in an impregnated dressing, contains 2 to 4% melaleuca oil and is advertised to provide relief from the pain of minor burns and scalds.

Second-degree: A second-degree burn should be irrigated gently to remove all loose dirt and skin. This should be done with the cleanest cool water available. Never apply ice directly to a burn; this may cause more extensive tissue damage. Cool compresses may be used for pain relief.

After the wound is clean and dry, cover it with a soft, bulky dressing made of gauze or cloth bandages, taking care to keep the dressing snug but not tight. If antiseptic cream such as silver sulfadiazine (Silvadene) is available, it should be applied under the dressing. An alternative is mupirocin ointment or cream, or bacitracin ointment. A nonadherent dressing layer directly over the antiseptic is easier to change than coarse gauze. Another excellent covering is Spenco 2nd Skin underneath an absorbent sterile dressing. Spenco 2nd Skin is an inert hydrogel composed of water and polyethylene oxide. It absorbs fluids (so long as it doesn’t dry out), which “wicks” serum and secretions away from the wound and promotes wound healing. Other occlusive hydrogel-type dressings are NU-GEL (preserved polyvinyl pyrrolidone in water) and Hydrogel, which can absorb up to 21/2 times its weight in exuded (from the wound) fluids. Yet another covering for a burn is a layer of petrolatum-impregnated Aquaphor gauze under a dry (absorbent) gauze dressing.

Do not apply butter, lanolin, vitamin E cream, or any steroid preparation to a burn. These can all inhibit wound healing, and may facilitate infections with increased scarring.

Dressings should be changed each day to readjust for swelling and to check for signs of infection. Be certain to keep burned arms and legs elevated as best possible, to minimize swelling and pain.

Blisters should not be opened, unless they are obviously infected and contain pus (this will generally not occur until 24 to 48 hours after the burn injury). If a blister remains filled with clear fluid, it is an excellent covering for the wound and will minimize fluid loss and infection. There is no rush to remove charred skin from a burn wound. As the wound matures and dressings are changed, gentle scrubbing will lift off dead tissue.

A victim with large areas of second-degree burns may need to be treated for shock.

Third-degree: A third-degree burn should be irrigated gently and covered with antiseptic cream or ointment or Spenco 2nd Skin, and a dry sterile dressing.

If a first-degree burn involves more than 20% of the body surface area and the victim suffers from fever, chills, or vomiting, a physician evaluation is required. If a second-degree burn involves a significant portion of the face, eyes, hands, feet, genitals, or an area greater than 5% of the total body surface area, a physician evaluation is required. Body surface area can be estimated using the “rule of nines.” For an adult, each upper limb equals 9% of total body surface area (TBSA), each lower limb equals 18%, the anterior and posterior trunk equal 18% each, the head and neck combined equal 9%, and the genital/groin area (perineum) equals 1%. For a small child, each upper limb equals 9% of TBSA, each lower limb equals 14%, the anterior and posterior trunk equal 18% each, the head and neck combined equal 18%, and the perineum equals 1%. Another method to estimate involved body surface area is the “palm of hand” rule: The surface area of the victim’s palm without the fingers represents approximately 1 to 1.5% of his TBSA. All third-degree burns are serious and should be seen by a physician.

Wet versus Dry Dressings

If the burn surface area is small (less than 10% of total body surface area), then cool, moist dressings (not ice) may be used to initially cover the burn wound. These often provide greater pain relief than do dry dressings. If the surface area involved is large, however, dry, nonadherent dressings should be used, in order to avoid overcooling the victim and introducing hypothermia. Because the skin is the major thermoregulatory organ of the body, it is difficult for an extensively burned victim to control his body temperature, so great care must be taken when wetting down such a person. If the victim begins to shiver, the cooling is too extreme.

General First-Aid Principles

2008-01-17T04:44:00Z

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

The following is adapted from Medicine for the Outdoors:

In all first-aid situations, the rescuer must remain calm. If you panic, you may lose control of the victim, as well as of yourself. To establish authority, speak and act calmly and purposefully. Allow the victim to discuss the incident, his (or her) situation, and his fears. If you can involve the victim in his rescue and treatment, it is often good for morale. Try not to be judgmental and save criticism for after the event. Avoid laying any blame on people; they may get hurt emotionally or become argumentative as a result. When communicating with a victim and bystanders, remember that you are not only caring for the victim, but in many ways, for family and friends. It is important to communicate frequently, honestly, and in a manner that is reassuring and inspires cooperation and hope.

1. Do not endanger additional inexperienced rescuers. If you cannot get to the victim easily, send for help. Approach all victims safely; don’t allow the sense of urgency to transform a sensible rescue into a series of risky, or even foolhardy, maneuvers. If it appears that the victim is too ill to be moved, set up camp and create a shelter immediately. In all cases, protect the victim from the elements from above and below.

2. If you have paper and a writing instrument, record your observations. If you send someone for help, have him carry a piece of paper that states the victim or victims’ location, the nature of the emergency, the number of people needing help, the condition of the victim(s), what is being done to treat the victim(s), and any specific environmental conditions or physical obstacles. Accident report forms are available from organizations such as The Mountaineers.

3. Always assume the worst. Assume that each victim you encounter has a broken neck or a heart attack until proven otherwise. Always be conservative in your treatments and recommendations for further evaluation or rescue.

4. Never move a seriously injured victim unless he is in danger from the environment or needs to be moved for medical reasons. Don’t encourage a victim to get up and “shake it off” until you have examined him as fully as possible for a potentially serious problem. If you must remain in a wilderness location for a prolonged period of time caring for a victim, remember to attend to the basic survival requirements, which include air (oxygen) for breathing, shelter, water, food, psychological support, and human waste disposal.

5. Don't administer medicines or perform procedures if you are not sure what you are doing. The good Samaritan has certain legal protections for his actions so long as he operates within prudent limits and takes reasonable care. A good rule to follow is primum non nocere: “First of all, do no harm.” If you are not certain what to do and the situation isn’t worsening, don’t interfere. Explain to the victim that you are not a physician, but will do your best to get him through whatever crisis he has encountered, to the best of your knowledge and ability. If you encounter a victim who may be seriously ill, seek an expert opinion as soon as possible. Even if your treatment seems successful, it is wise to consult a physician if you would have ordinarily done so.

6. Listen carefully to the patient. The story of what happened and the medical history can be extremely important in making swift and appropriate medical decisions. Let the victim tell you what happened in his or her own words, and try not to interrupt unless it is important. If a victim has a sprained ankle, a comprehensive discussion may not be necessary, but if it is appropriate, try to elicit the following:

Current illness: What happened? When did it happen? Why did it happen? If the victim is suffering pain, describe its location, time of onset, whether it came on suddenly or gradually, whether it comes and goes, its quality (dull, sharp, cramping, etc.), how it is made worse or relieved, and whether the victim has suffered anything similar before (and if so, whether there was a medical diagnosis). Have the victim describe all symptoms, such as nausea, vomiting, diarrhea, blurred vision, shortness of breath, fatigue, cough, etc.

Prior illnesses and preexisting conditions: Have the victim describe any previous illness (heart attack, asthma, pneumonia, meningitis, etc.) and any current conditions (diabetes, anemia, abnormal heart rhythms, etc.) and how they have been and are currently being treated.

Surgeries: Have the victim list any surgical operations, such as appendectomy or knee surgery.

Allergies: This includes allergies to food, plants, insects, and medication(s) and the nature of the allergic reaction(s).

Immunizations, exposure to communicable diseases, foreign travel, recent dietary history: Any of these may be appropriate if the victim is perhaps suffering from an infectious disease, including food poisoning or toxic ingestion.

Review of systems: This is a comprehensive questioning of each organ system to determine if the victim has or has ever had symptoms referable to each system:

Head: headache, dizziness
Eyes: blurred vision, double vision, decreased vision, discharge, pain
Ears: decreased hearing, ringing in the ears, discharge from the ears, pain
Nose: nosebleeds, difficulty breathing, nasal discharge, sinus infection
Throat: sore throat, foreign body sensation, tonsillitis, hoarseness or difficulty talking, painful swallowing, difficulty swallowing
Dental: tooth loss, abscess, dentures
Neck: pain, decreased range of motion, arthritis
General: fever, chills, weakness, unintentional weight loss or gain, dizziness, history of intravenous drug use
Chest(lungs): difficulty breathing, shortness of breath, wheezing, cough (productive of sputum or nonproductive), coughing blood, history of tobacco use
Heart: palpitations, chest pressure-like sensation, chest pain
Abdomen: pain, mass
Gastrointestinal: nausea, vomiting (describe what is vomited), diarrhea (describe consistency), red blood in stools or dark black stools, yellow skin (jaundice), perianal itching, constipation, excessive gas, bloating, belching
Hematologic/immune: anemia, frequent infections, exposure to HIV
Genitourinary: change in frequency of voiding, painful urination, discolored or malodorous urine, back pain, blood in urine, history of sexual contacts, penile or vaginal discharge, date and character of last menstrual period (normal, abnormal), vaginal bleeding
Neurologic: seizure, weakness in any body part, numbness or tingling of any body part, difficulty with coordination or walking, difficulty with speech or comprehension, fainting
Muscular: muscle cramps, weakness, incoordination, pain
Psychiatric: abnormal thinking, hallucinations (visual or auditory), desire to hurt self or others, inappropriate crying or laughing, depression

Reprinted with permission

Medical Decision-Making

2008-01-10T23:08:00Z

As an ambulance EMT I make an assessment, provide necessary treatment, and in most cases transport the patient. I rarely make a decision whether or not the patient needs to see the doctor.

Yet in the wilderness this may be my decision to make. My judgment can affect the patient’s health, the safety of my expedition members, and the quality and success of our planned journey or climb. This is an understated difference between urban and wilderness medicine, especially for those of us whose experience and expertise lies in outdoor practices, not practicing medicine. We may be well trained as WFR’s or WEMT’s, but our actual patient care experience is often limited. The decisions we may have to make can range from the critical (whether to evacuate someone with a belly ache), to the commonplace (whether to bandage a blister).

Pre-hospital medical courses rarely have a component addressing how decisions are made, or the elusive, yet critical asset of good “clinical judgment”. I find it a fascinating area of study and have gathered some thoughts in an article on medical decision making that you can access at www.nols.edu/wmi/curriculum_updates/.

If you’re interested in this topic, you will find “How Doctors Think” by Jerome Groopman M.D. (Houghton Mifflin, 2007) a very readable presentation of how medical decisions are made. In contrast to the seductive power of intuition made popular by Malcolm Gladwell’s “Blink”, Groopman presents a contrasting view with old fashioned virtues of careful, deliberate and systematic thinking – a decision-making process that can serve us well when we use our judgment in the wilderness.

Take care

Tod

NOLS Incident Database Paper Published

2007-12-19T20:42:00Z

A new paper based on the National Outdoor Leadership School's Incident database has been published in the Journal of Wilderness and Environmental Medicine (18, 298-304(2007). It gives a perspective on injury and illness rates at NOLS from 2002-2005. You can access it at: http://www.nols.edu/resources/research/abstracts.shtml. The title is Medical Incidents and Evacuations on Wilderness Expeditions.

In 1984 NOLS created a comprehensive safety database to record incident data; all injuries, illnesses, near-miss incidents, and evacuations that occur on courses. At 23 years and counting we believe it’s the longest running dataset in the industry, with more than 3 million person days of experience and 13,000 records. These data are used to guide the development of WMI’s curriculum and the wilderness medicine and risk management practices of NOLS. This is the latest of three peer reviewed journal papers generated from this database.

A Dislocation Tale

2007-12-13T03:29:00Z

One of the illusions about wilderness medicine is that we teach our students techniques which are beyond our skill or experience, that really are the province of a physician.    Some of the blame for this miss-perception lies in wilderness medicine instructors, who in their enthusiasm, distort the differences between first aid in the city, and in the wild.

In reality, most of the content of wilderness medicine courses for laypeople, as I teach them, are comprised of well-established first aid practices. The differences lie in the context in which we prepare our students to practice. We don’t train them to wait for the ambulance. We teach them to deal with challenging environmental conditions, to improvise, to be skilled with environmental illnesses and injuries, to focus on prevention, and to make decisions on if, and how urgently, a patient needs to see the doctor.

One of the few unique techniques in wilderness medicine is the concept of laypeople reducing dislocations. Early reduction often results in dramatic pain relief, reduces circulatory and neurological risks to the extremity, can allow for better immobilization and ease of transport.   It’s supported by the practice guidelines of the Wilderness Medical Society and many other wilderness medical experts and protocols. And as this real tale describes, can be very helpful to patient and rescuers.

One day last summer a participant on a NOLS wilderness trip slipped on an alpine snowfield and when self arresting with her ice axe suffered an apparent anterior dislocation of her shoulder, complicated by obvious diminished circulation to the extremity (no radial pulse) and a pale and tingling hand.

The course leader attempted to reduce the dislocation, however initial attempts with traction on the humerus were unsuccessful. He used a satellite phone to call his base, inform them of the situation and initiate an air evacuation. Complicating this situation was poor weather in this alpine cirque, including very high winds.   It was also evening, with only a couple of hours of daylight left.   The closest helicopter was approximately a 2 hour flight from the scene.

The air ambulance folks were in a difficult situation of appreciating the urgency of the medical situation, and knowing the weather conditions were marginal at best. This was a very real risk versus benefit decision.

While it was being debated, the base heard from the course leader that the shoulder was still dislocated and circulation to the extremity was still compromised. The course leader tried a different technique, lying the patient on a boulder and dangling her arm off the side with a bit of weight to fatigue the tight shoulder muscles.

After an hour, when the school's evacuation coordinators were approaching a deadline to make a go – no go decision, the phone rang. The trip leader was able to relay that the shoulder had relocated and circulation had returned to the arm. The local weather was still poor. He cancelled the request for the air evacuation. The patient was walked to the trailhead the next morning and has recovered nicely.

Herein lies the value of reducing a dislocation in remote circumstances. Without this tool the patient may have suffered a serious injury to her arm, and rescuers may have been put in harms way.

The field of wilderness medicine needs to continue to be thoughtful and wise about what we teach laypeople. We need to weight the risks of harm with the potential benefits and seek data to support what we do rather than relying on anecdotal experience. There are things we don’t want a WFR with an 80-hour training course and limited to no clinical experience to do in the field (e.g. suturing a wound), but the advice of experts, available data, and our experience (just ask any river professional), tells us that reducing a shoulder can be helpful if done carefully by a well trained wilderness medicine provider.

Defining Hypothermia

2007-12-12T16:09:00Z

Why is it taught that hypothermia occurs whenever someone is shivering or their temperature drops by a degree or two? I’ve read in several medical texts that the definition of hypothermia is a core body temperature below 95F(35C). (A question from a student in a course I'm teaching)

Yes, if you read the medical literature on hypothermia it’s common to see a threshold for hypothermia at 95F (35C). As a medical geek I like to probe the origins of stuff like this. The best I can figure this norm was described by British researchers in the 1960’s and has become a commonly shared criteria.

It’s fine and dandy for researchers or medical personnel with access to advanced life support to anchor their work at this point, but it’s not the world in which we manage hypothermia. We don’t work in rescue helicopters or emergency rooms with physicians, nurses and the benefits of medical technology, or inside a controlled physiology laboratory. We have to manage cold people in the wilderness.

We teach people to recognize hypothermia from subtle and early clues such as impaired ability to perform complex tasks, fine motor shivering, apathy, confused and sluggish thinking, slurred speech, stumbling, and "the umbles." We do this because we know it’s much easier to stay warm than to warm a cold person.

Compared to the scientist our definition of hypothermia is loose. We call people hypothermic who are probably only stressed by the cold, or are cold and unhappy, or who are simply having trouble coping with the environmental conditions. I’d imagine if we could measure the temperature of our “hypothermic” students we would find it only decreased a degree or two, if at all.

It doesn’t matter that our patient’s temperature may be higher than a clinical definition. It’s not important in the field to know the patient’s temperature. What’s important is to be self-aware of your physical state and vigilant of how your companions are faring in the cold. What’s important is acting early and aggressively to stay warm, rather than needing to rewarm to cold person. We can treat this early stage of hypothermia, these cold stressed people in the wilderness. A hypothermia wrap, a good meal and some warm fluids often are just what the doctor ordered. What we can’t afford to miss, because it’s much harder to manage in the field, is real hypothermia

The Milch Technique for Reducing a Shoulder Dislocation

2007-12-12T04:41:00Z

Medicine for the Outdoors Blog

by Paul Auerbach, M.D.

reposted with permission

This post is contributed by Dr. Jeremy Joslin, an avid outdoor enthusiast who is currently training to become an emergency physician.

Here goes:

After a long day trekking through Utah's canyon country, you decide to start heading back to camp. Three days from a car, and an hour away from camp, your hiking partner slips while stepping over a downed tree and catches his arm on the large trunk while falling. As he scrambles back to his feet, he cries out in pain and cannot seem to move his right arm at the shoulder. He knows the feeling, and tells you exactly what's happened: he's dislocated his shoulder again.

Anterior dislocation (where the head [or “ball” of the ball-and-socket joint at the shoulder] of the humerus, which is the large bone of the upper arm, is dislocated forward in relationship to the socket) is the most common type of shoulder dislocation and happens when the arm gets pulled away from the body quickly (abduction), as in the scenario above. Shoulder dislocations are quite painful, and if you are near medical attention, that's where you'll want to head. In the meantime, if you're sure the shoulder is dislocated, waste no time in “reducing” it (putting it back into place). Prompt reduction is beneficial for the joint.

In order to help determine if a shoulder has, indeed, been dislocated, I will reference the Wilderness Medical Society Practice Guidelines for Wilderness Emergency Care (2nd edition) (1), which lists these four features:

• Restriction of motion through the joint's normal range
• Obvious deformity in comparison with the uninvolved side
• Crepitus, or grating, of bone fragments is absent
• Often a typical, identifiable posture of the dislocated joint, which the patient will maintain to minimize pain

Once you've determined that the shoulder has been dislocated, you may want to attempt reduction. There are numerous methods of reduction for an anterior shoulder dislocation. My favorite technique for reduction is the Milch technique. Have the injured person sit, stand, or lie flat on his or her back, and then slowly reach, using the hand of their dislocated shoulder, behind their head and try to touch the opposite shoulder. Somewhere on the very slow, steady reaching, the shoulder will align itself and pop back into place. Another way to describe the positioning is to pantomime a pitcher's "wind up" before a pitch using the affecting side. Have the patient take their time and slowly reach upward and backwards as if they were going to pitch a baseball. If the "wind up" is slow enough, with plenty of rest if needed, you'll get the shoulder to pop back into place. This maneuver can be done solo or with assistance. If you are assisting, cup the victim’s elbow, giving it support and guiding their arm through the maneuver. Your other hand can be placed on their shoulder to apply support to the joint as it goes through the motion.

Why do I appreciate this maneuver so much? Here are my specific reasons:

• Compared with other maneuvers to reduce shoulders, this one seems to be the least painful. (2)
• Some medical providers swear that if the technique is done correctly and slowly, then the patient doesn't even need pain medication. (3)(4)
• It is easily described and easy to remember (the baseball pitch).
• It can be done for self rescue (just take your time and go as slow as possible).
• In my hands, this maneuver has been more successful than other techniques.

I'd like to hear about your favorite technique), or if you've ever needed to reduce a shoulder in the wilderness setting, how you achieved success. Finally, if you're interested in reading more about this very historic subject, begin by following the link to an interesting article.

Wilderness Medicine

Immersion Foot

Sea Bather’s Rash

Hands-Only CPR

Tick Attachment Sites

Wilderness Medical Society 25th Annual Conference

Picaridin-Based Insect Repellent

Avalanche Injuries

The Value of Wilderness Medicine Research

Treatment for Burns

by Paul Auerbach, M.D. reposted with permission from the Medicine for the Outdoors Blog

General First-Aid Principles

by Paul Auerbach, M.D. reposted with permission from the Medicine for the Outdoors Blog

Medical Decision-Making

NOLS Incident Database Paper Published

A Dislocation Tale

Defining Hypothermia

The Milch Technique for Reducing a Shoulder Dislocation

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog

by Paul Auerbach, M.D.

reposted with permission from the Medicine for the Outdoors Blog