Great White Shark Adventure

Two weeks ago, I traveled to Guadalupe Island off the Pacific coast of Mexico to join a wonderful group of divers on a dive expedition aboard the M/V Nautilus Explorer to benefit the Historical Diving Society. The diving purpose of our journey was to photograph and video great white sharks underwater, and I'm happy to report that the adventure was a resounding success.

Led by guests Rodney Fox (the most famous shark attack survivor) and Zale Parry (the co-star with Lloyd Bridges of the television show "Sea Hunt"), the trip was arranged by Ed Stetson Diving and Charters. We met in San Diego, enjoyed a bus ride across the border to Ensenada harbor, boarded the vessel, and motored to our sheltered mooring adjacent to the coast of Guadalupe Island. Fortunately, there were few medical concerns, other than a bit of seasickness (which I will discuss in a subsequent post) and feeling waterlogged after spending nearly 20 hours underwater over three days. The latter was, of course, voluntary, and precisely the reason why this was such a fabulous expedition.

Here is a description of the trip:

This was the second benefit expedition to dive with the white sharks at Guadalupe Island. All the proceeds from this trip were donated to the Historical Diving Society.

Guadalupe Island is a very remote island located 210 miles south of the Mexican border and 150 miles off the Baja Peninsula. The ocean voyage to reach the island was approximately 18 hours each way. On the way out, we followed a storm, so the beginning of the crossing was a bit bouncy, but over the course of the next 24 hours, the seas flattened out, so that we had calm waters for the shark cage diving, and a very smooth return crossing.

Guadalupe Island is 22 miles long and 8 miles wide. The island is home to about 80 people - primarily commercial abalone divers, lobster fishermen and their families. There is a very small school on the island for the 22 children. California sea lions, elephant seals and Guadalupe fur seals have rookeries on the island. There was no shortage of these animals, both on shore and swimming in the water, apparently oblivious to the danger lurking from below. Guadalupe Island was recently declared a Biosphere Preserve by the Mexican government. Passenger planes are no longer permitted to land on the island, so the only way to get to the island is by sea. It is now under the guidance of the Comision Nacional de Areas Naturales Protegides (CONANP). Sportfishing around the island is restricted and white shark diving is now well regulated. This protects the resources, the divers and the people who live on the island. Conservation is extremely important, because we know that shark populations worldwide have been decimated. It has been stated that the jaws of a great white shark sell for U.S. $30,000 or more.

There is a population of over 100 white sharks that live around the island. They range from about 12 to 18 feet in length, but a few juveniles have recently been spotted. They feed primarily on yellowfin tuna and an occasional seal or sea lion. In the winter, some of the sharks dive deep and travel to Hawaii. Others move to the mid Pacific at a congregation location, and others remain around the island. The migrating sharks return to Guadalupe around September. Various research programs are studying the white sharks at Guadalupe Island. It has been discovered that these sharks do not travel between the Farallon Islands and Guadalupe Island. The white sharks at Guadalupe are very curious, yet cautious. They don’t ram the cages as depicted on TV. However, we did have a few sharks nibble on the cages, and one juvenile shark flew from the water in its breaching behavior. Cage biting behavior is usually a result of pulling the bait directly toward the cage as the shark is chasing it. Great care is taken to not harm the sharks.

The M/V Nautilus Explorer was custom built in 2000 specifically for diving. The vessel’s homeport is Vancouver, British Columbia. We enjoyed a wonderful crew of 10 that included divemasters and 2 chefs. The Nautilus dives the summer in Alaska / British Columbia and works in Mexico during the winter: Guadalupe Island, Sea of Cortez and Socorro Island. The ship is 116 feet long and incorporates features not usually found on dive boats, including a very important hot tub. After being underwater in 70-degree F water for 4 hours at a time, I can vouch for how good it feels to gulp a few cups of hot chocolate while floating in the hot tub. You have to get that core body temperature up, so that you can get back in the water and not miss any of the action!

The weather was awesome, and the water visibility was excellent. It is typically between 70 to 120 feet in very blue water. We anchored in 250 feet of water about a quarter mile from shore. For the dive cage operation, there were three cages tied to the stern and another "boom cage" hung off the starboard stern. In addition, there was a cage that was raised and lowered on cable, for which we took turns diving to 40 feet, to get to another level and more sharks, often quite large. We saw a couple of animals that approached 18 feet in length.

When I saw my first great white shark, it was pure excitement. When I saw my first 18 footer, it was like seeing a living locomotive. It is difficult to describe just how massive and powerful are these magnificent creatures. When they turn in the water, they bank like an airplane, and glide through the water with total mastery of the medium. There is no question that they reign supreme, more so than any creature I have ever witnessed.

Because we were standing in cages, we wore full wetsuits or dry suits, hoods, booties, gloves and a mask. To keep from floating, we wore heavy (40 to 50 pounds) weight belts or harness systems that allowed us to stand or kneel on the bottom of the cage. Air was pumped to each diver via a surface supplied hookah system with a second stage regulator. Emergency tanks and regulators were located in each cage.

The shark cages were specially designed for that purpose. Each cage could hold three divers, and they were constructed of schedule 80 steel. There were flotation tanks inside the top of the cages for added protection. The tops of the surface cages floated about 2 feet out of the water; the divers' heads were about 3 feet below the surface. We entered the cates through a door on the top then climbed down a ladder into the cage.

Viewing a shark from the boat deck was almost as amazing as viewing one underwater, because as we watched them glide around the cages, we could appreciate their massive size in comparison to the cages and comparatively small humans. I was fortunate to get a few wonderful photos and videos, which I will use for teaching purposes and entertainment.

For those of you interested in shark attacks, here is a brief bit of information, which was not needed by us during our trip to Guadalupe Island!

The jaws of some sharks contain rows of razor-sharp teeth, which can bite down with extreme force. The result is a wound with loss of tissue that bleeds freely and can lead rapidly to shock. Even if a shark bite appears minor, the wound should be washed out and bandaged, and the victim taken to a doctor. Often, the wound will contain pieces of shark teeth, seaweed, or sand debris, which must be removed in order to avoid a nasty infection. Like other animal bites, shark bites should not be sewn or taped tightly shut, in order to allow drainage. This helps prevent serious infection. The victim should be started on an antibiotic to oppose Vibrio bacteria (ciprofloxacin, trimethoprim-sulfamethoxazole, or doxycycline).The skin of many sharks is rough like sandpaper, and can cause a bad scrape. If this occurs, it should be managed like a second-degree burn, with antiseptic ointment and a dressing.

If you wish to avoid sharks (which is not what we wished to do...):
1. Avoid shark-infested waters, particularly at dusk and after dark. Do not dive in known shark feeding grounds.
2. Outside of cages designed to protect you from sharks, swim in groups. Sharks tend to attack solitary swimmers.
3. When diving, avoid deep drop-offs, murky water, or areas near sewage outlets.
4. Do not tether captured (speared, for example) fish to your body.
5. Do not corner or provoke sharks.
6. If a shark appears, leave the water with slow, purposeful movements. Do not panic or splash. If a shark approaches you while you are diving in deep water, attempt to position yourself so that you are protected from the rear. If a shark moves in, attempt to strike a firm blow to the snout.
7. If you are stranded at sea and a rescue helicopter arrives to extract you from the water, exit the water at the earliest opportunity.

None of this, of course, came into consideration during our adventure, because we were protected at all times and very cautious. Indeed, we all came away from our experience being much more committed to conservation and appreciating more than ever the wondrous nature of life in the wilderness. We must do everything possible to increase our understanding and support for preserving essential species like the great white shark.

photo by Paul Auerbach, M.D.

Tags: great white shark, white shark, Guadalupe Island, wilderness medicine, outdoor medicine, healthline

Labels: great white shark, Guadalupe Island, Historical Diving Society, shark

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Thank You to Emergiblog for Grand Rounds

Thank you to Emergiblog for including my post about rapid treatment for a stroke in this past week's edition of Grand Rounds. Grand Rounds is a weekly compilation of posts related to health care compiled by a host, who makes a great effort to present them in an informative and entertaining manner.

Labels: Emergiblog, Grand Rounds

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Rapid Treatment for a Stroke

On September 25, 2008, there was an article published in the New England Journal of Medicine entitled, "Thrombolysis with alteplase 3 to 4.5 hours after acute ischemic stroke." Alteplase is a "clot buster" drug used to dissolve blood clots that form in vital small blood vessels such as those that supply the heart and brain. Based on the findings of Dr. Werner Hacke and other investigators who participated in this reported study, thrombolysis (dissolving a blood clot) for stroke can be safe and effective up to 4.5 hours after the onset of stroke symptoms. But we must never lose sight of the fact that the sooner treatment is administered, the better.

Up until the publication of this article, the recommendations for treatment of acute stroke mandated that thrombolytic therapy only be given within 3 hours after the onset of symptoms. This is generally done in emergency departments, commonly associated with "stroke centers." It is not trivial therapy and needs to be done after a computed tomography (CT) scan of the brain confirms that the stroke is caused by diminished blood flow beyond an occluded blood vessel, rather than by a ruptured or leaking blood vessel. So, time is of the essence in transporting a victim of a suspected stroke to a hospital capable of obtaining a CT scan and then applying this therapy.

Why am I writing about this in a blog devoted to outdoor health? Because stroke is a devastating event, and victims may have the onset of symptoms while they are outdoors - perhaps jogging, swimming, climbing, or lifting a pack. If they are fortunate enough to be within the range of rapid transportation to a qualified center, then perhaps they can be rescued from a lifetime of disability.

A few previously published studies showed a trend toward good outcomes with later treatment, but until this current study was published, the data were not sufficiently conclusive to warrant changing the recommendations.

In the primary article and in the editorial in the New England Journal of Medicine that was solicited to accompany the article, the authors stress that having a larger treatment window (expanded from 3 hours to 4.5 hours after onset of symptoms) should not make anyone complacent in terms of seeking evaluation and care as soon as possible. In the editorial, it is noted that "every minute matters" during stroke treatment - the sooner that someone is treated, the more likely that the outcome will be the best that could be achieved. One never knows the moment at which the devastation caused by a stroke becomes irreversible.

Here is some information from the book Medicine for the Outdoors about stroke:

A stroke is caused by a blood clot that blocks an artery supplying part of the brain, or by bleeding from a leaking vessel into the brain. It occurs suddenly and can be minor or major, depending on the area and amount of the brain involved. If a stroke involves the brainstem, it may affect the breathing center and cause rapid death. A stroke may be caused by rupture of a cerebral artery aneurysm; when this occurs, the victim may suffer from a form of bleeding known as subarachnoid hemorrhage, in which case the victim typically complains of the “worst headache of my life.”

Symptoms include sudden headache without another cause, numbness of the face/arm/or leg, nausea, vomiting, blurred or double vision, weakness or paralysis of the arm(s) and/or leg(s) (particularly if it occurs on one side), difficulty speaking or understanding speech, difficulty walking, dizziness, confusion, loss of balance or coordination, loss of consciousness, coma, seizure, and collapse. If someone has stroke symptoms that last for a few minutes to an hour and then gradually resolve, he has suffered a transient ischemic attack (TIA), which is a warning that he may soon suffer a full-blown stroke. Even if stroke symptoms are fleeting, the victim should see a physician as soon as possible. If a person is felt to have suffered a TIA, he should begin to take aspirin, 50 to 325 mg by mouth once a day, until he is evaluated by a neurologist. If a stroke occurs or is strongly suspected, aspirin should not be administered.

A rapid simple neurological examination may reveal subtle changes indicative of a stroke. This exam consists of the following:

Mental status. Ask the victim his name, age, and location, as well as time, day, and year.
Vision. Have the victim count fingers that you display. Check each eye by itself and then both eyes together. Check that the pupils are equal. Ask the victim to follow a moving object with his eyes.
Facial muscles. Ask the victim to pucker his lips, and then to whistle. Check the cheeks and mouth for symmetry. Have the victim clench his jaw while you feel the jaw muscles on each side. Have the victim tightly close his eyes. Have him relax with his eyes closed; lightly touch his face to locate any numb spots.
Hearing. Make a soft noise (yet loud enough that you can hear it) in each of the victim’s ears.
Swallowing and speech. Ask the victim to swallow. Ask him to stick his tongue out and move it from side to side voluntarily. Listen carefully to note if his speech is clear or slurred.
Muscle strength. Have the victim squeeze one of your fingers with each hand, straighten each leg against resistance, bend each leg against resistance, bend and straighten each elbow and wrist against resistance, extend and flex each ankle against resistance, and shrug both shoulders against resistance.
Sensation. Using a light touch, move your fingers over the entire body and try to identify any areas of decreased sensation.
Coordination. Ask the victim to stand perfectly still in an upright position with his eyes closed and his arms at his sides. Be prepared to catch him if he begins to fall. Have him open his eyes, then clap one hand into the palm of the other as fast as possible. Ask him to move an index finger back and forth between the tip of his nose and your finger, held 18 in (46 cm) away. Have him walk heel-to-toe and on tiptoes.

If someone displays the symptoms of a stroke, he should be placed as best possible at absolute rest with his upper body and head elevated by an angle of at least 30 degrees. If his level of consciousness declines, pay attention to his airway so that he does not vomit and choke. Seek immediate medical attention. Low blood sugar may cause symptoms that mimic a stroke. If the victim can swallow purposefully without choking, sugar granules or concentrated liquid glucose (Glutose: one tube contains 25 g) can be inserted under the tongue, to dissolve and be passively swallowed.

If stroke symptoms are associated with scuba diving, they might indicate an air embolism. In this case, the victim needs to be transported in a head-up and/or left-side-down position and delivered to a recompression (hyperbaric) chamber as soon as possible.

image courtesy of jama.ama-assn.org

Tags: stroke, thrombolysis, alteplase, wilderness medicine, outdoor medicine, healthline

Labels: alteplase, cerebrovascular accident, stroke, thrombolysis

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Bolin Chest Seal

At the most recent continuing medical education (CME) meeting of the Wilderness Medical Society, Carl Weil exhibited on behalf of Wilderness Medicine Outfitters. One of the products he displayed was the Bolin Chest Seal, which is a novel product that simplifies field management for a penetrating ("sucking") chest wound, in which there is a persistent leak that not only causes a lung to collapse, but for air (sometimes with blood) to accumulate under pressure within the chest cavity between the external surface of the collapsed lung and the inside of the chest wall.

The usual teaching for improvisational management of chest wounds is that all open wounds (particularly those in which air is bubbling) should be rapidly covered, to avoid “sucking” chest wounds that could allow more air to enter the pleural space and thus continue to worsen a collapsed lung. For a dressing, a Vaseline-impregnated gauze, heavy cloth, or adhesive tape can be used. The dressing should be sealed to the chest on at least three sides. If the victim develops a tension pneumothorax (collapsed lung under pressure) following a penetrating wound to the chest and his condition deteriorates rapidly (difficulty breathing, blue skin discoloration, distended neck veins, collapse followed by unconsciousness), force a finger through the wound into the chest to allow the air under pressure to escape. If your diagnosis is correct, you will hear a hissing noise as the air rushes out. This allows the lung to partially expand and may save the victim’s life. After the release of air from a tension pneumothorax, cover the wound with a dressing and seal only three sides to create a flutter-valve effect (air can exit, but not enter) and prevent a recurrence, which might come with a complete seal.

The Bolin Chest Seal is a substitute for the above improvisations. It is designed for medical professionals, but since I have discovered that there is a substantial number of readers of this blog who fall into this category, it is useful to provide a brief description here. As advertised, "The BCS is a sterile occlusive chest wound dressing for treating open pneumothorax and preventing tension pneumothorax that result from gunshots, stabwounds, or other penetrating chest trauma. The patented failure-proof triple-valve design of the BCS allows air and blood to escape while preventing the re-entry of either, thereby eliminating any unwanted gas or liquid exchange at the trauma site.

The large (6” diameter), rugged polyurethane disc structure of the BCS can cover practically any size chest trauma site. The thickness of the disc prevents any disc wrinkling from occurring during application. In addition, the wound side of the disc is covered with a thick layer of jell-based adhesive, strong enough to not only seal over hair and blood but also flexible enough to be removed and reapplied to the trauma site if required."

This is a useful product to add to the armamentarium of the field responder who might need to manage significant chest trauma.

If you're going to be outfitting for an outdoor adventure or expedition, you can find much of what you need betweenWilderness Medicine Outfitters and Chinook Medical Gear, Inc. I couldn't find the Bolin Chest Seal at the Wilderness Medicine Outfitters website, even though it was on display at their booth, so the link above will take you to Chinook Medical Gear.

Tags: Bolin Chest Seal, chest wound, pneumothorax, wilderness medicine, outdoor medicine, healthline

Labels: Bolin Chest Seal, Carl Weil, chest wound, Chinook Medical Gear, Wilderness Medicine Outfitters

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Thank You to Pallimed for Grand Rounds

Thank you to Pallimed for including my post from a series about desert survival based on the expertise of Dr. Mel Otten in this past week's edition of Grand Rounds. Grand Rounds is a weekly compilation of posts related to health care compiled by a host, who makes a great effort to present them in an informative and entertaining manner.

Labels: Grand Rounds, Pallimed

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Thank You to Notes of an Anesthesioboist for Grand Rounds

Thank you to Notes of an Anesthesioboist for including two of my posts - a post from a series about desert survival based on the expertise of Dr. Mel Otten and a post about the presence of toxic metals in Ayurvedic medicines available on the web - in this past week's edition of Grand Rounds. Grand Rounds is a weekly compilation of posts related to health care compiled by a host. The host did an excellent job of presenting a wonderful collection of information in an informative and entertaining manner.

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The Desert and Desert Survival 4

This is the sixth post based upon educational sessions and syllabus material presented at the Wilderness Medical Society Annual Meeting & 25th Anniversary held in Snowmass, Colorado from July 25-30, 2008. This post continues the discussion about the desert and desert survival, based upon the extensive knowledge of Dr. Edward J. (“Mel”) Otten, who is Professor of Emergency Medicine and Pediatrics, and Director of the Division of Toxinology at the University of Cincinnati.

Desert shelters are of three main types: 1) Natural shelters are caves and rock overhangs. When using natural shelters, remember there may already be other inhabitants that need eviction. Rattlesnakes, tortoises, ground squirrels, lizards, andskunks often use caves and other cool areas during the heat of the day. They may be sources of food, but are also potentially dangerous to humans. Some reptiles are venomous and many mammals carry rabies or plague. They can usually be removed with a stick or dispatched with a rock. 2) Man-made shelters include tents, vehicles, and buildings. Most vehicles become very hot and may hasten heat illness and dehydration. It is better to sit in the shade of an automobile than to be inside it during the heat of the day. Tents and buildings are best if there is adequate ventilation. 3) Improvised shelters are typified by the desert trench shelter, shade shelter or lean-to. Any structure that provides shade, protection from wind and blowing sand, and decreases heat gain or loss is minimally adequate.

The hottest area in a desert climate is at the surface of the ground, so getting above the ground or below the ground decreases exposure to the highest temperatures. Most desert animals take advantage of this fact by their behavior. Birds perch high in trees in the shade of a branch or in some cases inside of a cactus. Most mammals and reptiles will burrow into the ground, where just three feet below the surface the temperature may be 30% cooler. Humans can imitate this behavior by construction of a desert trench shelter. This is a trench dug in the ground 2 to 4 feet wide and 2 to 3 feet deep and about 6 feet long. A barrier can be made of any cloth material at hand, such as a blanket, sheet, poncho, tarp, or space blanket. This barrier is placed over the trench, about 18 inches above the bottom and the sides are weighed down with rocks or sand. Another similar barrier ( the first one can be doubled back on itself if it is large enough) is about 12 to 18 inches above the first barrier and also weighed down. This construction creates an insulating barrier that traps cooler air in the bottom of the trench and reflects solar radiation from the top. Ideally a reflective space-type blanket is used for the outer layer, which will increase the amount of heat reflected .

Removing the seat from a vehicle and sitting above the ground in the shade of the vehicle or constructing shade with a blanket or tarp and available materials can provide some shelter in the heat of the day until a more adequate shelter can be built. At night, when temperatures drop, the shade trench remains warmer due to heat produced by the inhabitant. The top barrier, with its reflective surface, can be reversed to reflect heat back into the trench. Any insulating material can be added to the floor of the shelter to decrease heat loss to the ground. Given enough time, shelters such as a tepee, tent or lean-to can be constructed using tarps, blankets, parachute panels, or other materials. Construction should take place in the cooler times of the day to conserve sweat and water. If you have a reliable source of water, such as a desert water hole or ”tank” (natural collection of water in nonporous rock) then it is best to stay where you are and try to be rescued rather than attempting to travel large distances without adequate water.

Food is not as immediate a problem as water in the desert. Most humans have an extra 50,000 to 70,000 calories that they store in the form of fat, and can exist for weeks without eating. Food in the form of animals or plants is usually available if water is available. Cactus fruit, such as prickly pear, can be eaten when peeled. Legumes such as acacia, mesquite, and palo verde produce beans that can be crushed and mixed with water to form tortillas. Yucca stems, cattails, agave stems and prickly pear pads can be cooked and eaten. Avoid plants with milky saps or red berries, and other plants that cannot be positively identified as edible. Mushrooms should not be eaten. It is essential to become familiar with the common poisonous and edible plants in any area through which you will travel. Insects, bird’s eggs, grubs, tortoises, and other slow movers can be captured by hand. Most small animals, such as snakes, lizards and birds, can be killed with a rock or stick. Jackrabbits, ground squirrels, and rats may be snared or trapped. Large mammals should be avoided, as the likelihood of killing one of these without a firearm is small, while the likelihood of becoming a casualty is high. All meat should be cooked or dried prior to ingestion. Animals avoid as food or in general include caterpillars, spiders, scorpions, centipedes, millipedes, toads, and bats, as well as some mammals that carry plague, tularemia, Hanta virus and rabies.

In addition to the hazards of heat and dehydration, there are other hazards that one may encounter in the desert. Blowing sand and dust created by vehicle traffic may cause eye, nose, mouth and skin irritation. Desert winds up to 100 mph can blow for days, creating immense sandstorms and dust storms that can cover large areas reducing visibility to near zero. In addition, vehicles, tents and buildings can be demolished and roads obliterated. Sandstorms blowing for days have caused destruction in cities such as Melbourne and Bagdad. Exposed skin must be protected and getting to hard sided shelter such as a building is preferable. The possibility of an individual being buried is remote but drifting sand can block doors and strand vehicles.

Quicksand is another hazard that travelers must watch. There are two types of quicksand: 1) A mixture of sand and water found along the shores of lakes and seas and estuaries of rivers. This type make appear solid, but is a suspension of fine sand and water and cannot compact. 2) Fine sand deposited by wind in hollow depressions. Depending on the depth of the depression one could sink 15 to 20 feet. If one is caught in quicksand, attempt to escape by flattening out and swimming to firm ground. Most quicksand ,areas are small. Animals will panic and struggle hastening their submersion. A rescuer can usually pull the victim to firm ground using a rope, belt or strap. Removing one’s pack and throwing it to firm ground will also allow for easier escape.

Animal hazards include venomous snakes and arthropods, carriers of zoonotic illnesses, and large mammals. Plant hazards include poisonous varieties that may cause dermatitis or systemic symptoms if ingested. Many types of plants produce spines, thorns, which when broken off in the skin, commonly cause infections.

Even in the best of circumstances, hiking in the desert can be difficult. Most modern travel is performed with high clearance, 4 wheel drive vehicles. These vehicles should have sand mats (for added traction in soft surfaces), and a winch and cable for self-extracting the vehicle or rescuing another vehicle. Extra water, spare parts for the vehicle ( fan belts, hoses, spark plugs, fuses, bulbs), additional fuel and oil, shovel, two jacks, spare battery, spare tires and tire patching materials, radio and tool kit are mandatory in desert travel. Traveling in convoys is a must both for safety and in someplaces, security. Salt flats, mud flats and soft sand can bog down even 4 wheel drive vehicles. Never attempt to cross arroyos or wadis when they are flooding.

Many areas have no access to wheeled vehicles and travel by camel, donkey, or horse is still common. Camels are still the most efficient desert transportation and can travel for long periods without food or water . They also are more resistant to blowing sand, heat and temperature changes. Expert assistance is needed for travel by camel. Horses and donkeys are limited to short distances and require more food and water. Current topographic maps and a good compass are essential whether traveling by vehicle, animal, or on foot. Local authorities should be consulted concerning water sources; these should be marked on the maps. A copy of the map should be left with someone who knows your plans. Your route and campsites should be indicated on the map. In that way, if one becomes lost or injured the search and rescue teams will know where to initiate the search.

If one becomes lost or injured, it is usually best to stay in one place and signal for help, using a mirror or other reflective object during the day and a fire at night. Cellular telephone, radio, or emergency locator transmitter may aid searchers. Flares and whistles should be used only when searchers are nearby or a search aircraft is moving in your direction. Geometric patterns drawn on the ground, such as “SOS”, “HELP” or a large “X”, may aid aircraft in identifying the position of a distressed person. Rocks, contrasting soil, plants, or clothing can be used to produce the patterns. It is difficult to see a single human being on the ground; therefore, it is always best to stay near a vehicle if possible. An automobile can be a good source of signaling equipment. The windscreen and windows reflect light, and the mirrors can be removed and used to signal. Oil can be drained, placed in a hubcap, and mixed with sand. When set on fire it produces dense black smoke. The hubcaps can be used to dig a desert trench shelter, the battery to start a fire, and the seat covers and floor mats for shelter and footwear. If one has adequate water, knows the direction of travel, has good footgear, and decides to try to walk to safety, it is imperative to leave a note outlining plans in a conspicuous place or to draw an arrow on the ground with rocks pointing in the direction of travel. Direction finding can be accomplished without a compass using the sun or stars.

Before traveling in the desert, it is best to know the location of the key terrain features, such as rivers, highways, mountain ranges, and cities. Power lines, stream beds, and pipelines may also lead to civilization, but it may require days to arrive. It is dangerous to travel through arroyos or wadis because of the danger of flash flooding. Rainfall in mountains several miles away can wash down these formerly dry stream beds, pushing tons of mud, rocks and water in a lethal torrent. Sand dunes should be avoided because of the amount of energy required to traverse them and salt marshes may contain soft ground that traps the hiker. Travel in the cool of the night to conserve water and use the stars for direction. The dangers at night are that many desert animals are more active and the chance of falling from a cliff, stepping into a hole or stumbling into a cactus is greater.

image courtesy of unmuseum.org

Tags: desert survival, desert, survival, wilderness medicine, outdoor medicine, healthline

Labels: desert, survival

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BleedArrest

I had the misfortune this past week to stop some bleeding on my body from a small cut vein. Like many people, I ingest one baby aspirin a day to inhibit platelet activity in pursuit of "heart health." This has the side effect of sometimes making me bleed more from small cuts and nicks, or get a larger bruise when I bump into something. So, this time I got caught on a fence and tore some skin directly over a tiny vein (a "spider"), which bled freely. I applied pressure for a few minutes with a paper towel, but the bleeding continued. Then I applied firmer pressure for 10 minutes with a wadded gauze pad, but the bleeding continued. Finally, I applied hard pressure with the heel of my hand on top of a roll of gauze. No luck.

Ordinarily, I would sit around for 30 minutes applying pressure, but I thought this might be a great opportunity to test out a sample of a product I had been sent for evaluation. BleedArrest powder (from Hemostasis, LLC) is composed of tiny hemostatic particles that contain amylopectin, a natural clotting polymer. The sample I was given came in a small plastic bellows applicator from which one easily squeezes out the desired amount of particles.

The instructions read:

1. Tear open BleedArrest pouch and remove applicator.
2. Blot excess blood from the wound with gauze pad.
3. Apply liberal amount of BleedArrest particles to cover wound.
4. Using gauze, apply firm pressure to the wound for 5 minutes. If bleeding continues, apply more BleedArrest and repeat Step 4.
5. Wrap and secure bandage around wound to maintain pressure. Discard any unused product after opening.

BleedArrest is intended to help stop moderate to heavy bleeding. It was a good choice for my small bleeding vein. After I applied a pile of the particles and applied pressure, the bleeding stopped for the most part, but I could see that there was still a small amount of fresh blood welling up through the medical dust. I followed the instructions and reapplied another pile, and after the second 5 minutes of pressure, the bleeding stopped. It was easy to brush off the wound in the perimeter around the bleeding point, and then to cover it all with a Coverlet elasticized bandage.

Based on my experience with the product, I'm going to add it to my traveling first aid kit, particularly for outdoor excursions. BleedArrest also comes in a foam preparation, which in certain applications would be easier to use than powder.

Tags: BleedArrest, bleeding, hemostasis, wilderness medicine, outdoor medicine, healthline

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The Desert and Desert Survival 3

This is the fifth post based upon educational sessions and syllabus material presented at the Wilderness Medical Society Annual Meeting & 25th Anniversary held in Snowmass, Colorado from July 25-30, 2008. This post continues the discussion about the desert and desert survival, based upon the extensive knowledge of Dr. Edward J. (“Mel”) Otten, who is Professor of Emergency Medicine and Pediatrics, and Director of the Division of Toxinology at the University of Cincinnati.

Survival Kit:

The survival kit must be carried at all times, have quality equipment and supplies, and be protected from the elements. Each item should have multiple uses if possible. There must be items that can be used for shelter, signaling, fire building, first aid, and other uses. Many items will routinely be carried by most hikers and backpackers, but some specialized items should be added. One’s clothing is the basic survival shelter and if properly selected will be the first step in protection from the climate. General use items include a Swiss Army knife with as many blades as possible. The “Swiss Champ” includes among many other features a magnifying glass, which is quite useful for removing cactus spines or starting fires. Parachute cord (eight strand) has multiple uses, including shelter construction, creation of snares, and fishing nets and lines. A signal mirror, whistle, matches/ metal match/lighter, first aid supplies, compass, safety pins, water disinfection tablets, and plastic bags can be stored in a relatively small container that should be kept on one’s person at all times. The first aid kit should contain bandages, insect repellant, sunscreen, lip balm , antiseptic ointment, aspirin,
antihistamines, tape, and any prescription medications.

The desert survival kit should include a 5 foot by 5 foot piece of plastic , 4 foot length of plastic tubing, and metal cup (all for making a solar still), emergency blanket ( silver on one side, red on the other), extra sunglasses/eye protection, nylon canteen (minimum 5 quart size), and extra sunblock.

The “Rule of 3’s” gives us a priority list for the survival. One can live three minutes without oxygen, three hours without warmth, three days without water, and three weeks without food.

Water:
The key to desert survival is water. Unfortunately water weighs 8 pounds (3.6 kg) per gallon( 3.8 L) and each individual needs up to 2 gallons (7.6 L) per day. Always carry as much water as possible. Collapsible canteens can carry several quarts of water and keep it cooler ( because the surface heat absorption to volume is less ) than can hard plastic or metal. Drink at every stop and while hiking if using a drinking tube. Flavoring and cooling water increase palatability and thus consumption. Most hikers do not carry enough water for more than one day, so having a method for acquiring water is mandatory. Solar stills, vegetable stills, digging along arroyos and in dry lake beds, wiping dew from plants in the early morning, and extracting water from succulent plants are all methods for obtaining water in a desert survival environment, but minimal water may be acquired by these methods.

While there are a number of methods for obtaining water in the desert,
minimizing water loss is an essential strategy for a human with limited water resources. All desert plants and animals have developed adaptive mechanisms for conserving water and humans, if the are to survive, must develop strategies for conserving their sweat, not their water. While this may be intuitive, most desert travelers neither limit their travel to cooler times of the day nor their work activities to the shade. Employing a strategy of resting in the shade from 1000 hours until 1500 hours, drinking adequate water based on the appearance of the urine (see below), and keeping as much skin covered as possible has decreased the number of heat casualties in the military during training exercises.

While thirst and amount of sweat on clothing are poor indicators of hydration status, the color and amount of urine produced can roughly estimate it. The darker the urine, the more concentrated and the greater the degree of dehydration. If potable water is available, it should be consumed; it is better to conserve sweat rather than water. If there is a limited amount of water , food should not be eaten unless the food contains a large amount of water. The metabolism of food, especially protein and fat, and excretion of waste products requires potentially unnecessary consumption of water. Only potable water should be drunk, because vomiting and diarrhea caused by contaminated water could quickly become fatal in the desert. Water obtained from lakes, streams, wells, or springs should be considered contaminated and must be made potable prior to drinking. Water holes may attract dangerous game as well as potential food.

Desert water may be found by looking for animal sign, such as trails or spore. Some plants, such as cottonwood, sycamore, willow and cattails, may be indicators of water. Water may sometimes be found by digging at the outside bend of a dry riverbed or stream (arroyo and wadi are terms used to indicate rain run-off channels that may contain water during the rainy season). Rainwater, dew and water obtained from a solar or vegetable still is relatively potable. Urine, seawater, alkaline pools and brackish water should never be drunk. They contains large amount of solutes that would require more water to excrete than they contain and hasten dehydration and renal failure. Liquid from automobile radiators is contaminated with glycols and should not be drunk or used in solar stills. Many plants, such as barrel cacti and traveler’s tree, and animals such as the desert tortoise contain water that can be extracted in an emergency.

A solar still may yield a small amount of water. It can be constructed by placing a 5 feet by 5 feet piece of clear plastic over a hole 3 to 4 feet in diameter and dug 3 to 4 feet deep in the ground into which vegetation, urine, or brackish water has been placed. Solar energy causes water to evaporate within the hole and collect on the underside of the plastic. Because it cannot escape it will drip back into a container placed at the bottom of the hole. A tube can be attached to the inside of the container so that the water can be drunk without dismantling the still. A plug should be put in the drinking end of the tube to prevent clogging. The amount of water produced depends on the amount of moisture in the hole, amount of sunshine directed at the still, and the size of plastic sheet. A still dug into a dune or dry sand will not produce much water. Dew, rainwater and edible animals may fall into the still as a bonus. Moisture can be wiped off of plants during early morning and can be squeezed from the pulp of certain plants, such as yucca. Milky, bitter, or sour pulp should not be used and the pulp should not be eaten. Water can be made potable by boiling or using filters or chemicals.

Tags: desert survival, desert, survival, wilderness medicine, outdoor medicine, healthline

Labels: desert, solar still, survival, Swiss Army knife

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Thank You to M.D.O.D. for Grand Rounds

Thank you to M.D.O.D. for including my post in a series of posts about desert survival based on the expertise of Dr. Mel Otten in this week's edition of Grand Rounds. Grand Rounds is a weekly compilation of posts related to health care compiled by a host. This week's host has done a terrific job tying together a diverse set of posts in an informative and entertaining manner.

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Toxic Metal Content of Ayurvedic Medicines Available on the Web

The naturopathic approach to health and wellness often involves administration of medications with which Western medical practitioners are not familiar. Furthermore, these drugs, available both in the U.S. and abroad, are not regulated to the same extent as are drugs manufactured in the U.S. This fact does not per se make them less effective or dangerous, but adds an element of the "unknown" to their use by practitioners and patients.

With the advent of the Internet, people have access to a great many drugs, medical devices, and other remedies more readily than ever before. We are certainly aware that it is safest to operate under the assumption of "buyer beware," but the information available by which to judge the purity and effectiveness of drugs and remedies is commonly incomplete and imperfect. So, whenever there is useful information about efficacy and safety, we should welcome it with an open mind.

In a recent issue (Volume 300, Number 8, pages 915-923, August 27, 2008) of the Journal of the American Medical Association (JAMA), Robert Saper, M.D. and his colleagues published a paper entitled, "Lead, Mercury, and Arsenic in US- and Indian-Manufactured Ayurvedic Medicines Sold via the Internet." They used a search via 5 Internet search engines to identify 25 Web sites offering traditional Ayurvedic herbs, formulas, or ingredients commonly used in Ayurveda, indicated for oral use and available for sale. They identified 673 products, from which they randomly selected 230 medicines for purchase. The concentrations of metals within these products were measured using a technique known as x-ray fluorescence spectroscopy.

The results were quite revealing. Of the products sampled, approximately 20% showed detectable (and therefore, unacceptable) levels of lead, mercury, or arsenic. All of the metal-containing products contained enough metal to exceed one or more standards for acceptable daily human intake of toxic metals. It didn't matter whether or not the products were manufactured in the U.S. or in India - the findings were approximately the same.

Rasa shastra medicines, which traditionally combine herbs with metals, minerals, and gems, had a higher prevalence of metals than did non-rasa shastra types, which only contain herbs.

In their discussion, the authors cited case reports of metal toxicity and called for government-mandated limits on toxic metals in dietary supplements as well as independent testing to confirm manufacturers' claims. These conclusions seem quite reasonable given what was discovered by this study.

Many foreign and wilderness travelers, as well as people who seek "alternative medicine" remedies domestically, are faced with a panoply of drugs and products advertised to improve health. You should be very careful about what you ingest, and do some homework about what is contained in each and every product you ingest before you decide to eat or drink it.

image courtesy of IMIS Pharmaceuticals

Tags: Ayurvedic medicine, toxic metal, rasa shastra, wilderness medicine, outdoor medicine, healthline

Labels: arsenic, Ayruvedic medicine, lead, mercury, metal, rasa shastra, toxic metal

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The Desert and Desert Survival 2

This is the fourth post based upon educational sessions and syllabus material presented at the Wilderness Medical Society Annual Meeting & 25th Anniversary held in Snowmass, Colorado from July 25-30, 2008. This post continues the discussion about the desert and desert survival, based upon the extensive knowledge of Dr. Edward J. (“Mel”) Otten, who is Professor of Emergency Medicine and Pediatrics, and Director of the Division of Toxinology at the University of Cincinnati.

All desert flora and fauna have one guiding principle for survival, which is to conserve water. The ground surface of the desert has the highest temperature because of the direct effect of solar heat and wind. Therefore, during the hottest times of the day, most animals are either below the surface, in underground burrows, or above the surface in available vegetation, cacti, trees, or shrubs. Most animals forage from dusk until dawn, when temperatures are cooler. Some mammals, such as kangaroo rats, never drink, but obtain necessary water through plant seeds. Plants have evolved a number of survival adaptations to maintain water, including stomata which are closed during the day and crassulacean acid metabolism (CAM) photosynthesis, which allows for accumulation of carbon compounds at night via the dark reaction . Other adaptations include stem photosynthesis in plants without leaves, thick cuticles, water storage tissues, and widespread shallow root systems. They also have evolved a variety of defense mechanisms, such as production of toxic compounds that act as herbicides to others plants and the formation of needles, spines and thorns that dissuade browsing animals. Obviously humans are not ,able to evolve these physiological changes, but must rely on behavior, technology andother adaptations to mimic the methods used by indigenous desert dwellers.

All things being equal, preparation improves the likelihood of survival. However, things are never equal so luck is probably the most important factor. The controllable factors are mental and physical conditioning, clothing, survival kit adequacy and survival skills. These may allow one to survive even in the most extreme conditions.

Mental preparation is key to any survival situation. The “will to survive” has been shown to be the most important factor in the outcome of a number of situations. Knowledge of the terrain features, weather, animal and plant life, and potential hazards should all be studied prior to travel to a desert area. Not only does this increase one’s chances for survival, but enhances enjoyment of the desert environment. Practical experience in finding water and food, navigation, and constructing shelters is more valuable than reading about it. Time spent in attending a course on survival in general or desert survival in particular may be invaluable if one is later in a true survival situation.

Physical conditioning and acclimatization are as important for desert travel as for mountaineering. Desert travel is difficult under most circumstances. The terrain is rough and may include sand dunes, sharp loose rock, flash floods, steep grades, and hot surfaces. Leg conditioning helps prevent the ankle and knee injuries that can force a survival situation in a harsh climate. Acclimatization involves three well described physiological adaptations and usually requires 10 to 14 days in a hot environment. These adaptations are an increase in the volume of sweat and number of active sweat glands; a decrease in concentration of electrolytes in sweat, and sweating at a lower body temperature. These can be induced before arriving in a hot climate by the use of a sauna or vigorous exercise to raise body temperature.

Clothing selection for desert travel is somewhat different than for most other wilderness activities. The less exposed skin, the better. While cotton is not good for most cold, wet climates, it is useful in the desert. Light colored clothing reflects sunlight and lessens skin temperature. Ripstop cotton (cotton material with nylon threads latticed within it) is best because it resists rips that are common in the desert. It is light enough to allow heat to escape, does not creagte a clammy feeling in low humidity, and protects against some ultraviolet radiation exposure and blowing sand. If ripstop cotton is not available, then any tight weave cotton is adequate. Long sleeves and long pants are a must to protect againstspines, thorns, splinters and insects. More importantly, they protect against solar radiation that causes sunburn and increases body temperature, and trap more cool air next to the skin. Sweat that is trapped may decrease water loss via evaporation. Trousers can be tucked into the tops of socks to protect from insects; sleeves should be not be rolled up to minimize the risks of sunburn and heat gain. Gaiters can be worn to protect lower legs and the inside of footwear from sand, rocks, and dust. In a survival situation, puttees (wraps that extend from the tops of the shoes to the knees, either over trousers or bare legs, can be made from strips of cloth, elastic bandages, or stockings to protect the lower legs. They can be incorporated into the socks and wrapped to above the knees in a fashion similar to that for gaiters.

Because of the wide temperature swings, a pile jacket or sweater is necessary at night. Layering of clothing, just as for cold climates, is the best means of preserving body warmth. In a survival situation, any insulating material, such as seat cushions, newspapers or dry grass, can be used to insulate whatever clothing is available. Even though wind is more of a problem than rain, a Gore-Tex jacket is also recommended, especially for “cold” deserts. A wide brim hat or kepi (a cap with a cloth extending from the back protecting the neck) is necessary to protect the head, face, neck, and ears. In a survival situation, a head covering can be made from whatever material is at hand. A cotton cravat, bandanna, or handkerchief can be used to keep the head and neck cool by soaking the material in water (if plenty of water is available; do not use precious drinking water) and then placing it on the head followed by a hat, or wrapping around the neck and shoulders under a shirt. Commercially produced neck wraps (Cooldanna, Climatech, Stacool) and vests that contain crystals that can be soaked in water and then become cool through a chemical reaction are also available, but probably do not add much in the way of total body cooling in extreme environments The cravat can also be used during dust storms to protect the nose and mouth. It can also be used as a towel and to absorb moisture from plants when obtaining water.

High (6 inches) top boots composed of leather or synthetic materials are necessary to prevent sand, rocks, burrs from entering the boots, support the ankles on rough terrain, insulate the feet from hot surfaces, and prevent the boots being pulled off in soft ground. Boots should be well broken-in prior to hiking. Military issue boots with metal spike protection can become extremely hot in desert conditions and should be avoided. Running shoes do not insulate the feet well and may become extremely hot.

Socks should not be cotton, because of the risk of blisters and lack of wicking and insulation. Polypropylene or a combination of polypropylene and wool is the best for socks because of less friction and thicker material. Foot care is extremely important, especially in a survival situation when walking is the only means of transportation. Feet should be inspected for blisters, foreign bodies, and abrasions on a regular basis while hiking. Socks should be changed frequently, at least twice a day, to allow them to dry out and to remove accumulated dust and sand. Leather gloves are very desirable to protect hands from hot objects, plant spines, thorns and splinters, insects, and blisters.

Abrasions and lacerations to the hands can quickly become infected in conditions where hand washing is difficult. Eye protection becomes very important in the desert, especially when traveling. Solar radiation, both direct and reflected, can cause keratitis similar to snow blindness. More commonly, blowing sand, dust and insects may cause corneal abrasions and conjunctivitis. Contact lenses are difficult to manage in the dry, dusty environment. Tinted goggles are best, just as with mountaineering, but glacier glasses or standard sunglasses can be used. Duct tape, adhesive bandages or other material can be used to fashion side shields for regular glasses to prevent sand and dust from entering through the sides. Insect head nets can be lifesaving, especially in African, Arabian and Australian deserts, where insects and insect borne diseases are a particular problem.

Tags: desert survival, desert, survival, wilderness medicine, outdoor medicine, healthline

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Primitive Skills And Crafts

Primitive Skills And Crafts is "An Outdoorsman's Guide to Shelters, Tools, Weapons, Tracking, Survival, and More" compiled by Richard and Linda Jamison. The book is published by Skyhorse Publishing, Inc. and carries a retail price of $12.95 U.S.

The contributors to the book are Turkka Aaltonen, a survivalist and director of the Finnish Survival Guild; Donald Fisher, a historian of aboriginal lifestyles; Paul Hellweg, a wilderness survival expert and master of flintknapping (shaping flint, as for an arrowhead); the Jamisons; Peg Mathewson, an anthropologist; Larry Olsen, an outdoor survivalist; Jim Riggs, a primitive skills trainer; Steve Watts, an aboriginal skills expert; Dave Wescott, a pioneer in primitive outdoor education; Tamara Wilder and Steve Edholm, experts in primitive living skills; Ernest Wilkinson, an expert on animal behavior and winter survival techniques; and Margaret Wilson, a wild plant expert.

The book is written in essay format, rather than as an encyclopedia, so the writing style and level of detail vary from chapter to chapter. I found the historical explanations, such as that about the southeaster Indian rivercane blowgun, to be fascinating. So, as one peruses this book, he or she learns about how to make and/or use blowguns; hunting and fishing techniques with various spears, seines, improvised lines, traps, and the like; how to make primitive process pottery; stone survival tools; the many uses of the yucca plant, such as cordage, basketry, weaving, sandals, bags, mats, fire starter, and food; how to make hide glue; traditional basketry materials; tracking skills; primitive cooking methods; whole-shoot willow baskets; juniper-bark berry baskets; the nutritional value of a primitive diet; how to fashion a fire piston; throwing sticks; pine needle basketry; and the Paiute deadfall animal trap, to name a few.

There is no wilderness medicine in this book, but still much to commend it. It seems like it would be fun to attempt many of the skills described, so when your schedule permits, you might try to recreated some of these techniques, not so much to save your life, but to understand how incredibly easy we have it today. In listening to lectures by survivalists, I have come to appreciate that they certainly have their preferences for techniques, and opinions about the likelihood that any particular method will meet with success. So, you might wish to get a second opinion before you count on anything in particular that you read in a survival book.

If you are interested in the outdoors, and particularly in survival and history, this book is a fun read.

Tags: Primitive Skills And Crafts, survival, shelters, wilderness medicine, outdoor medicine, healthline

Labels: Primitive Skills And Crafts, shelters, survival, tracking

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