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Ask Stanford Med: Answers to your questions about wilderness medicine

Ask Stanford Med: Answers to your questions about wilderness medicine

Thanks for the great questions about health and safety in the wilderness. I enjoyed reading them and hope these responses will help you better prepare for your adventures this summer.

@sarahwhelchel asks: What’s the craziest situation you’ve ever had to deal with in the wilderness?

This is not “crazy,” but it was memorable. I was hiking near a lake when I was approached by a young boy out fishing with his friends. He came up to me in distress and it was quickly obvious that he had a problem. There was a big treble hook anchored in his nose, with one barbed prong embedded pretty far up inside a nostril and the other two hanging outside his nose. He was pretty agitated, so from a distance I asked him if it was “hurting real bad.” He shouted, “No.” Then he got closer he said, “It don’t hurt that much, but I sure would ‘preciate it if you could take off the worm.” I looked closer up his nose and there it was, wiggling around. I tried not to smile, but I couldn’t help it. I had one of his friends help me stabilize the hook to keep it from moving too much, and then I reached up with a tiny blade and scraped the crawler off the barb. The kid was a tough little fellow and let me push the point of the hook through his nose so that I could cut it off and extract the hook. Afterwards, I asked him to tell me the truth – what was the worst part? He was emphatic: it was the worm!

@rdicker asks: I pack all the basic first-aid stuff for hiking. What is the most common serious injury people don’t prepare for?

I can’t say for sure the most common serious injury for which people don’t prepare. But I can provide a list some things that are tragic because they could have been avoided with proper preventive measures. These include:

  • Drowning because a person wasn’t wearing a life jacket or didn’t have a personal flotation device
  • Being struck by lightning because a person failed to seek shelter during a thunderstorm
  • Suffering an attack by a wild animal because of intentionally approaching the creature
  • Falling over a cliff or waterfall after ignoring a posted warning sign
  • Sustaining a head injury because of failing to wear a helmet while rock climbing or mountain biking
  • Being bitten by a rattlesnake after trying to handle a venomous reptile
  • Suffering a serious burn after tripping into a campfire while intoxicated
  • Breaking a leg because the person didn’t bring a hiking pole to maintain balance on a rocky, uneven trail
  • Developing disabling blisters because boots were not properly broken in or were too tight


@smccaw asks: When it comes to black widow spider bites and children, what is the best approach for treating them in the wildness?

Fortunately, black widow spider bites are uncommon in true wilderness settings. They more commonly occur in urban or rural settings, such as when someone reaches into a shoe that is hiding a spider or sits down on a spider while using a latrine.

If a bite occurs, apply an ice pack to the bite for pain relief. Understand, however, that this might not be very effective and that it does not really affect absorption of the venom into the body. If possible, transport the victim to a medical facility immediately in anticipation of a worsening clinical situation. Once the victim is in the hospital, the doctor will have a number of therapies to choose from, including antihypertensive drugs for elevated blood pressure, pain medicine and, in very severe envenomation cases or special circumstances, antivenom.

If you are unable to reach a hospital within a few hours and the victim is suffering severe muscle spasms, you may administer an oral dose of diazepam (Valium), if you have it on hand. The starting dose for an adult who does not regularly take the drug is 5 mg, which can be augmented in 2.5 mg increments every 30 minutes up to a total dose of 10 mg, so long as the victim remains alert and is capable of normal, purposeful swallowing. The starting dose for a child age 2 to 5 years is 0.5 mg; for a child age 6 to 12 years the starting dose is 2 mg. The total dose for a child should not exceed 5 mg, and never leave a sedated child unattended.

David asks: I understand it is a big year for ticks with Lyme disease. How do you remove or treat the tick? Also, how do you determine if you’ve been infected and treat the infection?

The proper way to remove an embedded tick is to grasp it close to its mouthparts with, preferably, tweezers or fingernails that are covered with a thin glove, cloth or tissue paper to prevent contact with infectious tick fluids. Then, pull it straight out with a slow and steady motion. Another way to remove a tick is with a grooved or V-shaped device designed to slide between the tick and the skin to trap the tick and allow it to be pulled from the skin.

Do not twist the tick. Do not touch the tick with a hot object, such as an extinguished match head. And, don’t cover it with mineral oil, alcohol, kerosene, camp stove fuel or Vaseline. Such remedies might cause the tick to struggle and regurgitate infectious fluid into the bite site. Viscous lidocaine 2 percent applied to a tick for 5 minutes will cause it to detach its grip, but it is not known if the tick regurgitates. If a tick head is buried in the skin, you can apply permethrin (Permanone insect repellent) using a cotton swab to the upper and lower body surfaces of the tick. After 10 to 15 minutes, the tick will relax and you will be able to pull it free. After the tick is removed, carefully inspect the skin for remaining head parts and gently scrape them away. Wash the bite site with soap and water, or with an antiseptic. Then wash your hands.

The period of time that a tick must be attached before it transmits the infectious spirochete that causes Lyme disease is generally considered to be 48 hours, but this is not absolute. Lyme disease infection is often first noticed as a distinctive skin lesion (“erythema migrans”), but this may not be present. Within days to weeks of infecting a human, the infectious organisms spread through the bloodstream and lymphatic system to affect other organs. Therefore, appearing just before, or coincident with, the skin rash(es) are flu-like symptoms that include muscle aching, particularly of the calves, thighs and back. Additional symptoms include: stiff neck, fatigue, low-grade fever, chills, nausea, swollen lymph glands, abdominal pain and irritated eyes.

Most of the symptoms disappear within 2 to 3 weeks, but fatigue and muscle aching may last for months. Lyme disease when recognized in its early stage can be treated with antibiotics.

Elizabeth asks: I understand the protocol in the event of a rattlesnake bite [is] to immobilize the area, avoid rapid circulation and transport immediately. What happens when those goals are in conflict with one another? Assuming the victim cannot be carried by companions because of distance or terrain, is it better to dispatch the fastest person to bring help back?

No popularly described first aid therapies, such as incision and suction, venom “extractor” devices, application of ice packs, whiskey ingestion or tourniquets, have ever been proven to be effective in treating a rattlesnake bite. The only truly effective therapy to counteract the effects of venom therapy is administration of antivenom. For this reason, it is best to begin heading back to civilization as soon as possible.

If the bite victim is capable of walking, with or without assistance, then that is what should happen. The theoretical risk of worsening the situation by walking is outweighed by the need to bring the victim to a medical facility where antivenom can be properly administered. The exception would be if you’re in a remote location that is reachable by mechanized transport, such as a vehicle or helicopter, and the victim is incapable of self-extrication, with or without assistance. If help is needed to speed up evacuation and that help is expected to arrive faster than everyone can walk out, then it’s OK to stay put, dispatch the fastest person to get help and wait for reinforcements – assuming that there is adequate shelter with protection from the elements, food, water and so forth.

Boone asks: Recently, I’ve noticed that when I am hiking a longer distance (eight or more miles), I have a lot of swelling in my hands and forearms. Do you know what might cause this? Is there a way to reduce the swelling in the hands, fingers and forearms when hiking?

The most common cause of swelling in the hands during hiking, or any other form of prolonged exercise, is simple: gravity causes pooling of fluid in the soft tissues. When the arms are held with the hands hanging down, some combination of blood in the veins, lymph fluid in the lymphatic system and fluid in the soft tissues migrates to the dependent area and causes swelling. The amount of swelling varies from person to person, is harmless, and isn’t a cause for concern.

Once the swelling occurs, it will resolve when the arms attain a “neutral” (at heart level) or elevated (above the level of the heart) position long enough for the fluid to migrate out of the area. This most commonly occurs during sleep. A serious cause of swelling in the hands would be high or low sodium level in the bloodstream, either of which can cause fluid retention. So, proper hydration is important.

If you’re a person whose hands swell with exercise, then avoid wearing constrictive garments, particularly at the armpits or wrists. You may also want to remove constrictive jewelry, loosen backpack straps, shift the weight-bearing to the belt strap or switch to a fanny pack. Contracting your hand muscles by squeezing a ball or gripping hiking poles while walking may help. Alternatively, you could take breaks and swing the arms in wide circles to promote circulation and fluid redistribution.

An answer to any question submitted as part of this feature is meant to offer medical information, not medical advice. These answers are not a basis for any action or inaction, and they’re also not meant to replace the evaluation and determination of your doctor, who will address your specific medical needs and can make a diagnosis and give you the appropriate care.

Previously: Ask Stanford Med: Chief of Emergency Medicine taking questions on wilderness medicine
Photo by Gunnar Hildonen

2 Responses to “ Ask Stanford Med: Answers to your questions about wilderness medicine ”

  1. Griff Harsh Says:

    What is the pathophysiology of altitude sickness (hypoxia –> hypervintilation –> decreased pCO2 –> altered pH of blood / CSF ??) and how do diamox, NSAIDs and hydration alter this?

  2. Paul Auerbach, MD Says:

    The pathophysiology of high-altitude illness has been described for each of high-altitude pulmonary edema (fluid in the lungs), high-altitude cerebral edema (fluid in the brain), acute mountain sickness (which may be premonitory to HACE in particular), and other high-altitude-related medical problems. Probably the best way to briefly answer this question is to address the acclimatization process, which increases oxygen delivery to cells and perhaps allows them to better withstand low concentrations of oxygen. This may have a genetic factor(s), such as the “hypoxia-inducible factor (HIF),” which in some way affects the expression of hundreds of genes. The physiological changes observed with acclimatization to high altitude include increased ventilation, circulation (elevated heart rate), more effective transfer of oxygen from the bloodstream to the tissues, increased red blood cell production, and so forth. Let’s take each of your examples and briefly hypothesize a beneficial effect. Acetazolamide (Diamox) is a respiratory stimulant, which supports breathing during sleep and helps smooth out breathing patterns that are essential to maintain oxygenation. It also promotes a bicarbonate diuresis that mimics and might hasten the natural acclimatization process. NSAIDs, typically ibuprofen, may be beneficial due to its anti-inflammatory properties, but we need to learn more about effectiveness and physiological effects related, in particular, to acute mountain sickness. Hydration seems to be beneficial, but the evidence for this comes mostly from empirical observations that dehyration is detrimental. It is important to note that overhydration can be dangerous, so the goal is normal hydration.

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