This past week, I had the opportunity to make a presentation on Wilderness EMS to an up and coming high school EMT class. The request was to give a brief overview of what Wilderness EMS is, and how it differs from traditional EMS.
My final product ended up giving a brief introduction to how we conceive of wilderness and wilderness medicine, and then I decided to dig into some of the simplest life threats encountered in the wilderness setting, and how they, they EMTs, could manage those life threats with just basic care and a little critical thinking. We finished the afternoon by learning a few basic skills such as how to improvise medical equipment in the field.
For my benefit and your enjoyment, here, then, is a written draft of my presentation.
I enjoy wilderness medicine for several reasons, some of which may stem from my time in scouts being outdoors, hiking, backpacking, etc, but there’s also a lot of freedom and autonomy in wilderness medicine. The "problem" with wilderness medicine is that it isn’t rigid. Protocols stop being absolute and start becoming “best judgment”.
Who knows the story of Hugh Glass? Who has seen the movie The Revenant?
Hugh had quite the life even before the bear incident. He was captured by pirates in the Gulf of Mexico and lived as a pirate for two years before managing to escape and swim to shore around modern Galveston Texas. Upon reaching land, he and another escapee were captured by Pawnee. The Pawnee murdered his companion and were said to be intent on doing the same for Glass, but he traded his way out of death and then lived with the Pawnee for a couple more years. He eventually left and traveled north to Missouri where he answered an ad for a hundred men to form a fur trapping company. He was shot in the leg during an Indian raid in 1822 while out on expedition. Finally, in 1823, while up the Missouri River, Hugh Glass was attacked, mauled, and very nearly killed by a grizzly bear in the wilderness of, what was then, the unorganized territory of the Louisiana Purchase.
He was rescued, but due to their extreme distance into the wilderness, and Hugh being all but dead, his trapping company elected not to carry him out and instead left two men to sit with him while he died to then bury his body.
After 5 days of not dying, those two men took all of his provisions including his rifle, dragged his body to the side of the river and left him there.
After a few more days, he finally woke up. He was able to drink from the river, eat some berries, and then get good and angry about being left for dead. He had one working arm and a broken leg. He was able to set the bone in his leg, wrapped himself in the bear skin that had been left as a shroud, and with one working arm and one working leg, began crawling.
He made it to the Cheyenne River where he was able to fashion a raft and float to Fort Kiowa on the Missouri. The trip took him six weeks. He survived on berries, roots, and the odd raw animal carcass. Luckily, maggots had taken up residence in his festering wounds and were able to keep it from turning gangrenous.
What is the "Wilderness" and What is "Wilderness Medicine?"
There is no true consensus on exactly what makes the wilderness the wilderness. It’s generally accepted to be a large area of land that’s been undisturbed by modern human development.
But how much development is the difference between disturbed and undisturbed?
Is Yosemite wilderness? It has roads.
What about along the Blue Ridge Parkway? Is that wilderness? Is it just “rural?”
With the definition of “wilderness” being somewhat fuzzy, the definition of “wilderness medicine” is also somewhat fuzzy. However, you can “rule of thumb” it as being medical care occurring at least 1-3 hours away from definitive care, and occurring in a resource restricted environment.
If I have a patient at the Caeser’s Head look-out that passed out from dehydration after hiking the trails, is that “wilderness medicine?” Probably not. Even if it may take me a while to get to the hospital, I still have road side access to the patient.
Now let’s say that same patient is down on the lower portion of the Rim of the Gap trail. Is that wilderness medicine? Absolutely.
Beyond just patient care, what other factors do I have to consider?
Patient Access
Patient Extrication
Walk vs Carry vs Helo
How do I get to the patient? That’s a little over 3 miles from the Jones Gap parking lot climbing up a rather gentle slope the entire time. That about 1.5 miles from the look-out going downhill the entire time. Then once I get to them, I have to take care of them until I get them to a hospital. However I’m also responsible for myself and my entire team. So how do we extricate the patient?
We’ll come back to these questions.
We use Wilderness as a catchall term for an entire discipline of medicine that focuses on delivering care in resource restricted environments. You may see such terms as RAW Medicine meaning Remote, Austere, and Wilderness Medicine, or RED Medicine meaning Rescue, Expedition, and Disaster Medicine. Tactical medicine also commonly falls into this discipline.
This discipline isn’t just emergency medicine, either. Being in austere conditions doesn’t necessarily limit your clinical ability. You may be the MEDPIC for wildland firefighters, and your job is handling sick call and keeping these firefighters in service instead of evacuating them to a clinic several hours away. That might involve you setting dislocations, or suturing in the field.
You could be MEDPIC on an oil rig.
You could be working a clinic in the African bush, doing spinal taps, or running vents in an ICU setting. The College of Remote and Offshore Medicine has paramedic degree programs for that: a Bachelor’s in Remote Paramedic Practice, and a Master’s in Austere Critical Care.
One of the interesting and most intriguing aspect of Wilderness Medicine for EMS personnel is the fluid nature of patient care. If you work for a large metropolitan service, where you have a hospital within an easy 10 minute drive wherever you are, you miss out on actually managing many of your patients. Patient care focuses less and less on patient stabilization and more on load-n-go.
If you work in a rural service, you’ll get to practice more actual patient management as you end up 30 minutes, 40 minutes away, even up to hours away from hospitals in the Midwest. The trade-off is, you have a lower call volume.
Wilderness medicine is much the same way in that you may have extended times of patient management, but it happens infrequently. However, when it does happen, you need to be prepared to problem solve, to think outside the box. You won’t have an ER doc close at hand to drop them off to when you run out of ideas.
In our setting, it can be pretty much guaranteed that you won’t have super critical patients. Because by the time you get to them, anyone without some sort of stability will likely be dead, and you’ve moved from rescue to recovery, and this is something that does happen from time to time.
By now you’ve likely come across the term, “the golden hour” as it relates to trauma patients specifically, but to other emergent patients in general. Basically that the care received in the first hour after injury, and getting to a trauma bay within an hour, are the largest predictors of patient outcome, after which, mortality increases significantly.
There’s no such thing as the “golden hour.” At least, evidence to support it is controversial. There’s a Golden Period, but you aren’t guaranteed to have an hour. If someone severs their femoral vein, they’ve got probably a golden minute. If someone breaks their arm, however, they could potentially go the rest of their lives without any life threatening complications. Hugh Glass went 6 weeks without medical care after a traumatic event known to be fatal in almost all instances prior to the advent of modern medicine.
Wilderness Emergencies are still time sensitive emergencies, and as such there’s an overwhelming urge for rescuers to rush to help the patient. However, wilderness medicine requires you to stop, evaluate, and think through the problem at hand. Don’t become part of the problem yourself.
First of all, how do I even get to my patient? Where do I get access from? Where do I egress to? You won’t always go in and come out the same way. Will I need equipment or technical expertise like rope access? What hazards may be present? Are there wild animals? Are we on the side of a mountain? Is there risk of falling debris?
Once I make it to them, now what do I do with them? Patient care should follow the MARCH algorithm. MARCH was developed in the military setting to address shortcomings in the typical A-B-C approach of Registry. They were finding that we were letting a lot of people bleed out while assessing their C-spine and airway.
M is for Massive Hemorrhage. If you don’t have any blood to pump transport the oxygen around, none of the airway stuff matters.
A is Airway. After controlling the major bleeding, now we move on to airway and C-spine.
R is Respirations. Are they fast, slow, shallow? Do they need decompression?
C is Circulation. Now that we’ve addressed the rest, we can now evaluate how well we’re perfusing the body. In a time crunch like a firefight, this would be: is there a pulse? Are they alerted?
H is hypo- or hyperthermia. This tends to be a pretty significant factor in mortality, and so it rates pretty highly on the list of treatable issues, and this is probably where we’ll spend most of our time.The rest of these, you’ll treat much like you’ll treat any such injury in the field, but H and H can be long-term management problems. Finally, you also have to figure out how you’re going to get out. Hike or Helicopter?
Alright, we've determined that our patient isn’t at risk of imminent death. Now what? Now you’re patient needs to be managed much like any other person in the same situation. Slow down, and start moving methodically.
Start evaluating other factors that may complicate patient care and extrication.
How much light is left?
What’s the weather like?
If anything presents too much risk to you, your team, or your patient, you should be prepared to sit on your patient until a better opportunity presents itself. That may mean setting up camp for the night. That may mean waiting out a storm.
Priorities of Survival
Your priorities of survival should be: shelter, fire, water, and food. This addresses the threats of environmental exposure, hypothermia, dehydration, and starvation.
Shelter
We need a barrier between us and the elements. This is a basic tenet of survival for the majority of life on the planet: look at the plethora of shells, nests, burrows. It doesn’t necessarily have to be elaborate. It can be as simple as the clothes you’re wearing. Clothing is perhaps your first line shelter. Rain gear protects against hypothermia from getting soaked. Winter gear keeps us warm against the cold air. The nomadic desert people have a specific style of dress designed to help keep sun off the skin and assist with thermos regulation by sweat evaporation.
What else do you have? What else do you need? Tents, tarps, a sleeping bag. All are good options for some sort of shelter/barrier.
Can you use the environment to your advantage? Caves, tree canopy, even just sitting on the leeward side of a hill could protect you from driving winds.
Fire
Fire is kind of odd in that it sits outside of the traditional heirarchy, and rubs shoulders with all of the other priorities. It is an integral part of your shelter, even if it’s a separate elements. It’s the reasons that hearths were central to many homes throughout history.
It’s a source of warmth.
It can dry out wet clothes/gear/people.
It can be used to boil water to make it potable
It can be used to cook food which aids in our ability to digest protein found in meat
It provides a boost to mental health. There’s sense of security in having a fire, and that serves to help boost the determination and drive of rescuers and patients. There’s something equally depressing about failing to start a fire.
Water
After oxygen, water is perhaps the most important substance required for our body’s ability to function.
The common conception is that the body can survive 3 days without water. What is not included in that is the profound cramping and weakness that renders a body ineffectual for hard labor.
It’s necessary to preserve life and “operational effectiveness” of personnel during a rescue operation. It’s equally necessary to use sterilized/decontaminated water to preserve bodily functions and prevent infection or poisoning.
On the flip side, electrolytes/salts are also vitally necessary and can be diluted from consumption of copious amounts of water, so oral rehydration should include electrolytes/salts.
Food
Food is a lower priority, however, it is still necessary to provide a source of calorie dense food for team members to maintain energy levels in events of high exertion (like search and rescue operations).
Heat Emergencies
Humans can tolerate excessive heat better than they can excessive cold. Our bodies are uniquely adapted to survival in hot environments.
Our sweat evaporates and as it does so, takes heat with it. Our blood also happens to be an excellent vehicle for moving heat from the internal organs to the surface of the skin so it can be radiated away. The acellular portion of our blood (the plasma) is roughly 91% water. Water has a high specific heat capacity, and if you were to take the temperature of your blood and compare it to the temperature of the surrounding tissue, you would find that the blood is a degree or two warmer than the tissue.
However, it can get overwhelmed. When it does, heat injury has three distinct stages starting with
In the acute stage, the body activates inflammatory mediators which is a fancy way of saying that your body will vasodilate in order to shunt more blood to the skin and radiate more heat.
In the intermediary stage, you can have derangement of the proteins in the blood
In late stage heat injury, you can expect multi-system organ failure
The most common heat related emergencies to experience in the field are:
Dehydration: which is just water lost without being replaced.
The early signs can be subtle like thirst, darkened urine, and dry membranes.
Moderate will see profoundly dry membranes, dry mouth, and a weak, rapid pulse
Severe dehydration will show shock and altered LOC
Heat Cramps
This is actually caused not by lack of water, but by too much “hypotonic” water. That is, you drink so much water that it dilutes your sodium. Your body uses sodium to help regulate cell action.
It’s usually resolved with rest, salty foods, and oral rehydration solutions. Only in rare, extreme cases would you give IV fluids for heat cramps.
Heat Syncope
Usually results from volume depletion and vasodilation: those two big things our body uses to eliminate heat.
It results in something called orthostatic hypotension which is a drop in blood pressure when moved to an upright position as the blood collects in the lower extremities.
Treatment is much the same
Get out of the sunlight
Lie down and rest
Oral rehydration
When the problems present in heat syncope start kicking into overdrive, you’ll start seeing heat exhaustion.
Typically profuse sweating
Fast heart rate
Weakness, fatigue, lightheadedness
They may or may not be hyperthermic
Treatment looks a lot like everything else thus far:
Get out of the sun
Lie down and rest
Aggressive Oral Rehydration with cold water
The goal is 1 – 2 liters over 2 – 4 hours
If the patient is hyperthermic (>104* temp), then start using active cooling measures
Heat Stroke
Heat stroke is the final stage before death. This is a true emergency. The old “red and dry” is false. They may still be sweating. They may not be. The big differentiating factor in heat stroke is altered loss on consciousness. They also classify this as occurring when body temp is >104. You may or may not be able to take a temp. If they’re coming out of a hot environment, they look overheated, and they’re altered, assume it’s heat stroke until proven otherwise.
Treatment of heat stroke includes everything we did for heat exhaustion, plus IV fluids, but the golden ticket to NOT cooking the brain is going to be active cooling. Cold water immersion is the preferred method, but it may not be available in most wilderness settings.
Cold Emergencies
Cold emergencies are a whole different animal. Remember, humans aren’t cold adapted. We have limited ability to combat hypothermia.
We can lose heat through radiation (how we usually give off most of our heat), conduction (when in contact with something like water submersion, or laying on a cold surface), convection (wind chill), and evaporation (even in a cold environment, dry air will leech moisture from your skin. That’s why your lips chap and you get nosebleeds in winter). Over long periods of time, your body (via the hypothalamus) will increase metabolic activity in the body in order to generate heat in order to combat mildly increased heat loss. In people who are slightly more cold adapted than us southerners, they have an innately higher metabolism.
However, when we’re talking about actual heat loss, we have one option: shivering. We can lose heat 4 different ways. We can generate it only one way. This is pretty effective when combined with shunting: using vasoconstriction to guide blood from the surface to the core. Our safety mechanism is susceptible to being hindered by wet clothing, and natural vasodilators like alcohol.
Both the shivering, and the vasoconstriction burn energy. The problem is, eventually you run out of energy reserves. When that happens, you stop shivering, and your vessels dilate releasing that warm core blood back to the surface. Since your perception of temperature is via nerves in the skin, you feel warm and even hot. This leads to the paradoxical undressing we see in some hypothermia events.
In mild hypothermia, you may have a mental status change: poor judgement, confusion. You’ll see the body amp everything up: heart rate, blood pressure, and respirations all increase. You can also start seeing a loss of fine motor skills. Now, bear in mind, this is MILD.
In Moderate hypothermia, you’ll see decreased mental status, slurred speech, muscle rigidity as you stop shivering, decreasing vital signs, and cardiac disrhythmias. That already sounds pretty bad, right.
In severe hypothermia: comatose, fixed and dilated pupils, non-detectable pulse, apnea, and bradycardia. Basically, you look dead. And you very nearly are if not reversed.
Improvised Field Care
Here’s one of the big things about wilderness EMS. You may not have a lot of gear. So you end up having to work with what you have. I carry a couple of SAM splints with me. If we’re on a trail, we may take a stokes basket on a big wheel. If you’re deep in the wilderness, or off trail, or this is a search and rescue, then you’ll only have access to what you have at hand. Being creative and improvising become necessary skills.
ALS vs BLS
Look back at what we’ve covered. How much of that was ALS and how much of that was BLS that an EMT, or really anyone can do? The vast majority of that was all BLS care, even for the critical conditions.
Heat stroke? Dunk them in cold water.
Hypothermia? Make a hypo wrap.
Heart dysrhythmia? I’m not toting a monitor into the woods with me. Palpate a pulse.
Dislocation? In true wilderness EMS, you may be reducing dislocations without any pain medicine and making them hike out.
Extrication vs Evacuation
Calling the helicopter in wilderness EMS isn’t like calling it on a 911 call. In the majority of the areas around here in the Appalachians, you won’t find a clearing large enough and with no hazards to land one. You’re going to have to hoist your patient out. Your helo will be a long time coming because you’re going to have to wait for the HART Team. Even MAMA, the largest private service helo, flying an EC145, doesn’t have a hoist. You’ll have to wait 4 hours for the HART Team to bring their Blackhawk up from Columbia. Think about that. You have a critical enough patient that you’re calling a helicopter… and you’ve got to manage that patient for 4 hours.
And what constitutes an evacuation emergency as opposed to something that can be resolved with good BLS treatment and time? You may have a hypothermia patient that can’t walk out. A good hypo wrap, shelter, and some high calorie intake, and your patient could be back on their feet.
This is part of why I shared Hugh Glass’s story. Think about it. The dude was mauled by a bear so much that the expedition left two guys to sit with him and dig his grave. When he came to alone, he had one functioning arm and one function leg, blood loss, maggots in his wounds… and the dude survived 6 weeks and a 200 mile trip through the absolute wilderness of what would become South Dakota, by himself, with no real medical treatment. The human body is remarkably resilient.
Scenario Conclusion
Let’s go back to our patient on the trail. You’re responding to a 911 call. The caller states that their hiking buddy passed out on the trail and feels to weak to go on. It’s October. The day is overcast with 20% chance of rain. A cold front is due to come through in twelve hours. The caller says that they both came with a single water bottle and no other provisions. They were dressed in shorts, short sleeve shirts.
What resources do you want?
How do you want to make access to the patient?
How do you want to egress the patient?
Once you make it to the patient, if you’re like me, you may feel like joining the patient. The patient looks pale, but is awake and talking to you. He said that he got really tired and passed out while hiking and didn’t feel well enough to stand up to hike out. Thoughts? (Heat syncope?)
Patient states that while they were waiting for you, he started having cramps real bad. Thoughts? (Heat cramps?)
However, while waiting for you, it had also begun raining, and now he’s shivering. His fine motor function looks decreased, and all of his vital signs are up. Now what are we thinking? (Mild hypothermia?)
Not only is it a cold part of the year, with a cold front coming in soon, and now it’s raining, but look at the geography of the trail. They’re on a trail that runs beside a creek which means they’re in the bottom of a draw. Cold air flows down and warm air rises. Mountain creeks tend to cool down the air around them and then pull cold air down the mountain with them. So now he’s sitting in a wind tunnel of cold air.
How do we tackle this goat rope now? Can we give him something for oral rehydration? Can we give him something like a space blanket to wrap up in, or make a hypowrap?
Just because I’m mean, not only is it overcast and raining, but it’s about 30 minutes til sundown, and your IC reports a thunderstorm is rolling in fast, and he thinks it’s too dangerous to be hiking/carrying out.
What are we going to do? What are our concerns? What are our priorities? Do we think we can manage this patient for potentially hours?
Shelter.
Overhead hazards like deadfalls.
Keeping team members safe and dry.
Fire.
Water close at hand in the creek.
Does the team have enough provisions for themselves AND patients?
Could you potentially wrap this patient up, give them oral rehydration fluids, and let them rest overnight. Then barring anything unforeseen happening, this patient should be ready to go by morning, we’ll just need to keep him warm.
Skills
The rest of the afternoon was spent doing some skills: improvised stretchers, improvised splints, C-spine in the field, and hypothermia wrap.
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