Wilderness Medicine: High-Risk vs Low-Risk Evacuations

One of the most important skills taught in a wilderness medicine course is how to determine if an accident requires a high-risk or low-risk evacuation. If someone gets injured or sick on trip, you need to assess how urgently they need medical treatment. Move too slowly and the injured / sick person may deteriorate to the point where permanent damage (or worse) sets in. But move too quickly, and you put your team’s and the rescuers’ lives at risk.

In this post I’ll describe how we decide to do a high- or low-risk evacuation.

Note: This post does not replace the training you receive in a wilderness medicine course. I recommend taking a course before spending prolonged time outside.

Interested in a course? Find all available courses on the Wilderness Medicine Association website.

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Is an evacuation necessary?

When an accident occurs, our first thought should be: Is an evacuation necessary? The question we’re really asking is “Can I fix this in the wilderness?” Minor accidents can usually be resolved in the wilderness. This includes scrapes, cuts and minor burns that are easy to treat. It also includes temporary illness like a headache or a single episode of vomiting or diarrhea. You do the necessary treatment and the problem resolves itself.

This is also where your training plays a really important role. If someone on your trip cuts their leg on trip, and you know how to correctly wash and dress the wound, that person may be able to stay on the trip. If you don’t know how and there’s a risk for additional bleeding or infection, the person would need to be evacuated.

Other examples could include a twisted ankle, mild hypothermia or heat exhaustion. Each of these have a treatment and, if applied correctly, can get the patient functioning and back to the trip. It may, however, require modifying your trip (such as taking an extra rest day to monitor the patient’s recovery).

The key wording here is “treatment applied correctly” – this is why wilderness medicine training is so valuable; you need to know what treatment to apply and how to apply it correctly.

If you can fix something in the wilderness, an evacuation is not necessary. If you can’t fix something in the wilderness, an evacuation is necessary.

High-risk vs Low-risk Evacuations

When we think “evacuation” we typically imagine helicopters swooping in, but that is rarely what happens.  The method of evacuation depends on whether a high-risk or a low-risk evacuation is required.

One misconception when you talk about high- and low-risk evacuations is that we are referring to the patient being in a high or low risk situation. This is not the case. The risk we are talking about pertains to the rescuers. What we’re really asking ourselves “Is this emergency urgent enough that we should put the rescuers at risk?”

In other words, “high-risk” means those performing the rescue are at a high risk themselves. Each year, rescuers are injured or killed while performing rescues, so we only want to put them in risk if the patient has severe, potentially fatal injuries. For example, if someone has deadly bleeding or has stopped breathing, we need help immediately. A high risk evacuation is appropriate.

“Low-risk” evacuations are not as time sensitive so they can be performed over more time. For example, rather than having a helicopter or float plane meet you on the river, your group might paddle the patient to a portage trail that connects to an access road, where an ambulance could meet you. A stable, fractured ankle, while painful and something you can’t fix in the wilderness, usually isn’t life threatening.

How do you know if a high risk evacuation is required?

Here is the simple way to know if an emergency requires a high risk evacuation: if any of the ABC’s are in jeopardy, a fast evacuation is needed. The ABC’s stand for: A – Airways  | B – Breathing | C – Circulation | These three systems keep the body alive, so anything threatening them is an emergency and typically requires a high-risk evacuation. Chest wounds, heart attacks, anaphylactic shock, broken femur, drowning, severe hypothermia – these are just a few examples of situations that could be a high-risk evacuation.

It’s also important to remember that the fastest evacuation isn’t necessarily the most complex or high-risk; you need to consider your surroundings and the specific context of the emergency you’re in.

Additional Evacuation Examples

Anaphylactic shock

Can you fix it in the wilderness? While Epi-Pens, anti-histamines and prednisone are all drugs that contribute to the treatment anaphylactic shock, they did not fix the problem. The patient needs a hospital. Evacuation is necessary.

Is it a high-risk or a low-risk evacuation? Both breathing and circulation are being severely impaired; a fast evacuation is imperative. Choose the method that is the fastest and more reliable way to get the patient to the hospital.

Large cut on the thigh from a fall on rock

Can you fix it in the wilderness? If applying direct pressure stopped the bleeding and you could effectively clean the wound, you could fix this in the field. It would require ongoing monitoring (maintaining a clean dressing, ensuring there are no signs of infection).

Wilderness Medicine is important!

Hopefully this has highlighted the complex nature of medical emergencies in remote environments and has inspired you to look into getting some kind of training before setting off on your next adventure.

I can’t stress enough how important wilderness medicine training is when you’re outside. If you have any questions or need help finding the best course for you, please reach out! You can also learn more by reading the following related posts.

• How to build your own Wilderness First Aid Kit
• Wilderness First Responder: A glimpse into a backcountry medicine course in Costa Rica
• Which Wilderness Medicine Course should you take?

Disclaimer: I am not an instructor for wilderness medicine courses. I have taken a great deal of them and find them incredibly valuable. This post is not a substitute for training, but intended to demonstrate the value in getting wilderness medicine training.

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