Category Archives: education

If you don’t use it, you lose it

It’s a common perception that “book knowledge” does not give on the ability to perform skills. People can answer the questions correctly on a test, but not do the right thing in a real life scenario. For the practical component to be there, you must have some degree of hands-on education and experience. Most (if not all) wilderness medicine courses have a mixture of both lecture and practical stations because of this need. But how long does that knowledge stay with the learner?

Honestly, nobody seems to know. Skills degrade when they aren’t used, but does it happen in one day, a week, a month, or a year? To see how well students retained the information they received from wilderness first aid courses, the authors of this study took participants and measured their baseline (post course) knowledge, and then randomized them to be followed up at 4, 8, or 12 months for retesting. To measure knowledge, they were given a 25 question multiple choice exam. It doesn’t mention if the followup test was identical to the original, but lets hope it isn’t. The participants were also asked to rate their own self efficacy based on an 11 point Likert scale that ranged from “cannot perform this at all” to “can perform this with high certainty”. The designers of that scale must have been fans of Spinal Tap.

At their followup testing, the study participants were again given the exam and asked to rate themselves. Then, first aid skill was measured by observing them do 8 specific skills as part of a clinical scenario. Unfortunately, this skill measurement was not performed at baseline, so absolute decline in practical application cannot be determined. However, based on their data (not shown in the article), they determined that skills declined as the time delta widened. It’s a bit confounding though, as the 8 month group did worse than the 12 month group in some skills. Their exam scores also decreased as time went on, but not to the same degree.

Thus, ability to do well on repeat written examination does not magically give one the ability to manage an actual clinical scenario (but those people probably do better than someone who did poorly on the written exam). And, as it turns out, how well you think you’re going to do doesn’t mean you’ll have the practical skills needed either. Like tying knots, the more regularly you practice them, the better you’ll get. And the knot you should use in a rescue situation is the one you can tie the best, not necessarily the ideal one taught in a class. In that regard, it’s important to note that they specifically excluded anybody who did have further training in wilderness medicine since the first course.

The problem is this: How often do you have to refresh those skills? This article doesn’t answer that question, but it certainly points out that those practical skills erode to a higher degree in between training than test scores do.  Some of this is common sense. It’s easy to do well on a multiple guess test if you’ve had some passing familiarity with the material, as the answers often refresh your memory. Doing the same in a clinical scenario is much more difficult if you haven’t practiced it since the last course. None of this is necessarily groundbreaking, as other studies have shown similar time dependent degradation. Thus, anything that you need to be facile with, needs to be done more regularly than every two years.

An examination of wilderness first aid knowledge, self-efficacy, and skill retention.

Simulation on a budget

When you are teaching procedures, most educators prefer for the first couple of attempts to be simulations, and not on actual patients. But if you’re going to be teaching wilderness procedures, there are other factors in question. Do you use your standard, computerized, high fidelity simulation mannequin in the hospital and play “wilderness” sounds in the background? Or do you try to truck that heavy and expensive equipment out into the woods?

Neither of those options is ideal. Thankfully, a group at the University of Michigan has come up with another option that involves a tradeoff in fidelity of the mannequin but incorporates fidelity of the environment. They took 7 common procedures and made low-cost, low fidelity simulation models that are portable, so you can take them out in the field.  The best part about their option is the budget friendly nature of it.

The seven procedures for which they made models were: cricothyrotomy, needle decompression with tube thoracostomy, lateral canthotomy, epistaxis control, pelvic binder, sucking chest wound management, and femur fracture. For the scenario, they use an actual person moulaged as the patient, then ask what procedure needed to be performed. Procedures were then performed on the models.  They made sure and used supplies that could be obtained easily at stores nearby, rather than having to call Laerdal® for replacement equipment. Because their designs are so ingenious, I’m going to go ahead and list the supplies used so it’s easier to emulate their models. I find it easier to use the ideas of people smarter than me than it is to come up with my own ideas. That being said, here are their models:

  • Cricothyrotomy: The actor had a history of facial trauma and makeup with blood in the oropharynx, was unable to speak, and had stridor. The model is nebulizer tubing (the part that is ribbed) that has a small hole already created but covered with athletic tape to mimic the cricothyroid membrane. Ketchup packets are then used on both sides to mimic vasculature, gauze as subcutaneous tisssue, and foam tape for skin.
  • Needle Decompression/Thoracostomy: The actor had a history of a fall with shortness of breath and right sided rib pain. Tracheal deviation and lack of breath sounds (hard to mimic) were given verbally. The model is an empty box with an inflated balloon inside. They used a wooden tangerine box, but a cardboard box would work fine. Pork ribs were placed over the balloon, and these were covered with thickened Jell-O for subcutaneous fat. Foam tape was used as skin.
  • Lateral Canthotomy: The actor was an elderly man who fell on his face while trail running. He has decreased vision and ecchymosis around his eye. He is on anticoagulants. On prompting, he has decreased vision, afferent pupillary defect, periorbital edema, and proptosis. The model is a ping pong ball on a base (they used a paper plate). The eyelids and skin were foam tape, and the crural ligament is athletic tape folded up to a 5mm width. The foam tape is stretched before attaching to athletic tape to allow it to come open when the crural ligament is cut.
  • Pelvic Binder: This and the sucking chest wound used the same actor. He had fallen from a tree and had chest and pelvis pain. He had diminished lower extremity pulses and was implied to have an unstable pelvis. The model was to use fabric wrapped around the pelvis and tightened with a stick used as a windlass. They specifically mention shirts or cravats for fabric, but I wouldn’t actually know where to obtain a cravat.
  • Sucking Chest Wound: The wound was created with makeup. They would dress it with whatever occlusive dressing they could mock-up, be it tape and gauze, a defibrillator pad, or an actual commercial device made for such purposes.
  • Femur Traction: The actor had fallen from a horse, and had right femur pain. The right leg is mocked up to be shorter than the left. They were to then apply a traction splint with 3 anchors, and if they didn’t have supplies, a telescoping ski rod, webbing, and a mug were used.
  • Epistaxis: The actor had experienced facial trauma and had a bloody nose. The model was a potato with a hole drilled through it. A 60cc syringe filled with red fluid was placed at one end, pushing this “blood” through the hole. They then packed it with whatever they had available. If they lacked supplies, a tampon sprayed with oxymetazoline was provided.

As you can see, these are easily reproducible, and you can even use the same supplies for multiple uses with only minimal changes (replace what is damaged). Only changes I would make are to put tape on the balloon you’re using to recreate tension pneumo, as this allows a steady rush of air without a sudden “pop” that isn’t as true to life. Honestly, I’ve never heard someone pop like a balloon when I put a needle in them, and I don’t know what I would do in a situation that they did. Also, make sure and take care going into bear country with a package or two of raw pork ribs.

Also, they used these stations in a MedWAR type race where they broke their students into groups and made them perform the tasks correctly, and also with the correct tools. This adds a bit of fun to the experience, as they have to combine orienteering, medicine, and physical activity into one event. It also adds a component of competition. The only hard part is getting enough proctors/moderators to man each station, as well as making sure students don’t actually get lost. On a final note, they did use testing and surveys before and after the scenarios to determine if students felt more comfortable with the procedures, and also if they had gained knowledge about the procedures. They found improvement in all, but statistically significant improvement in some. Small sample size certainly applies here. Still, it’s a great paper that gives easy instructions towards making an educational and enjoyable wilderness rotation for students.

How To Teach Emergency Procedural Skills in an Outdoor Environment Using Low-Fidelity Simulation