Category Archives: Macgyvering

So maybe you can use that for a wilderness airway

We’re going to have to talk about the improvised wilderness airway. Caveat: this post is not exactly evidence based. It’s literally an anecdote. But an amazingly good and peer-reviewed anecdote at that. And there is a smattering of evidence thrown in at the end. Typical wilderness airway tool

The case report starts like this: Three firefighters were climbing as part of a team in California when they saw a man falling ~1500ft down a rocky slope. They descended to offer help, and when they got there they removed his helmet, checked ABCs, and maintained his C-spine. Neurologically he was unresponsive. Two emergency doctors with a separate climbing team arrived 15 minutes later. By this time his respirations were irregular and they noted significant facial trauma. Due to gurgling respirations, they decided to perform a cricothyrotomy.

All the physicians had for supplies were climbing equipment and a small first aid kid. They used a pocket knife to make the incision (vertical first, then horizontal), and tubing from a hydration pack as a makeshift ETT. Suture from the first aid kit was used to secure the tube. Since respirations were spontaneous, they did not perform positive pressure ventilations initually.

His pelvis was bound with a pair of pants, and extra clothes were used to prevent hypothermia. After 30 minutes though, his respirations became irregular again. Blood was noted in the tube, so the team decided to create a makeshift positive pressure bag using the rest of the hydration pack. One of the team would blow into hydration bladder to inflate it, and close it off using pliers as a valve of sorts. They would then deliver breaths by squeezing the bladder, similar to commercial products. They used this for another 30 minutes successfully.

Helicopter transport eventually was able to evacuate the man, and it turns out that a 6.5 ETT adapter fit into the makeshift tube easily. A bougie did confirm airway placement, and etCO2 readings were monitored. Unfortunately the patient went into V fib, got ROSC, then went into it again shortly after. The patient never regained pulses after that, and was pronounced dead prior to landing at the hospital.

The most important point of this case report isn’t the cool factor of Macgyvering other equipment into functional airway tools. It’s making the hard decision to perform the cric in the first place. Making that call, even in a low resource setting, is critical. Sadly this patient didn’t survive the injury, but it wasn’t due to lack of an airway. The fact that these physicians were able to also devise and then produce something that gives some form of PEEP is icing on the cake. However, it would be nice if someone took this device and measured what kind of pressures they could obtain with it.

And remember, if you’re going to perform a makeshift cricothyrotomy as your wilderness airway, make sure to use something of proper diameter. Ballpoint pens have too much resistance, but sports bottle and hydration bladder straws will work in a pinch.

Improvised Cricothyrotomy on a Mountain Using Hiking Gear

Is there anything a SAM splint can’t do?

Deciding what to carry in your medical kit on an expedition is hard. You don’t want to leave anything out, but you can’t carry an entire hospital on your back. I mean, the wheels on the slit lamp really suck at crossing rough terrain. So you have to decide what goes and what doesn’t. Thus the reason for much of the improvisation inherent in wilderness medicine. An item that only does one job had better be the only item that can do that job, or it is extra weight.

C collars are one of those items. Now, ignoring the fact that many of them aren’t good at their job to begin with, they really aren’t good for much else. Sure, you could maybe improvise a pressure dressing out of it, but what else are you going to do? And while some of them do lay flat, they’re still pretty long and take up space that could be used for something else.

Enter the SAM splint®*. Waterproof, moldable, and able to be cut to size, it can be used pretty much anywhere on the body. And everyone has seen the picture of one being used to immobilize the cervical spine. But does it work well in that role?

Improvised C Collar in Auckland

These authors put it to the test against a Philadelphia collar using 13 EM resident “volunteers”. I’m sure they were paid well for their time. Using a goniometer they measured maximal extension, rotation, and lateral flexion. They found that no statistically significant difference in any one measurement, but looking at the results the SAM does appear to allow slightly more rotation and extension, while doing a better job of limiting lateral flexion. This likely is due to the bulkiness of the SAM laterally.

While the method of measuring falls short of a radiographic gold standards, and the number of subjects is low (but powered to an 11° difference per the authors), it looks like the SAM splint, in fact, is just as good as a Philly collar at immobilizing the C spine. I am OK with it in an awake patient, but would add more reinforcement to an unconscious patient.

Comparison of a SAM Splint-Molded Cervical Collar with a Philadelphia Cervical Collar

*I’m using SAM splint to cover all the moldable splints out there, similar to how Xerox is used to cover all photocopiers. I do not receive any money from SAM Medical Products® for using their name here. You are welcome to use other splints, but this article only used the SAM.

A novel prevention for acute mountain sickness

Every now and then someone thinks outside the box and causes a change in medical care. This is one of those things. I was alerted to this letter to the editor by the always excellent R&R in the Fast Lane, and when I went to the original source, I was astounded. Not many people would consider inducing pneumoperitoneum as a treatment for anything.

The letter is published almost like an abstract, and does a good job of explaining the problems that people run into when they have to go to high altitudes on short notice, such as rescuers of natural disaster victims like the one recently experienced in Nepal. And while I agree with them that there may not be time for people to go through any of the the classically used acclimation methods, I’m not sure that we should extrapolate the data that says injecting 20mL/kg of oxygen under skin can reduce the symptoms of AMS. Notwithstanding the fact that I cannot get that article to even see what they were talking about, this letter at least mentions that subcutaneous injection wouldn’t be able to hold enough oxygen. How does it hold 20mL/kg to begin with?

So of course the next logical step for a viable container is the peritoneum. They even go to great steps to mention how to create said pneumoperitoneum, and how to make sure that you don’t create too much pressure in the abdominal cavity. What they don’t explain is how there’s a place that is too remote to have oxygen tanks, but is able to use trocars to inject oxygen into the peritoneum AND be able to measure the pressure of said abdominal cavity. So, while this may in theory work, there are easier, much less invasive methods of carrying extra oxygen up the mountain. Why take it out of the bottle to begin with?

There’s a fair amount of theory about the benefits of this, including increased airway resistance, and decrease in free radicals. I don’t buy it, because you get more free radicals with hyperoxemia, which is what they’re advocating to begin with. And I’m not sure increased airway resistance would be all the beneficial either. Not to mention the obvious problem you have with expansion of gas as you decrease atmospheric pressure. I’m sure people would love the feeling of their abdomen doubling in size. So while they end with:

In summary, artificial pneumoperitoneum should be considered for AMS prevention in persons who must ascend to high altitude and begin work without rest and acclimation.

I say we shouldn’t consider this.

An artificial pneumoperitoneum created by injection of oxygen may prevent acute mountain sickness.

Necessity is the mother of tourniquet invention

A lot of wilderness medicine teaching is geared towards bringing the right tools for the circumstances, but sometimes you end up in a situation where you don’t have the best tool for the job. Thus,  quite a bit of preparing for austere environments is making improvised devices out of whatever is lying around.

This article discusses one of those macgyvered lifesaving tools. While there are many commercially available tourniquets out there, there are still times when you have to create one out of something else. As the article points out, you might simply run out of tourniquets at a mass casualty incident. When the situation arises that you have to create a tourniquet, what items should you use to make one?

The authors chose to test the band and windlass design. They mention that this was based on a paucity of non-military literature about various improvised tourniquets. The band was always cotton cloth folded into shape, and they tested 3 items common to the urban environment as windlasses. While pencils, chopsticks, and popsicle sticks might not exist in the wilderness, they’re a reasonable idea for testing. It’s not like you can ensure quality control with broken twigs.

Using a computerized above-the-knee amputation simulator, they then attempted to stop bleeding using the improvised tourniquet and one of the potential windlasses. If 1 pencil, popsicle stick, or chopstick was insufficient to stop bleeding (or broke), the test would be repeated with 2, 3, or 4 until 100% effectiveness was reached.

Granted, this study only looked at occluding arterial flow instead of venous, and had a very narrow scope of windlasses. In the end, the take-home message is as follows:

  • Popsicle sticks suck as windlasses, and you shouldn’t use them. They often broke on the first turn.
  • Pencils are better, but still pretty terrible.
  • Strangely enough, chopsticks work best of those tested.
  • 2, or better yet 3, is always better than 1 when it comes to windlasses
  • Maybe use something other than flimsy wood objects when you make an improvised windlass, such as plastic or metal
  • Use a commercial device if you can find one

Which Improvised Tourniquet Windlasses Work Well and Which Ones Won’t?