Cricothyroidotomy – considerations for teaching & simulation

Earlier this week I posted about the integration of a cric task-trainer at ARHT. I’ve decided to follow this up with some general evidence about cricothyroidotomy training.

The data regarding technique selection for cricothyroidotomy exists primarily in the context of simulation. It would be impossible to run a trial to compare techniques in real patients given the rarity of the scenario. In general, there are two types of techniques: 1) open or surgical cricothyroidotomy 2) percutaneous or needle cricothyroidotomy. I tend to favor an open technique (and maybe with a bougie)  given the simplicity but there is some evidence to support the needle method. There is a nice  Below is a brief outline of some evidence-based considerations for anyone involved in training clinicians for cric performance.

Needle vs. Open

  • Randomized trial of emergency physicians performing surgical and percutaneous cricothyroidotomy on cadavers. Time to first ventilation was significantly longer using the surgical technique (108 seconds vs. 136 seconds) while there were significantly more injuries to surrounding structures using the open technique (6 thyroid vessel injuries vs. none)
  • Authors concluded results tend to favor percutaneous technique
  • I’m quite surprised that time was shorter with the percutaneous technique – interesting result!

Alternative techniques

Time to Completion 

  • Highly dependent on when the timer starts but regardless everyone agrees time is important! And less is more!
  • 40 seconds was achievable in one study – time to skin palpation to first ventilation when all equipment was laid out
  • 95 seconds (mean) was recorded in another study as time from first grasping cric equipment to first ventilation

Number of times to achieve competence

  • Debatable whether experience = competence
  • Performance times plateau after 4 attempts (using a manikin)
  • Very little evidence to support number of times needed especially since all evidence is manikins or cadavers

Room for improvement as an inter-disciplinary approach

  • Several studies show that often it’s the surgeon performing cricothyroidotomies in emergent settings (article 1, article 2
  • This has important training implications – we should be training as a trauma team and incorporating the trauma team during in-situ simulation
  • EM teachers & educators must also be aware of this issue and work with surgeons so that they understand cricothyroidotomy is completely within the scope of practice for EM physicians (or anyone who performs RSI)

Some High Quality Learning (FOAMed)

Cricothyroidotomy training for the pre-hospital setting

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Newest addition to the ARHT simulation centre. Cricothyroidotomy task trainers built from old manikins. Rolled them out successfully last week with our paramedics using them for the first training session.

One of my medical education interests is looking at how we train and practice rarely performed procedures. For these situations, simulation offers an excellent method of training. The challenge, however, is recreating the fidelity of such situations since many rarely performed procedures are quite invasive.  Often we’ll start the training with a task-trainer like model and then progress to a full size manikin. Task-trainers are simulation models specifically designed for one type of procedure. 

In emergency and pre-hospital medicine, the cricothyroidotomy is among the most invasive, time critical yet rarely performed procedures. In addition to the potential technical challenges of this procedure, the decision to perform a cric might be even more difficult.  Identifying a “can’t intubate, can’t ventilate” scenario and then to “pull the trigger” may be one of the hardest cognitive leaps we face in resuscitation.  For example, last week, in the  Auckland emergency department we ran an in-situ simulation scenario for the registrars that required the performance of a cricothyroidotomy. The goal of the simulation was only to perform a cric…in fact, we even gave the registrar team a heads up that the patient would required a cric. Amazingly while we only used a task trainer that didn’t even allow for intubation, the trainees still tried to proceed with intubation. There was considerable reluctance to finally acknowledge that it was a “can’t intubate, can’t ventilate” situation.  I don’t think we train enough to practice taking that cognitive leap to the final step in the failed airway algorithm. Even this short little scenario provided evidence that such scenarios require practice and should be simulated.

This past week at the base we rolled out our cricothyroidotomy task trainers. We constructed our trainers based on a model created by Agnes Ryzynski & Dr. Jordan Tarshis at Sunnybrook Health Sciences Centre. They described the creation of such task trainers using old/broken manikin heads and some innovation using easily found products within the hospital. The value of such a trainer extends beyond its simplicity as it also  maintains good fidelity, it costs less than $30 to make and it recycles old manikin heads! 
Such a trainer might supplement an even lower fidelity construction depending on the setting. At the ARHT, our go-to method for cricothyroidotomy is a bougie-assisted technique which is described in this article and video. We’ve selected this technique based on simplicity in the field and relatively minimal equipment required. But there’s good debate out there whether these should be performed using the needle or surgical approach. Scott Orman (ED physician and blog author for aucklandhems.com) wrote about the topic last week with some great links.

You can see from the pictures, that the paramedics have set up on the left side of the patient. We were trying out different approaches and set ups to find out what works best. Personally, I prefer the right side of the patient. In our setting within the helicopter  we only have access to the patient’s right side. As a result, there may be some benefit to be on the right side. The ergonomics of such a high stakes procedure are probably understated so training in the same way that you’ll perform the procedure is essential. I acknowledge that you might need to be a bit flexible regarding setup but in general, the airway team should be well prepared and anticipate where equipment and personnel will be placed.

Here’s a few more pictures of our training day.

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Next post will have a bit more about the evidence base around cric performance.