Cricothyrotomy on HEMS
/Highlighted Article High, K., Brywczynski J., Han J. Cricothyrotomy in Helicopter Emergency Medical Service Transport. Air Medical Journal , Volume 37 , Issue 1 , 51 – 53
Introduction
This was a retrospective chart review of air medical patient records from an EMR. It was done by Vanderbilt LifeFlight, which consists of 6 rotor wing aircraft and 1 fixed wing. Medical crews are either RN/RN or RN/medic. They perform approximately 2000-2500 transports a year.
For this study, they analyzed all of the cricothyrotomies that were performed by their crews over a 113-month period. They excluded patients under the age of 13. They use relatively standard criteria for cricothyrotomy and also have other advanced airway skills, including RSi. The staff practice the skill in both animal and cadaver labs on a biannual basis, with a minimum of at least 1 tissue procedure per year each.
They utilize two different methods for cricothyrotomy. The first being a percutaneous approach designed by Melker, utilizing a Seldinger technique over a wire. The second is an open/surgical method, in essence the scalpel-finger-bougie method. The decision as to which to use is left to the provider performing the procedure.
Results
Of their 22,434 transports during this period, 13 patients underwent cricothyrotomy, approximately 0.057%. 58% of these were performed on patients from scene flights and 42% on interhospital transfers. Males comprised 75% of the group and trauma patients were 77%. Mean estimated patient weight as 97 kilograms and mean initial GCS was 5. All 13 patients had attempted endotracheal intubation first. 6 of the attempts were percutaneous, and 7 were surgical. One patient required 2 surgical attempts, and 1 patient required a surgical rescue after a percutaneous attempt failure. All patients were ultimately successfully ventilated. 42% of the patients survived to 24 hours post-procedure.
Limitations
Sample size was relatively small, which is to be expected with this rare procedure. It’s also a retrospective review and it is difficult to account for various biases as to why one method was chosen over another.
Discussion
Other studies generally place the rate and success of prehospital air medical cricothyrotomy similarly to the results of this study. Over the last 1-2 decades, multiple advances have been made in prehospital airway management, most notably the development and widespread use of EGDs as well as expansion of training and use of paralytics in the prehospital setting to optimize intubation. It is expected that the frequency of cricothyrotomy will continue to fall with further advances in equipment and training in the future. However, there will continue to be a need for this potential life-saving procedure.
Learning Points
Overall, I think this article provides further support of the importance of cricothyrotomy skills and maintenance in our environment. I think the biggest takeaway for me (as well as the authors) was the potential weakness of having two different methods of cricothyrotomy. This requires providers to learn and maintain both, and also requires additional decision-making in high-stress, time-critical situations. In addition, each provider also has to learn how to assist the other provider in performing either of the procedures. Many experts advocate for the superiority of the surgical (scalpel-finger-bougie) method of cricothyrotomy over the percutaneous approach, and I would have to agree. In this very small study this method did seem more effective, as well. It should always be a goal to look for the most reproducible and effective method of performing a procedure, and then train that exact way as much as possible. Not only will this reduce cognitive load during these situations, it will also lead to a higher level of proficiency in this procedure for all crew members.
As Bruce Lee says – “I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times.”
Authorship
Andrew Cathers, MD - Dr. Cathers is an Emergency Medicine Physician as well as Flight Physician, and Assistant Medical Director of University of Wisconsin Med Flight with a focus on Education and Training in their Program. He is kind enough to share recaps of recently published HEMS literature which should be posted quarterly here on TamingtheSRU
