Perhaps most alarming, a wide variety of surgical airway kits are on the market, each with nuances in approach and technique, and each equally likely to find its way into your difficult airway box. Just like Momma always said about chocolates, you never know what you're gonna get.
The open surgical cricothyroidotomy approach is probably the first learned and most familiar. Classically, it involves a scalpel, a tracheal hook, a Trousseau dilator, and a tracheostomy tube. Simpler, alternate open surgical techniques have been described, however, including one method requiring only a scalpel and an orotracheal tube if a standard kit is unavailable.
Percutaneous approaches to cricothyroidotomy are relatively new, are preferred by some physicians, and may result in faster placement with less trauma. Higher failure rates have been reported with some percutaneous techniques, however. (Br J Anaesth 2011;106:57.)
A needle is advanced through the skin, soft tissue, and cricothyroid membrane into the trachea with the classic needle-first, percutaneous approach. Tracheal entry is identified with aspiration of air. A guide wire is inserted through the needle, an incision is made with a scalpel, and finally a dilator-tracheostomy tube assembly is advanced over the guide wire (Seldinger technique).
The following article describes a new hybrid percutaneous cricothyroidotomy modification that begins with a standard open-style 2 cm vertical incision (incision-first), but is subsequently completed using the Seldinger technique.
Emergency Cricothyroidotomy: A Randomized Crossover Trial Comparing Percutaneous Techniques: Classic Needle First Versus “Incision First”
Kanji H, Thirsk W, et al
Acad Emerg Med
This randomized controlled crossover study was performed using physicians working on a modified animal model. Porcine tracheas, removed intact from their carcasses, were covered with skin and subcutaneous tissue to simulate human anatomy. A simulated kit was designed using an introducer sheath, dilator, and guide wire to minimize bias introduced by a proprietary kit and to generalize findings to multiple percutaneous devices.
Participants viewed a standardized 30-minute training presentation that reviewed each intervention: incision-first and needle-first percutaneous cricothyroidotomy. Physicians were randomly assigned to perform one of the two interventions first. Once three procedures were completed, physicians switched to the other intervention and performed three more cricothyroidotomies. Research coordinators supervised the data collection process.
Thirty physicians performed 180 procedures. The primary outcome measure was procedure time in seconds from start to the connection of the simulated ventilator apparatus.
The authors reported that the incision-first technique with a median time of 53 seconds (IQR=45.0-86.4 seconds) was significantly faster than the needle-first technique with a median time of 90 seconds (IQR=55.2-108.6 seconds; p<0.001). Overall, first attempt success was not significantly different in each group (90% vs. 93%; p=0.317), but, looking at timed success, more first attempts were completed within 90 seconds in the incision-first group (83%) than in the needle-first group (47%; p=0.006).
The authors point out several limitations of this study. The porcine model may serve as an adequate anatomical reproduction of a human trachea, but it could not simulate bleeding that might selectively affect the speed of the incision approach over the needle approach. The time difference between each group was statistically significant, but this time difference may not result in a clinically significant difference in outcome.
Perhaps the most concerning limitation, however, is the overall study design, including the decision to use a generically assembled kit that is not a clinically feasible solution. Essentially, this was a study of a modeled kit on a modeled trachea in a simulated setting which raises many concerns about real-world applicability.
The take-home point has more to do with the topic than the article reviewed. ED cricothyroidotomy may be an exceedingly rare event, but it is still the only option in the can't-intubate-can't-ventilate scenario. Find a way to practice your approach to this core skill if it has been a while since you placed a surgical airway, and you will be much better prepared when circumstances present. Keep in mind, the best surgical airway option may not be the one with which you are most familiar but the one that happens to be in your difficult airway box of chocolates. Be smart and know what's in there because remember, stupid is as stupid does, and that's all I have to say about that.
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* Read an abstract of the Academic Emergency Medicine article, “Emergency Cricothyroidotomy: A Randomized Crossover Trial Comparing Percutaneous Techniques: Classic Needle First Versus “Incision First” at http://1.usa.gov/U1Snmp.
* Read all of Dr. Lovato's past columns at http://bit.ly/JournalScan.
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© 2013 Lippincott Williams & Wilkins, Inc.