Page 27 - Journal of Special Operations Medicine - Fall 2015

and a diameter of approximately 5mm. It was designed subcutaneous tissue by tenting the skin. No skin tent-
to fit into a 5.0mm interior diameter cuffed Melker cri- ing is present if the device is in the trachea. Having both
cothyroidotomy airway cannula. The CK combines the tactile and visual confirmation of proper placement is
functions of a tracheal hook, stylet, dilator, and bougie critical in the noisy, low-light prehospital setting. A con-
when incorporated with the Melker airway (Figure 1). ventional gum elastic bougie is approximately 70cm in
The CK design is based on the shape and curvature of length and is designed for oral insertion, making it some-
Levitan’s scope used in a previous study of fiber optic– what ungainly for use in SC due to its excessive length,
guided SC in a sheep model. 37 whereas the total length of the CK is less than 20cm.

If the CK is correctly inserted into the trachea, the op- In a recent crossover study of 15 US Army 68 Whis-
erator may appreciate the vibrations of the anterior key medics, the CK technique took less time to perform
tracheal cartilaginous rings as the distal tip of the CK and had no first attempt failures when compared with
passes over them. If the CK is inserted into the subcu- a standard open surgical technique with this group of
taneous tissue and not in the trachea, the operator can relatively inexperienced medics performing the proce-
see the distal tip tent the skin of the neck. If the device dure on fresh human cadavers. 38
is correctly inserted into the trachea, no skin tenting is
visualized. All of the CK insertions (15 of 15) were successful on
the first attempt whereas 66% (10 of 15) in the stan-
The CK technique eliminates several potential complica- dard cricothyroidotomy group were successful on the
tions, errors, and sources of procedural difficulty. We first attempt (p = .042). Two participants required mul-
recommend a vertical midline skin incision followed by tiple attempts to place the airway in the standard group,
direct visualization of the CTM. This allows maximal one required two and another required three attempts,
exposure of the anatomy and extension of the incision if but were ultimately successful. Three participants in the
further exposure is needed while decreasing the risk of standard group failed to cannulate the airway. One par-
bleeding. While the potential for complications remains ticipant placed the airway into the esophagus. Two oth-
with an open technique, complications associated with ers placed it into the soft tissue of the neck. Procedure
wire-guided and percutaneous techniques are avoided. time for the CK was faster, with a median time of 34
Visualizing the CTM reduces the likelihood of subcuta- seconds (95% confidence interval [CI], 33–37 seconds)
neous or esophageal placement. We believe adequate ex- compared with 65 seconds using the standard technique
posure, visualization, and direct palpation of the CTM (95% CI, 52–92 seconds; p = .001).
is critical for providers who do not have extensive expe-
rience with surgical airways. We incise the CTM and in- Based largely on the findings of this study, Combat units
sert the tip of the device into the trachea. The tip of the have begun to field this device for their Combat medics.
device secures the opening into the trachea and gives the Initial feedback has been positive: “I received a quick
operator the ability to lift and manipulate the trachea. class from LTC Mabry on the device, then taught a new
The device has a blunt tip that is curved upward, thus medic how to use the device . . . The medic had a cric
minimizing the risk of injury to the membranous trachea [cricothyroidotomy] in place in under 25 seconds and
or esophagus. Since the CK combines the functions of secured in less than a minute . . . This device will be the
both the bougie and a dilator, and incorporates them standard of equipment used by all Ranger Medics for
within the airway cannula as a single unit, the result is surgical cricothyroidotomy (Personal communication,
a much more compact/efficient device that is easier to MSG Curt Conklin, 75th Ranger Regiment; 26 Febru-
handle and requires fewer steps or additional equipment ary 2015).
such as forceps, tracheal hooks, or dilators.
Note that the study demonstrating success with the
Like the BAC, the CK technique also provides tactile CricKey entailed five repetitions of both the study CK
feedback if the device is placed correctly in the airway procedure and the standard surgical airway control pro-
as the tip passes over the tracheal rings. The coudé tip cedure. Five is the minimum number of procedures rec-
of the CK is always oriented anteriorly, allowing it to ommended in a recent review of surgical airway training
consistently make contact with the tracheal rings as it methodology to achieve proficiency in the technique.
39
is advanced caudad. This is not always the case when Since incorrect location of the incision is a demonstrated
using the BAC. Although the BAC is initially inserted cause of failure in the performance of surgical airways,
through the CTM with the coudé tip oriented anteriorly, training in this procedure should include anatomically
inadvertent rotation of the bougie 180 degrees aligns the precise airway manikins as well as the use a skin marker
coudé tip with the smooth posterior wall of the trachea, to demonstrate knowledge of the correct position of the
where no vibrations can be felt. The CK also provides incision on the neck of a fellow student in the training
visual feedback if the device is placed incorrectly into the class. 39

Emergency Cricothyroidotomy in TCCC 15