Page 60 - JSOM Winter 2023

lab setting prior to airway refresher training. No one withdrew utilize the ALD in future SC. Open-ended responses regard-
during the study period. ing ALD and training were used to solicit voluntary, open-
response feedback.
The Study Group 2 (SOF) consisted of 10 Navy SOF. All were
male (10/10) with an average length of service of 9.9 years Pre-Testing Procedure
(median 10.5, range 3–14). Although subjects were not SOF Participants filled out a pre-study questionnaire to provide
medics, all participants had completed the advanced TCCC information on sex, age, military service time, and prior cri-
course that includes airway management and SC skills training cothyrotomy experience. Confidence levels in successfully
within 12–36 months of study enrollment. No one withdrew completing different steps in the SC procedure were assessed
during the study period. on a scale of 1 to 5, with 1 indicating no confidence and
5 indicating complete confidence with the statement, “I am
SCs were performed on a 6-in-1 model (Strategic Operations, confident in successfully executing the following CricKey
https://www.strategic-operations.com/), complete with the in- steps . . .” These steps included identifying anatomic landmarks
cluded 3-D printed laryngeal inserts, and skin overlays (Laer- (AL), making an adequate incision (AI), identifying and enter-
dal, Inc., https://laerdal.com/us/) (Figure 1). A single overlay ing the airway (EA), obtaining adequate hook retraction (HR),
was used per participant. The overlay was shifted between the successfully inserting the cricothyrotomy tube into the airway
two SCs to provide an intact surface over the laryngeal insert. in one try (OT), and successfully inserting the cricothyrotomy
The Control-Cric System was used for every SC in this study. tube into the airway with multiple tries (MT).
™
No other methods were used or evaluated. The Control-Cric
features a blade with integrated tracheal hook to facilitate in- Testing Procedure
™
sertion of the Cric-Key cricothyrotomy tube and stylet obtu- All participants performed two SCs using the Control-Cric
rator. After insertion, the stylet obturator was removed and a cricothyrotomy Cric-Key kit. Prior to the first SC, the ALD
patent airway was provided via the cricothyrotomy tube. The was demonstrated to each participant using a standardized
ALD consists of a 10cc syringe, 18-gauge needle, and approx- script that took approximately 20 seconds to deliver. The par-
imately 5mL of normal saline. The partially fluid-filled syringe ticipants were randomly assigned to SC sequences of ALD/no
is advanced over the planned injection site with slight upward ALD or no ALD/ALD. Participants were tested individually
pressure/aspiration of the syringe. Once the air-filled trachea is without observing other participants. SC times were recorded
encountered, a vigorous bubbling occurs as air is drawn into to measure the overall time and the time from the start to key
the syringe. The use of the ALD was demonstrated to each points of the procedure: incision, CricKey hook placement,
participant prior to the initiation of SC with ALD. CricKey tube placement, and CricKey cuff inflation. If the par-
ticipant skipped a step but still completed the procedure, the
SC was still evaluated for correct placement. Although not a
formal data point, the omitted step was annotated on the data
collection sheet (e.g., if CricKey hook was not used).
Post-Testing Procedure
FIGURE 1 A 6-in-1 model After completion of the two SCs, the participant was imme-
(Strategic Operations, Inc.) diately administered a post-procedure questionnaire. The first
assembled with the 3-D section repeated the Likert assessment of the statement of user
printed laryngeal inserts, confidence in correct completion of key steps in the SC, with
and kin overlays (Laerdal,
Inc.) The Control-Cric 1 indicating strong disagreement and 5 strong agreement. This
™
System (Pulmodyne, time, the same question was asked twice: the first question
Inc.) and the assembled evaluated SC without ALD and the second question involved
airway localization device SC with ALD. The Likert questions were also asked to evaluate
(ALD) are placed on the ALD ease of use, likelihood of use in real SC, and increase in
mannequin torso at the
start of procedure. confidence due to refresher training. The subjects were asked
whether or not they would prefer to use the ALD in the future.
Open-ended questions were asked regarding positive and neg-
ative aspects of the ALD, as well as suggestions for changes
in the ALD design. After competition of the post-procedure
questions, the subjects were thanked for their time and their
participation was complete. Their responses were entered into
Measured Variables a password-protected spreadsheet in preparation for statistical
The primary outcome was SC first-attempt success rates, de- analysis.
fined as correct insertion into the trachea through the crico-
thyroid membrane. This was verified by direct visualization Data Analysis
of the cricothyrotomy tube location by the investigator after For this prospective randomized within-subjects design, the
the completion of the procedure and removal of the laryn- continuous data of application time and confidence ratings
geal “skin.” Secondary outcomes included application time were analyzed using repeated-measures ANOVA with paired
in seconds and user confidence ratings using a 5-point Likert t-tests. Cochran’s Q was used to analyze the categorical data
scale. These ratings included user confidence in performing the of SC success rates, with localizing pairwise McNemar’s tests.
overall SC and specific steps within the SC procedure. Dichot- Open-ended survey responses were analyzed using concept
omous questions were asked to assess the ease of ALD use analysis techniques to provide further insight into partici-
by subjects and determine whether or not the subject would pants’ confidence and performance skills.

58 | JSOM Volume 23, Edition 4 / Winter 2023