Page 21 - JSOM Summer 2023

Military Standard Testing of Commercially Available
Supraglottic Airway Devices for Use in a Military Combat Setting

1
3
Carlos Bedolla, MS ; Danielius Zilevicius, MS ; Grant Copeland, MS ;
2
7
4
Marisa Guerra, BS ; Sophia Salazar, BS ; Michael D. April, MD, DPhil, MSc ; Brit Long, MD ;
5
6
9
Jason F. Naylor, PA-C ; Robert A. De Lorenzo, MD, MSM, MSCI ;
8
10
11
Steven G. Schauer, DO, MS *; R. Lyle Hood, PhD *
ABSTRACT
Introduction: Airway obstruction is the second leading cause Introduction
of death on the battlefield. The harsh conditions of the mili- 1
tary combat setting require that devices be able to withstand The landmark paper by Eastridge et al established that airway
extreme circumstances. Military standards (MIL-STD) testing obstruction is the second leading cause of potentially survivable
is necessary before devices are fielded. We sought to determine death on the battlefield among US forces. More recent data es-
the ability of supraglottic airway (SGA) devices to withstand tablish that treating airway obstruction, together with respira-
MIL-STD testing. Methods: We tested 10 SGA models accord- tory compromise and noncompressible truncal hemorrhage, are
ing to nine MIL-STD-810H test methods. We selected these the key foci to improve survival in prehospital combat casualty
2,3
tests by polling five military and civilian emergency-medicine care. Data from the REACH (Registry of Emergency Airways
subject matter experts (SMEs), who weighed the relevance of Arriving at Combat Hospitals) study in the early phases of the
each test. We performed tests on three devices for each model, Iraq war showed both a general underutilization of advanced
with operational and visual examinations, to assign a score airway interventions and high complication rates in those in-
4
(1 to 10) for each device after each test. We calculated the fi- stances when they were employed. More recently published
nal score of each SGA model by averaging the score of each data demonstrate high mortality associated with advanced air-
5,6
device and multiplying that by the weight for each test, for way intervention in the prehospital combat setting. Schauer
7,8
a possible final score of 2.6 to 26.3. Results: The scores for et al found similar clinical outcomes for cricothyrotomy SGA
the SGA models were LMA Classic Airway, 25.9; AuraGain device placement in combat settings, suggesting that SGAs may
Disposable Laryngeal Mask, 25.5; i-gel Supraglottic Airway, be a viable alternative to surgical airways.
25.2; Solus Laryngeal Mask Airway, 24.4; LMA Fastrach Air-
way, 24.4; AuraStraight Disposable Laryngeal Mask, 24.1; Despite this literature, utilization and success rates in prehos-
King LTS-D Disposable Laryngeal Tube, 22.1; LMA Supreme pital combat airway have not improved. The Committee on
Airway, 21.0; air-Q Disposable Intubating Laryngeal Airway, Tactical Combat Casualty Care (CoTCCC) does list airway
20.1; and Baska Mask Supraglottic Airway, 18.1. The limited optimization among the top five battlefield research and de-
(one to three) samples available for testing provide adequate velopment priorities, but meaningful technological advances
9
preliminary information but restrict the range of failures that remain elusive. In the interim, minor changes to the TCCC
could be discovered. Conclusions: Lower scoring SGA models guidelines have produced modest refinements with respect to
may not be optimal for military field use. Models scoring suf- airway intervention medical protocols, namely the early em-
ficiently close to the top performers (LMA Classic, AuraGain, phasis on the King Laryngeal Tracheal device and more recent
i-gel, Solus, LMA Fastrach, AuraStraight) may be viable for emphasis on the use of the i-gel devices. Notably, these changes
use in the military setting. The findings of our testing should arose from expert opinion, with only sparse data available to
10
help guide device procurement appropriate for different bat- inform. In any event, Schauer et al observed that combat
tlefield conditions. medics lacked access to many of these devices altogether.
Keywords: supraglottic; extraglottic; military; standard; test- Because TCCC guidelines recommend SGA use, it is likely that
ing; combat; medic their fielding and use will increase over time. To ensure that the
devices recommended now or in the future are suitable for the
far-forward battlefield environment, they must, at a minimum,

*Correspondence to steven.g.schauer.mil@health.mil and lyle.hood@utsa.edu
1 Carlos Bedolla is affiliated with the Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX.
2 Danielius Zilevicius is affiliated with the Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX.
4
3 Grant Copeland is affiliated with the Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX. Marisa
Guerra is affiliated with the Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX. Sophia Salazar
5
is affiliated with the Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX. LTC Michael D. April
6
is affiliated with the 40th Forward Resuscitative Surgical Team, Fort Carson, CO, and the Uniformed Services University of the Health Sciences,
Bethesda, MD. Maj Brit Long is affiliated with Brooke Army Medical Center, Joint Base San Antonio–Fort Sam Houston, TX, Uniformed Services
7
University of the Health Sciences, Bethesda, MD, and the 59th Medical Wing, JBSA Lackland, TX. LTC Jason F. Naylor is affiliated with Madigan
8
Army Medical Center, Joint Base Lewis McChord, WA. Dr Robert A. De Lorenzo is affiliated with the Department of Mechanical Engineering,
9
The University of Texas at San Antonio, San Antonio, TX and with the Department of Emergency Medicine, University of Texas Health Science
Center at San Antonio, TX. LTC Steven G. Schauer is affiliated with the Uniformed Services University of the Health Sciences, Bethesda, MD,
10
with the US Army Institute of Surgical Research, Joint Base San Antonio–Fort Sam Houston, and with Brooke Army Medical Center, Joint Base
San Antonio–Fort Sam Houston, TX. Dr R. Lyle Hood is affiliated with the Department of Mechanical Engineering, The University of Texas at
11
San Antonio, San Antonio, TX, and with the Department of Emergency Medicine, University of Texas Health Science Center at San Antonio, TX.
19