Page 82 - Journal of Special Operations Medicine - Fall 2014

Laryngeal Mask Airway Exchange Using a
Gum Elastic Bougie With a Rotational Twist Technique

Stewart Stancil, MD; Joel Miller, MD; Mark Riddle, DO

ABSTRACT
Previous studies have sought to determine the feasibil- maintain the supraglottic airway or replace it with a
ity of exchanging the laryngeal mask airway (LMA) for more definitive ETT. SADs are not considered defini-
an endotracheal tube (ETT) over a gum elastic bougie tive airways, and aspiration is a known risk factor with
(GEB) and found the practice to have a success rate of their prolonged use. However, if the patient is able to
about 50%. It has been speculated that the poor success be oxygenated with the supraglottic device, there can
rate may be due to the upward angle of the bougie tip be trepidation regarding its removal in case of difficulty
meeting resistance against the anterior laryngeal wall. with ETT placement.
The use of a 90- to 180-degree twist technique to angle
the bougie tip away from the anterior tracheal wall and Once intubating conditions have been maximized,
caudally along the trachea theoretically could improve such as when the patient has arrived in the emergency
results. We conducted a prospective cadaveric study to department, the SAD can then be exchanged for the
determine if the use of a bougie 90- to 180-degree twist definitive standard ETT. Removal of a functioning su-
technique or the use of a more flexible pediatric bou- praglottic device to place an ETT is not without risk.
gie would improve previously published success rates. Previous studies have attempted to describe techniques
Emergency medicine personnel attempted exchange of to facilitate the exchange of an LMA with an ETT,
an LMA for an ETT over a GEB using a twisting tech- specifically addressing whether passage of a bougie
nique. Despite using the twisting technique, successful through the LMA would result in tracheal placement,
exchange over a bougie remained at 50%, similar to thus allowing endotracheal intubation over the bougie.
previous studies. Using a smaller, more flexible pediatric Miller et al. found that a bougie can be successfully
bougie led to a successful exchange in only 28% of at- guided through a standard LMA with success rates of
tempts. In this study, the adding of a twist technique or 52%. A 50% success rate was confirmed in a subse-
2
using a pediatric bougie did not result in consistent suc- quent study by Mitchell et al. Shah et al. had similar
3
cessful exchange to an ETT from an LMA. first attempt success rates in a study to evaluate bougie
success with direct laryngoscopy and postulated that
Keywords: laryngeal mask airway, endotracheal tube, gum the reason for failure may largely be due to the bou-
elastic bougie, supraglottic airway devices, intubation, air- gie coudé tip becoming stuck against the anterior oro-
way, tube exchange pharynx. To further investigate this observation from
4
previous studies, we have designed an experiment to
determine whether a twisting technique or a more flex-
ible pediatric bougie might improve success rates in
Introduction
tube exchange.
Supraglottic airway devices (SADs) are commonly used
in the prehospital setting as both a rescue device and, This study was conducted to evaluate the success rate
increasingly, a primary airway adjunct. Additionally, of exchanging a standard LMA for an ETT by using a
SADs are being used more often as primary airway de- GEB as an introducer device, with a 90- to 180-degree
vices in light of recent recommendations to minimize rotation (coudé tip rotated from anterior to caudal as
chest compression interruptions during cardiopulmo- it passes the angle of the LMA). It is hypothesized that
nary resuscitation. The shift was reflected initially in as the tip of the bougie exits the LMA and makes con-
the 2005 American Heart Association Advanced Car- tact with the anterior hypopharynx, a 90- to 180-degree
diac Life Support standards and was continued in the twisting motion as the bougie is advanced will direct the
2010 standards. On stabilization in the hospital envi- tip off the pharyngeal wall and allow the tip to proceed
1
ronment, the provider must make a decision to either caudally through the vocal cords.

74