Page 84 - Journal of Special Operations Medicine - Fall 2014

tracheal bougie placement rates of 50% using the stan- technique is successful only 50% of the time, the position
dard LMA. 3 of the LMA is maintained and failure to pass the bougie
should not affect the function of the LMA for continued
A June 2012 article by Wong et al. published in the Ca- airway management while further techniques for defini-
nadian Journal of Anesthesia summarized several stud- tive airway management are considered.
ies conducted on LMA-guided endotracheal intubation
and highlighted the inherent difficulties with direct blind
placement of standard ETTs through supraglottic de- Limitations
vices. To aid with ETT placement, the use of “a catheter The study is limited by the use of a cadaveric model.
7
or introducer,” such as a GEB, was suggested to be help- This could have adversely affected results as the airway
ful. The article further listed studies conducted thus far on tissues are often distorted. Another problem is the cre-
blind GEB/LMA ETT intubation, which evaluated factors ation of false passages and airway trauma to the cadav-
such as (a) cricoid pressure (Gabbott et al. concluded that ers with repeated intubation attempts. In recognition of
cricoid pressure decreased bougie tracheal insertion suc- this, each participant was limited to only one attempt
cess), (b) the effect of the sniffing position with regards to with each bougie. The success rates may have improved
8
blind bougie placement through the LMA (Ahmed et al. had each participant been given a second attempt, thus
found that the sniffing position resulted in a clinically in- learning from the first attempt. This conjecture is sup-
significant improvement in success), and (c) reliability of ported by the Shah et al. study, which found that two-at-
9
blind bougie placement through an LMA for endotracheal tempt success rates reached 79.6%. Another limitation
4
intubation affected by experience level (Miller et al, find- to the study is that the participants were not allowed
ing that there was no significant difference in success rates time to determine via various techniques whether the
corresponding to years of training and practice). 2 bougie had been placed in the trachea. This could have
been accomplished by using standard maneuvers such
Most of the studies regarding blind bougie passage as progressing the bougie advancement to the carina, as
through a Classic LMA for endotracheal intubation re- well as acoustical and tactile sensation of the bougie tip
sulted in success rates below 52%. The reason for the making contact with the tracheal rings.
high rate of failure is uncertain. A study by Shah et al.
performed during real-time emergency department in-
tubations speculated on techniques to improve success. Conclusion
The authors found a first-pass success rate of 50% and a The current study was performed to quantify the benefit
multiple-pass success rate of 79.6% when performed by of a 90- to 180-degree counterclockwise rotation as the
both emergency medicine residents and experienced staff bougie entered the hypopharynx and to determine if there
emergency physicians. Among the failures, 52% reported was any advantage in using a pediatric bougie instead of
failure to pass the GEB beyond the hypopharynx and a standard adult bougie. The results showed no improve-
24% reported they were unable to thread the ETT over ment from the 50% success rate seen in prior studies. The
the bougie. It was suggested in the article that the GEB pediatric bougie proved to be less effective than the adult
attempts became stuck in the hypopharynx and that, “It bougie. It was found that there were only small differ-
is possible that in an attempt to pass the bougie anteriorly ences in success rates across the levels of experience. Some
or upward, the bougie is bending in the hypopharynx.” providers achieved much higher success rates, suggesting
4
The authors also noted and cited previous studies that there may be an as-yet-undescribed optimal technique.
demonstrate that success rates of threading the ETT are While this technique may only achieve 50% first-pass
significantly higher when rotating the ETT counterclock- success, the position of the LMA is maintained, thus sug-
wise 90 degrees before passing it through the cords. 10 gesting there may be little downside in attempting this
technique before the removal of a functioning LMA.
This study demonstrated an overall success rate of ap-
proximately 50%. The pediatric bougie was significantly
less effective. Although there was only a 50% success Disclosures
rate, it was noted that some participants were consis- The authors have nothing to disclose. The authors have
tently more successful (31.3% of participants were suc- no financial disclosures or conflicts of interest. There
cessful 75% of the time). This may indicate that indeed was no funding for the study.
there is an optimal technique for successful passage of the
bougie, although we were not able to consistently rep-
licate it. It may be the case that more training on tech- Approval
nique and focusing not only on rotation but on actual Submissions with PAO approval with the caveat that
observation of the bougie coudé tip position before and this article does not reflect the position of CRDAMC
during insertion would improve success rates. While this Hospital Command, Fort Hood, or the US Army.

76 Journal of Special Operations Medicine Volume 14, Edition 3/Fall 2014