Page 25 - JSOM Winter 2017

to ETI for surgical patients in the laparoscopic pneumoperi- incidents of regurgitation. The Polat study also found that
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toneum and Trendelenburg positions. In a prospective, con- the i-gel had a shorter insertion time and a better fiberoptic
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trolled, randomized trial, in 80 anesthetized elective surgery view than the LMA Classic. In a study designed to examine
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patients, the insertion success rate was higher in the i-gel group the use of EGAs in casualties wearing CBRN-protective equip-
(100% on the first attempt) than in the Proseal-LMA group ment, the i-gel was found to have the shortest insertion time
(82.5% on the first attempt). The mean insertion time for the of the EGAs tested. 36
i-gel group was significantly faster than that of the Proseal-
LMA group (i-gel: 8 ± 3 seconds vs P-LMA: 13 ± 5 seconds). Four studies have noted that the LMA Supreme performed
The airway leakage pressures were similar. The authors con- well in comparison to other EGAs. 17,29,72,73 In a study of mili-
cluded that the i-gel was the preferred EGA between the two. 5 tary novices comparing five different EGAs, the LMA Supreme
first-attempt success rate was 95% compared to the i-gel first
Another randomized, single-blind, controlled study with 64 attempt success rate of 87%, although the final success rate for
anaesthetized and paralyzed patients compared the i-gel and both devices was 99%. The insertion time for the i-gel was 74
the LMA-Classic. Successful insertion time was significantly seconds compared to the LMA Supreme’s 70 seconds. Thirty-
shorter for the i-gel. Joly and coauthors conducted a pro- seven percent of study participants rated the i-gel as “very
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spective randomized study of the i-gel vs the LMA-Supreme in easy to insert” vs 61% for the LMA Supreme. The authors
100 elective surgery patients who had procedures done under concluded that: “Most study parameters for the Supreme
general anesthesia. Both EGAs were inserted successfully in LMA and i-gel were found to be superior to the other three
92% of patients. The authors found no significant difference tested supraglottic airway devices when inserted by military
in the leak pressures between the two devices. The insertion novices.” The 2012 Ragazzi study used airway management
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time was shorter with the i-gel (19 seconds) than with the novices who were randomly assigned to use the LMA Supreme
LMA Supreme (27 sec) and the vocal cords were completely or the i-gel in 80 patients undergoing breast surgery. The first-
visualized in 70% of i-gel patients in contrast to 50% of LMA attempt insertion success rate was significantly higher for the
Supreme patients. In a large 2012 study of 2049 i-gel uses LMA Supreme device (77%) than for the i-gel (54%); p =
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in the operating room, the overall success rate was 96%. The .029). There were also more insertion failures with the i-gel
i-gel insertion was deemed “very easy or easy” in 92% of pa- than with the LMA Supreme. This study noted that more pa-
tients. The authors concluded that: “The i-gel is a reliable tients complained of pharyngolaryngeal pain with the LMA
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supraglottic airway device failing in <5% and providing high Supreme (44%) than with the i-gel (20%; p = .053). The au-
airway leak pressures.” 16 thors concluded that “We found better first time success rate,
fewer failures, and a better seal with the LMA Supreme com-
A 2012 prospective, randomized trial studied two groups of pared with the i-gel, indicating that the LMA Supreme may be
spontaneously breathing patients who had a variety of surgical preferable for emergency airway use by novices.” 73
procedures performed under general anesthesia. The i-gel was
used for 40 patients and the LMA Classic was used for an- The LMA-Supreme, however, is more expensive than the i-
other group of 40. The insertion of the i-gel was significantly gel—$25 per device for the LMA Supreme vs $10.18 per unit
faster (15.6 seconds) compared to 26.2 for the LMA Classic. for the i-gel (personnel communication, Major Craig Stache-
The leak pressure was also found to be higher for the i-gel. wicz, DHA Medical Logistics, 10 July 2017). It also requires
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Jaoua’s 2014 study of 100 elective surgery patients undergo- the extra steps of inflating the LMA-Supreme’s cuff with air
ing general anesthesia found a successful i-gel insertion rate of and checking the cuff pressure. Further, when the casualty
99%. The device was able to be inserted on the first attempt is transported to definitive care on a helicopter, the pressure
in 92% of cases and the i-gel was rated as easy to use in 99% in the air-filled cuff on the LMA-Supreme will increase and
of cases. The median insertion time was 13 seconds. The con- decrease with altitude changes. The requirement to monitor
clusion from the study was that the i-gel “can be used safely cuff pressure and add or remove air as needed to maintain
and effectively in patients undergoing short-duration elective the target pressure adds another task that must be performed
surgery because the i-gel has a very good insertion success rate by busy medics on evacuation platforms. This is a challenge,
and few complications.” 6 since these medics may have several critical casualties to care
for during the flight. It also means that they will need to train
The study by Russo et al. examined the i-gel, the LMA Su- on and carry a cuff manometer.
preme, and the Laryngeal Tube Suction-D in elective surgery
patients with groups of 40 patients each. The insertion success Having a single device identified as the EGA of choice in TCCC
rates for the i-gel and the LMA-Supreme were both reported would allow for better interoperability between combat units.
as 95%, while the LTS-D had a succcess rate of 70%. An Based on the evidence above, the i-gel is the strongest can-
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Australian study compared the i-gel with the Portex Soft Seal didate as the standard EGA in TCCC. The i-gel is presently
Laryngeal Mask (PSS-LM) in patients who had suffered an the only EGA that is used in for ground and helicopter trans-
out-of-hospital cardiac arrest. Fifty-one patients were ran- port of trauma patients in the University of Cincinatti Medical
domized for this study. The insertion success rate was 90% for Center’s trauma system and the acceptance of the i-gel in that
the i-gel as compared to 57% for the PSS-LM. Although one EMS system has been very high, as noted by one of the authors
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cadaver study found that the i-gel had a lower leak pressure (EJO), who went on to propose that i-gel be selected as the
than the Proseal LMA and the LMA Classic, a larger study EGA of choice in TCCC. The i-gel EGA is shown in Figure 1.
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by Polat in 2015 also compared the i-gel and the LMA-Classic
and found regurgitation not to be a problem. This study had EGAs in Tactical Field Care as Well as TACEVAC Care
groups of 60 patients for each of the two devices. The findings
from that study were similar to the Atef study mentioned pre- The TCCC Guidelines previously did not recommend the use
viously. Both devices were reported to perform well without of extraglottic airways until the TACEVC phase of care. In
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Extraglottic Airways in Tactical Combat Casualty Care | 23