Clinical performance of the LMA Protector™ airway in moderately obese patients

Abstract

Background: The 4th National Audit Project of The Royal College of Anaesthetists and The Difficult Airway Society (NAP4) reported a higher incidence of supraglottic airway device (SAD) related pulmonary aspiration in obese patients especially with the first-generation SADs. The latest single-use SAD, the Protector™ provides a functional separation of the respiratory and digestive tracts and its laryngeal cuff with two ports allowing additional suction in tandem with the insertion of a gastric tube. The laryngeal cuff of LMA Protector™ allows a large catchment reservoir in the event of gastric content aspiration. Methods: We evaluated the performance characteristics of the LMA Protector™ in 30 unparalysed, moderately obese patients. First attempt insertion rate, time for insertion, oropharyngeal leak pressure (OLP), and incidence of complications were recorded. Results: We found high first and second attempt insertion rates of 28(93%) and 1(33%) respectively, with one failed attempt where no capnography trace could be detected, presumably from a downfolded device tip. The LMA Protector™ was inserted rapidly in 21.0(4.0) seconds and demonstrated high OLP of 31.8(5.4) cmH2O. Fibreoptic assessment showed a clear view of vocal cords in 93%. The incidence of blood staining on removal of device was 48%, postoperative sore throat 27%, dysphagia 10% and dysphonia 20% (all self-limiting, resolving a few hours postoperatively). Conclusions: We conclude that the LMA Protector™ was associated with easy, expedient first attempt insertion success, demonstrating high oropharyngeal pressures and good anatomical position in the moderately obese population, with relatively low postoperative airway morbidity.

Assessing a novel second generation laryngeal mask airway using the ‘ADEPT’ approach: results from the LMA® Protector™ observational study

“…Furthermore, this question was posed early on admission to the postoperative recovery unit, whereas other studies waited much longer to record this outcome, e.g. 18-24 h after operation [21][22][23][24]. Nevertheless our reported minor complication rate is not prohibitive to use of the device.…”

“…Ours is not the first reported trial of the LMA Protector. Sng et al’s description in 2017 [ 22 ] was in fact contemporaneous with the planning of our own trial, and the delays we then encountered are described in the accompanying article [ 9 ], and since then there exist over a dozen reports, including description of its use in different patient positions, emergency and elective settings, and for facilitating use of fibrescopy [ 13 , 23 , 24 ]. However, whereas most of these are individual case series or relatively small (but albeit appropriately statistically powered) randomised trials, ours is arguably the first study of a diverse patient cohort in real world settings.…”

“…Nevertheless our reported minor complication rate is not prohibitive to use of the device. The presence of blood on supraglottic airway devices upon removal is common [21][22][23][24]. Most studies report the occurrence of visible bloodstaining ranging between 0 and 50% [21][22][23][24][25].…”

“…The presence of blood on supraglottic airway devices upon removal is common [21][22][23][24]. Most studies report the occurrence of visible bloodstaining ranging between 0 and 50% [21][22][23][24][25]. The wide range in these figures may be attributed to slight differences in device size, material or shape and also due to differences in device insertion techniques affecting minor trauma to the oropharyngeal mucosa.…”

Comparison of the efficacy of supraglottic airway devices in low-risk adult patients: a network meta-analysis and systematic review

“…The high OLP of the Protector may be attributable to the fact that it is made of medical grade silicone. Moreover, its curve airway tube and inflatable cuff may allow it to better conforms to the anatomical contours of an individual’s hypopharynx 10 . Other SADs also attained better OLP than that of the C-LMA, and this finding is consistent with that of a recent network meta-analysis of SADs for pediatric patients, which indicated that the I-gel, Cobra and P-LMA achieved 3.4 to 4.6 cmH 2 O higher OLP than that of the C-LMA 11 .…”