A randomised, non‐crossover study of the GuardianCPV™ Laryngeal Mask versus the LMA Supreme™ in paralysed, anaesthetised female patients

Abstract

We investigated the hypothesis that the oropharyngeal leak pressure would differ between the GuardianCPV TM and the LMA Supreme TM in anaesthetised patients. We randomly assigned 120 patients to receive either the GuardianCPV or the LMA Supreme for airway management. Oropharyngeal leak pressure was measured during cuff inflation from 0 to 40 ml in 10-ml steps. In addition, intracuff pressure, fibreoptic position of the airway and drain tube, device insertion success, ventilation success, blood staining and airway morbidity were determined. Mean (SD) oropharyngeal leak pressures for clinically acceptable cuff volumes of 20-40 ml were 31 (7) cmH 2 O for the GuardianCPV and 27 (7) cmH 2 O for the LMA Supreme (p < 0.0001); mean (SD) intracuff pressures were 68 (33) cmH 2 O and 88 (43) cmH 2 O (p < 0.0001), respectively. We found no differences in device insertion success, ventilation success, fibreoptic position of the airway and drain tube, blood staining or airway morbidity. We conclude that the oropharyngeal leak pressure is better for the GuardianCPV than for the LMA Supreme in anaesthetised patients.

A Cross-Sectional Study Evaluating the GuardianCPVTM Supraglottic Airway Device in a Clinical Setting

“…Our study found that the success rate achieved at TNH with the Guardian (78%) was lower than that documented in Tiefenthaler et al (100%) [10] and significantly lower than a reasonable rate of 95%; it was otherwise more comparable with other success rates observed for other second-generation SADs, such as the Supreme [1][2][3]5,6,9], the previous SAD model employed at TNH. Success with the Guardian was associated with perceived ease of insertion, higher seal pressures, and reduced need for SAD repositioning.…”

“…Tiefenthaler et al found that both Guardian and Supreme yielded 100% successful insertion rates (n=60 each) with trained anesthetists, and that the Guardian offered slightly superior OLP to the Supreme (31 vs. 27 cmH 2 O, p<0.0001) [10]. Some limitations of this study include all patients being female and paralyzed, and all insertions having been performed by one of two consultant anesthetists experienced in the use of both models.…”

“…This was in contrast to the technique reported in Tiefenthaler et al where both operators in the paper exclusively used a finger-guided technique [10]. The original manufacturer, Ultimate Medical, also recommended using the fingerguided technique for their product (AM Keogh, personal communication).…”

“…The existing literature for the Guardian LMA reports 100% success rate. [10,11] Using G * Power [12], a sample size of at least 50 was needed to identify a statistically-significant difference (one-tailed, α=0.05, β=0.80) from an expected success rate of 95% to an actual success rate of 80%.…”

“…Other popular second-generation SADs (LMA Supreme TM , i-gel ® , Proseal LMA TM ) typically achieve success rates of 71 to 100% [1][2][3][4][5][6][7][8][9]. At the time that this study was performed, there was only one known study in the literature that specifically assessed the Guardian, comparing it with the Supreme [10]. According to that study, efficacy was equivalent between both models, with equivalent insertion success rates on first attempt (100%), and slightly superior oropharyngeal leak pressure (OLP) for the Guardian compared to the Supreme.…”