The Size 1½ ProSeal™ Laryngeal Mask Airway in Infants: A Randomized, Crossover Investigation with the Classic™ Laryngeal Mask Airway

Abstract

Many problems with the Classic laryngeal mask airway (CLMA) in infants are believed to be related to its inadequate cuff design. One of the main limitations of the CLMA is that the resulting low-pressure seal can be inadequate for positive pressure ventilation (PPV). The ProSeal LMA (PLMA), a new laryngeal mask airway with a modified cuff, has been shown to form a more effective seal than the CLMA in children. The first infant size PLMA, size 1(1/2), became available recently. We studied 30 anesthetized, nonparalyzed infants aged 15 mo (2-30 mo) and weighing 9 kg (5-12 kg). The CLMA and PLMA were inserted in random order into each patient. Airway leak pressure and maximum tidal volume were measured. Ease of insertion, quality of initial airway, and fiberoptic position were also determined. Gastric tube placement was assessed for the PLMA. The mean airway leak pressure in neutral head position (26.7 versus 18.9 cm H2O), maximum flexion (35.6 versus 28.2 cm H2O), and the mean maximum tidal volume (312 versus 260 mL) were significantly higher for the PLMA (P < 0.01). Air entered the stomach in eight patients with the CLMA but did not with the PLMA. Gastric tube placement was possible in all but one patient. In three patients, the use of the PLMA led to some degree of clinically relevant compression of the larynx. The size 1(1/2) PLMA seems to be a more suitable device for airway maintenance in infants than the same size CLMA. The ability to insert a gastric tube at the same time, and a significantly higher airway leak pressure than with the CLMA, may have important implications for its use for PPV in infants.

Usability and performance characteristics of the pediatric air-Q® intubating laryngeal airway

“…Our data on neutral OLP values and, commensurately, our V T max values for the air-Q ILA are lower than existing published data for the PLMA. [2][3][4]14 Our findings for air-Q ILA sizes 1.5 and 2.0 are similar to those previously published, 10,11 where the mean (standard deviation [SD]) OLP was 17.5 (6.4) cm H 2 O and 18.5 (1.6) cm H 2 O for size 1.5 and 15.7 (4.3) cm H 2 O for size 2.0. Our OLP findings for size 1 were higher than those by Sinha et al 11 who reported a mean (SD) OLP of 18.5 (2.1) cm H 2 O. Oropharyngeal leak pressures increase when the patient's neck is in the flexed position, a phenomenon also described with the PLMA.…”

“…Previously published studies of performance of new iterations of LMAs in adults and children have used similar group sizes. [2][3][4] Data are described with median [P25,P75] for continuous data and frequency (percent) for discrete and categorical data. Due to its observational design, this study was not powered for comparisons, and as such, no inferential methods of statistical analysis were employed.…”

“…Pediatric-sized PLMAs are also available and provide superior performance with respect to sealing pressures when compared with the LMA Classic. [2][3][4] The LMA Fastrach is a much bulkier device and is not available in pediatric sizes. Consequently, the SGD options for airway rescue in the difficult pediatric airway are limited.…”

Comparison of laryngeal mask airway (LMA)-Proseal™ and the LMA-Classic™ in ventilated children receiving neuromuscular blockade

“…Shimbori et al 18 performed a randomized, non-blinded study in 19 showed a difference in leak pressure between groups (PLMA 33 cm H 2 O; CLMA 26 cm H 2 O), as well as a higher incidence of gastric insufflation with the CLMA, with no difference in fibreoptic view. These mean leak pressures far exceed those observed in the studies previously described [15][16][17][18] as well as the current investigation. The inclusion of the size 3 PLMA, which has a posterior cuff, may account for the higher mean leak pressures observed, as well as compromisation of the fibreoptic view as seen in adult studies.…”

“…Randomized crossover studies of the PLMA vs CLMA sizes 1 ½, 15 2 16 and 2 ½ 17 have been published by Goldmann et al [15][16][17] In these studies, with the patient's head in the neutral position, the OPL by auscultation was higher for the PLMA (size 2 PLMA -18.8 cm H 2 O; size 2 CLMA -15.0 cm H 2 O). Gastric insufflation was more common for the CLMA and was absent for the PLMA.…”