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

Abstract

CAN J ANESTH 55: 1 www.cja-jca.org Januar y, 2008Purpose: To determine whether a functional difference exists between the size 2 laryngeal mask airway (LMA)-Classic™ (CLMA) and LMA-Proseal™ (PLMA) in anesthetized children who have received neuromuscular blockade. Airway leak during intermittent positive pressure ventilation (IPPV) and adequacy of fibreoptic laryngeal view were the primary study outcomes. Methods:A randomized, controlled, single-blinded study of 51 ASA I or II children weighing 10-20 kg was undertaken. The anesthetic technique was standardized. Following insertion of the LMA and cuff inflation to 60 cm H 2 O, we measured oropharyngeal leak pressure and gastric insufflation and leak fraction during IPPV, and evaluated the adequacy of fibreoptic view.Results: Oropharyngeal leak pressure measured by neck auscultation was higher for the PLMA compared to the CLMA (23.7 vs 16.5 cm H 2 O, P = 0.009) but, when measured by the inspiratory hold maneuver was not significantly different (24.8 vs 20.3 cm H 2 O, respectively, P = 0.217). Leak fraction values were similar for the CLMA and the PLMA (21.2%. vs 13.3%, respectively, P = 0.473). A satisfactory view of the larynx was obtained more frequently in the PLMA group (21/25 vs 10/25, P = 0.003). Gastric insufflation during leak determination was more common with the CLMA (12/26 vs 2/25 CLMA vs PLMA, respectively, P = 0.006). Conclusion:In children undergoing IPPV with neuromuscular blockade, the size 2 PLMA is associated with a higher leak pressure by auscultation and less gastric insufflation compared to the CLMA. Leak pressures assessed by manometric stability are similar with these two devices. The improved fibreoptic view of the larynx through the PLMA may be advantageous for bronchoscopy. CLMA (23,7 vs 16,5 cm H 2 O, P = 0,009) ; toutefois, lorsque celle-ci a été mesurée par manoeuvre de retenue respiratoire, il n'y a pas eu de différence significative (24,8 vs 20,3 cm H 2 O, respectivement, P = 0,217). Les valeurs de fraction de fuite étaient semblables avec le CLMA et le PLMA (21,2 % vs 13,3 %, respectivement, P = 0,473). Une vision satisfaisante du larynx a été plus fréquemment obtenue dans le groupe PLMA (21/25 vs 10/25, P = 0,003). L'insufflation gastrique pendant la détermination de la fuite a été plus fréquemment observée dans le groupe CLMA (12/26 vs 2/25 CLMA vs PLMA, respectivement, P = 0,006).

A randomised comparison of the self‐pressurised air‐QTM intubating laryngeal airway with the LMA UniqueTM in children*

“…The devices demonstrated similar airway leak pressures and overall clinical performance. The overall insertion success rates were similar to those reported by other randomised trials with the air-Q, LMA Unique, and classic LMA in children [4,13,14]. The airway tube of the air-Q SP is more flexible than the LMA Unique and could affect the subjective ease of placement, but insertion times were still faster with the air-Q SP.…”

“…The LMA Unique airway leak pressures at 10 min in this study were higher than with other randomised trials on the paediatric-sized classic LMA [14,18,19], and LMA Unique [13,16]. An increase in airway leak pressure of both devices at 10 min may indicate some degree of moulding of the device in the posterior pharynx improving airway seal.…”

“…Outcomes measured were airway leak pressure, ease and time for insertion, fibreoptic examination, incidence of gastric insufflation and complications. Median (IQR [range]) time to successful device placement was faster with the air-Q SP (12 (10-15 [5][6][7][8][9][10][11][12][13][14][15][16][17][18])) s than with the LMA-Unique (14 (12-17 [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]) s; p = 0.05). There were no statistically significant differences between the air-Q SP and LMA-Unique in initial airway leak pressures (16 (14-18 [10- …”

Supraglottic airways in difficult airway management: successes, failures, use and misuse

“…These devices all incorporate a drain tube to separate the respiratory and gastrointestinal tracts and minimise the risk of aspiration. They also create a higher oropharyngeal leak pressure compared with the first generation SADs [4][5][6][7][8] …”

Use of Supraglottic Airway Devices in the Prone Position

“…First-generation devices are simple airway tubes, whereas second-generation devices incorporate specific features to protect against gastric regurgitation and aspiration [3]. Secondgeneration SADs have a drain tube to separate the upper airway from the gastrointestinal tract, and they also create a higher oropharyngeal seal pressure compared to first-generation SADs [4][5][6][7]. These developments have broadened the indications for SADs.…”