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).

Premedication with midazolam 0.5 mg x kg(-1) po administered 20-30 min preoperatively, is effective in reducing both separation and induction anxiety in children (grade A recommendation), with minimal effect on recovery times. However improved postoperative behavioural outcomes in the postanesthesia care unit, or at home cannot be predicted on a consistent basis.

Purpose The purpose of this evidence-based clinical update is to identify the best evidence when selecting a long-acting local anesthetic agent for single-shot pediatric caudal anesthesia in children.