[Comparison of laryngeal mask airway (LMA)- Proseal and the LMA-Classic in ventilated children receiving neuromuscular blockade].
OBJECTIVE
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).


CONCLUSIONS
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.
Lardner
David R R
DR
Division of Pediatric Anesthesia, Alberta Children's Hospital at the University of Calgary, 2888 Shaganappi Trail N.W., Calgary, Alberta T3B 6A8, Canada. david.lardner@calgaryhealthregion.ca
Cox
Robin G
RG
Ewen
Alastair
A
Dickinson
Darren
D
D002675:Child, Preschool; D004867:Equipment Design; D005336:Fiber Optic Technology; D006801:Humans; D007385:Intermittent Positive-Pressure Ventilation / Q000379:methods* / Q000706:statistics & numerical data; D007442:Intubation, Intratracheal / Q000379:methods / Q000706:statistics & numerical data; D017214:Laryngeal Masks / Q000706:statistics & numerical data*; D019148:Neuromuscular Blockade / Q000379:methods*; D011312:Pressure; D016037:Single-Blind Method