Optimum cuff pressure of flexible laryngeal mask airway for airway management in pediatric patients

Objective To determine the optimum cuff pressure of the flexible laryngeal mask airway(LMA)for airway management in pediatric patients. Methods One hundred and twenty pediatric patients undergoing strabismus surgery with general anesthesia, of American Society of Anesthesiologists physical statusⅠ or Ⅱ, aged 3-10 yr, were randomly divided into 3 groups(n=40 each)according to the cuff pressure of the flexible LMA: 20 cmH2O pressure group(group A), 40 cmH2O pressure group(group B)and 60 cmH2O pressure group(group C). The cuff was inflated to the predetermined pressure using the inflatable cuff manometer in each group.Oropharyngeal leak pressure was measured after LMA placement.Peak airway pressure and the difference between inhaled and exhaled tidal volume were recorded at 5 min of positive pressure ventilation.The LMA insertion condition, LMA removal time, and development of sore throat, hoarseness, dysphagia and abdominal distention within 24 h after operation were recorded. Results There were no significant differences in the success rate of LMA placement at first attempt, peak airway pressure, or incidence of sore throat among the three groups(P>0.05), and no hoarseness or dysphagia was found in the three groups.Compared with group A, oropharyngeal leak pressure was significantly increased, and the difference between inhaled and exhaled tidal volume and incidence of abdominal distention were decreased in B and C groups(P 0.05). Conclusion The optimum cuff pressure of the flexible LMA is 40 cmH2O when used for airway management in the pediatric patients. Key words: Laryngeal masks; Respiration, artificial; Pressure