Abstract
Pressure-volume curves (P-V curves) before and after insertion of the laryngeal mask airway (LMA) were measured in 60 elective patients. After insertion of the LMA, clinical and fiberscopic assessment of the positioning of the LMA was performed. Fiberscopic findings were classified in three types. The larynx was alone seen in 33.3% ("Perfect type"). The epiglottis and the larynx were seen with direct fiberscopic finding of the vocal cord in 46.7% ("Intermediate type"). And, the vocal cord could not be seen directly 13.3% ("Incomplete type"). Insertion of the LMA was impossible in 6.7%. The initial inspiratory airway pressure of the "incompletetype" was always rising characteristically on the P-V curve.
The epiglottis was within mask in 60%, as judged by fioberscopic finding. Clinically, evidence of airway obstruction was not detected. On the P-V curve, however, the rise of the initial airway pressure was found out in 13.3%.
