Sialadenopathy with the Laryngeal Mask Airway

Abstract

To the Editor: Hooda and Gupta [1] reported the first case of acute transient sialadenopathy associated with the laryngeal mask airway (LMA). In their Discussion, they state that there was no clinical evidence of malpositioning to account for this complication, but the Figure thatthey provide suggests otherwise and hints at a possible etiology. Their Figure 1shows that the LMA tube was not in the midline and was probably protruding excessively from the mouth. This suggests that the cuff was either rotated or subject to a rotational force, and either not inserted deeply enough or overinflated. The authors did not state the volume used to inflate the cuff. Although ease of manual ventilation is associated with correct LMA placement [2], adequate function is still possible when the LMA is grossly malpositioned [3]. Figure 1also shows that the tube is being pulled cranially by the anesthesia breathing system against its natural caudal curve. Such a force would tend to displace the cuff from the hypopharynx and lever it anteriorly with the teeth functioning as a fulcrum. This would increase the pressure exerted by the cuff against anterior structures, such as the base of tongue. Finally, indirect evidence that sialadenopathy is related to malposition is that the mean mucosal pressure exerted by the LMA cuff at the base of the tongue is only 27 cm H2 O when the device is inserted/fixed correctly and fully inflated [4]. It is unlikely that such low pressures could cause sialadenopathy by a direct mechanical effect. We conclude that the combination of malpositioning and additional anterior pressure might be sufficient to produce sialadenopathy in some patients. The risk of this complication should be minimized if the LMA is inserted, fixed, and inflated correctly [5]. J. Brimacombe, MB ChB, FRCA, MD University of Queensland; Cairns Base Hospital, Australia C. Keller, MD University of Innsbruck, Innsbruck, Austria