To the Editor:--The successful use of a laryngeal mask airway (LMA) in three patients with undiagnosed lingual tonsil hyperplasia has been described by Biro and Shahinian. The LMA was used without apparent difficulty to treat a "cannot intubate, cannot ventilate" situation occurring unexpectedly at the time of induction. We cared for a patient who was found to have lingual tonsil hyperplasia at the time of induction but in whom the lungs could be ventilated with only marginal success via an LMA.
A 55-yr-old woman scheduled for ankle surgery had normal preoperative airway examination results. After induction with propofol and rocuronium, standard mask ventilation, eventually using both an oral airway and two anesthesiologists, yielded no detectable gas exchange. Multiple attempts at laryngoscopy revealed only an abundance of soft, redundant, almost papillomatous appearing tissue at the base of the tongue. Transtracheal jet ventilation was attempted, but after several seconds, subcutaneous crepitus occurred without evidence of gas exchange. The catheter was removed, and a #4 LMA was inserted easily. Although gas exchange was occurring, the highest pulse oximeter reading attained was 92% with an FIO2of 1. The inadequate gas exchange was confirmed further by a simultaneous blood gas analysis (PaO262 mmHg). Using a fiberoptic bronchoscope through the LMA, only a very small portion of the vocal cords could be seen posteriorly. The anterior aspect of the cords was covered with folds of hyperplastic tissue from the lingual tonsil. The bronchoscope was guided through a tiny opening between the cords, and a normal appearing trachea was identified. We were unable, however, to pass a 6.0 mm-ID endotracheal tube over the bronchoscope through the vocal cords. The SpO2decreased to 30% during this apneic intubation attempt, increasing to 85% over about 1 min after the bronchoscope was removed and ventilation resumed via the LMA. Because of the apparently edematous periglottic tissue and decreasing pulse oximeter readings, it was decided to proceed to a cricothyrotomy. Subsequent biopsy revealed a clear diagnosis of lingual tonsillar hyperplasia.
This case illustrates, as has been described previously, that the LMA can be a life-saving tool. It also serves as a reminder that this tool at times may be of only limited efficacy as a superglottic ventilatory conduit in the presence of a significant periglottic obstruction. .
Brent W. Fundingsland, M.D., Clinical Instructor.
Jonathan L. Benumof, M.D., Professor, Department of Anesthesiology, University of California San Diego Medical Center, 200 West Arbor Drive, San Diego, California 92103-8770.