To the Editor:—
The ProSeal ™ laryngeal mask airway (PSLMA; Laryngeal Mask Company Limited, Mahe, Seychelles) is not designed as an intubation device. However, we may need to intubate the trachea with a PSLMA in place, using it as an intubation conduit with fiberoptic guidance. This situation may occur in an unanticipated difficult intubation, when a PSLMA is used to ventilate the patient. The PSLMA might then be preferred to the LMA-Classic ™ when a potentially full stomach is a concern.1–3
On the LMA North America Web site,*which includes PSLMA specifications, it is mentioned that it is possible to introduce a 4.5-mm-ID uncuffed endotracheal tube into a size 1.5 or 2 PSLMA. We tested this information with a 4.5 uncuffed Mallinckrodt (MMJ S.A. de C.V., a Mallinckrodt Company, Juarez, Mexico) tube, and we realized that this tube does not fit into a size 1.5 PSLMA. Moreover, a size 2 PSLMA is also too small to accept easily a 4.5 uncuffed tube. However, it is possible to introduce a 4.0 uncuffed tube into a 1.5 or 2 PSLMA.
We believe that the problem may be related to variations in the outer diameter of endotracheal tubes from one company to another, inner diameter being the same.
In our opinion, this misinformation on the LMA North America Web site should be corrected because many anesthesiologists transcribe it on their difficult airway chart for emergency airway management.
†University of Sherbrooke, Sherbrooke, Quebec, Canada. marie-jose.colas@usherbrooke.ca