To the Editor:-We read with interest the case report by Uezona et al. regarding the use of the cuffed oropharyngeal airway (COPA) as an adjunct to the management of the difficult airway.
The authors comment on the loss of oropharyngeal tone after general anesthesia and the use of a COPA to maintain a patent airway with spontaneous ventilation during fiberscopy by connecting the anesthesia circuit directly to the 15-mm connector of the COPA. The authors state “the COPA eliminates the need of an assistant who holds the mask and applies a chin lift/jaw thrust, which may make this device more useful than the endoscopic mask.” In our experience, however, the COPA does not always eliminate the need to apply a chin lift/jaw thrust, and, in the first of the two cases reported, an assistant provided “slight neck extension and modest chin lift” for an adequate airway. Also, a recent study has suggested that, despite good position of the COPA, as confirmed by fiberscopic examination, the cuff is not sealed tightly in the upper pharynx, and ventilation of the lungs with positive pressure is more secure with a face mask while the COPA is in place and inflated than when it is attached directly to the breathing system.
The authors also describe a series of 25 patients with normal airway anatomy who underwent fiberoptic intubation alongside the COPA. As the fiberscope was passed down the nostril it was deviated from the midline, forcing the fiberscope to pass around the lateral side of the cuff of the COPA with a view of the larynx at the 9-o'clock position. A 90 [degree sign] rotation and a 90 [degree sign] downward bending of the distal tip was required for visualization of the vocal cords. This technique may not be optimal in a patient with a difficult airway in which a midline approach will most readily direct the fiberscope to the larynx. The COPA in this respect compares unfavorably with a number of devices available [3,4,5]that allow the fiberscope to enter the pharynx in the midline and that require minimum rotation or manipulation of the distal tip.
Inflation of the cuff of the COPA, in theory, widens collapsed pharyngeal structures, leading to a better chance of producing a patent airway; and it may be useful when ventilation through a face mask alone is difficult. However, the COPA may not be ideal in the difficult airway because the seal in the upper pharynx is not always tight, airway manipulation by an assistant may still be required, and visualization of the larynx during fiberscopy may be more difficult because the midline approach is not possible.
Anil Patel, F.R.C.A.
Adrian Pearce, M.R.C.P., F.R.C.A.
Consultant; Department of Anaesthesia, Guy's Hospital; London SE1 9RT, United Kingdom;email@example.com
(Accepted for publication November 17, 1998.)