Safety implications of the Boyle-Davis mouth gag and tracheal tube position in tonsillectomy.

BACKGROUND

The risk of death after tonsillectomy is extremely small, and is mostly caused by the direct or indirect effects of haemorrhage or anaesthetic complications. These complications include aspiration, accidental dislodgement of the tracheal tube (TT), and pneumothorax or pneumomediastinum. The Boyle-Davis mouth gag (BDG) is a device used to visualize the oropharynx and stabilize the TT during tonsillectomy. We postulate that a deployed BDG may influence the position of the TT, and potentially result in silent aspiration, accidental extubation, and unilateral pulmonary ventilation. This has not, to our knowledge, been evaluated before. The aim of this prospective, pilot study was to evaluate the displacement of the TT upon opening and closing the BDG, in an objective manner.

METHODS

Patients undergoing tonsillectomy with/without adenoidectomy at a regional department underwent flexible bronchoscopy to evaluate the changes in position of the TT tip with the BDG in an open and closed position, relative to the position of the carina.

RESULTS

Twenty-three patients were enrolled into the study. Deploying the BDG resulted in TT displacement in 96% of patients. The mean displacement was 9.5 mm (range -10 to +27 mm).

CONCLUSIONS

We believe that this study raises concerns not previously highlighted, on how manipulating a BDG may influence the TT position. It may serve to explain additional mechanisms of potentially fatal anaesthetic complications such as TT dislodgement, unilateral ventilation, and pneumothorax, particularly in paediatric patients, after tonsillectomy.