An assessment of protection of the airway from aspiration of oropharyngeal contents using the Combitube airway.

A Combitube airway was inserted blindly into 27 American Society of Anaesthesiologist (ASA) grade 1 and 2 patients undergoing general anaesthesia. All had Cormack and Lehane grade 1 direct views of the larynx. Ten ml of 0.1% methylene blue dye was instilled into each patients mouth for the duration of surgery. The oropharynx was then aspirated and dried at completion of surgery and the Combitube removed. The laryngeal inlet and trachea were examined for dye staining. In 25/27 patients (93%) no tracheal soiling was seen. In 2/27 patients (7%) tracheal soiling was seen (95% confidence interval 0.9-24.3%). The Combitube protects the airway in the majority of patients from aspiration of dye within the oral cavity, but the failure rate means it cannot be relied upon absolutely to do so. This has implications for management of the trauma patient.