Airway management with the Combitube during anaesthesia and in an emergency

The oesophageal-tracheal Combitube (Kendall-Sheridan Catheter Corp., Argyle, NY) is a device designed for difficult airways and emergency intubation. The manufacturer recommends that the Combitube size 37F SA be used in patients with a height of between 122 and 152 cm. The aim of this study was to evaluate whether ventilation is effective and reliable in anaesthetized patients taller than 152 cm using the size 37F SA in the oesophageal position. We also evaluated whether airway protection is adequate and whether direct intubation of the trachea with the Combitube inserted in the oesophagus is possible. We studied 15 adult patients undergoing routine general anaesthesia and 20 patients who required emergency intubation following trauma. They were between 150 and 180 cm in height. Under direct vision, a size 37F SA Combitube was inserted into the oesophagus of all the patients undergoing routine general anaesthesia (control group). Blind insertion was performed in the emergency patients (emergency group). The pharyngeal balloon was inflated with a volume titrated to air leak and cuff pressures were measured. During surgery, a laryngoscope was inserted into the pharynx with the pharyngeal balloon deflated and the laryngoscopic view was evaluated using the Cormack-Lehane scale. Ventilation was effective and reliable in all 35 patients who were between 150 and 180 cm in height. In addition, a direct relationship between the pharyngeal balloon volume and patient height was established (P<0.05), using linear regression models. The laryngoscopic view of the glottis was adequate to allow direct tracheal intubation in patients in the control group, so that the Combitube size 37F SA may be used in patients from 122 to 185 cm in height. The trachea could be directly intubated with the Combitube in the oesophageal position in patients with normal airways and in patients involved in trauma. In all patients in the emergency group, blind insertion of the Combitube resulted in the device being placed in the oesophagus. The airway protection appears to be adequate.