Introduction: We studied a new rescue breathing device consisting of a mouthcap and a "glossopalatinal" tube reaching between tongue and palate (the "GPT"), with a connector for a bag, ventilator or rescuers mouth. By tilting the connector in a cranial direction, the tongue can be "scooped" out of the hypopharynx. The study was to test the efficacy and the ease of application of the GPT in anaesthetised patients. It was compared with a conventional face mask with and without an oropharyngeal (OP) airway.
Methods: 19 patients (ethics committee approval, informed consent) anaesthetised for elective surgery were ventilated using an anaesthesia circuit and Ventilog (Draeger) through the GPT and via a face mask (Laerdal) with and without an OP tube. Flow and pressures at the airway opening, in the hypopharynx and the trachea were measured, and the resistance was derived. In addition, the relations of the devices to the anatomical structures were visualised by fibrescope, and ease of operation and fit on the face were scored.
Results and conclusions: Inspiratory resistance with the GPT and mask did not differ (1.31+/-0.96 vs. 1.38+/-0.66 kPa s/l at 1 l/s, mean+/-standard deviation (S.D.); reduction of resistance by "scooping" the tongue through angulation of the GPT (to 0.64+/-0.32; P<0.05 vs. GPT without angulation) was equivalent to that by an OP tube used with the mask (to 0.68+/-0.26; P<0.05 vs. mask solo). Pharyngoscopy showed that the effectiveness of the GPT depended on the individual anatomy. The angulating motion caused some fatigue. The GPT is an alternative to established breathing adjuncts; despite not protruding into the pharynx it can enhance airway patency like an OP.