The Articulated Oral Airway as an aid to mask ventilation: a prospective, randomized, interventional, non-inferiority study

Abstract

Background Oropharyngeal airways are used both to facilitate airway patency during mask ventilation as well as conduits for flexible scope intubation, though none excel at both. A novel device, the Articulated Oral Airway (AOA), is designed to facilitate flexible scope intubation by active displacement of the tongue. Whether this active tongue displacement also facilitates mask ventilation, thus adding dual functionality, is unknown. This study compared the AOA to the Guedel Oral Airway (GOA) in regards to efficacy of mask ventilation of patients with factors predictive of difficult mask ventilation. The hypothesis was that the AOA would be non-inferior to the GOA in terms of expiratory tidal volumes by a margin of 1 ml/kg, thus demonstrating dual functionality. Methods In this randomized controlled clinical trial, fifty-eight patients with factors predictive of difficult mask ventilation were mask ventilated with both the GOA and the AOA. Video of the anesthetic monitors were evaluated by a blinded member of the research team, noting inspiratory and expiratory tidal volumes and expiratory CO2 waveforms. Results The AOA was found to be non-inferior to the GOA at a margin of 1 ml/kg with a mean weight-standardized expiratory tidal measurement 0.45 ml/kg lower (CI: 0.34–0.57) and inspiratory tidal measurement 0.109 lower (CI: − 0.26-0.04). There was no significant difference in expiratory waveforms (p = 0.2639). Conclusions The AOA was non-inferior to the GOA for mask ventilation of patients with predictors of difficult mask ventilation and there was no significant difference in EtCO2 waveforms between the groups. These results were consistent in the subset of patients who were initially difficult to mask ventilate. Trial registration ClinicalTrials.gov, NCT03144089, May 2017.

A special face mask with integrated angle meter to optimize the head position for bag-valve-mask ventilation—a prospective simulated proof-of-concept study

“…Therefore, the rescuer had to tilt the head for keeping airway in patent state, to seal the face mask onto patient's face, and to push the ventilation bag. It was thus not surprising if this procedure often resulted in the insufficient ventilation by less experienced rescuers, especially in emergency [8,12]. This procedure was further complicated if one of the steps was insufficiently carried out, which in turn might complicate another one and vice versa.…”

“…However, the most experienced anesthesiologists did not know the difficulties and the trainings required for simultaneously tilting the head into correct position, sealing the facemask and providing tidal volumes with a bag valve device [5][6][7]. The proper BVM ventilation could improve its performance particularly for the less experienced rescuers [6,8,9]. A tilted head position to 43 degrees compared to the horizontal plane had been effective in opening the upper airway, as observed in magnetic resonance tomography based studies [10,11].…”