Two randomized, controlled, cross-over trials (RCTs) using Basic Life Support (BLS) airway providers, defined as inexperienced users (IU’s), with annually trained Guedel airway and Facemask skills, compared ventilation using either the Tulip airway or a Guedel airway with Facemask in 60 subjects, first in manikins and then in humans after the induction of anaesthesia, using identical protocols but within the limitations of equipment that prevented the estimation of end expiratory CO2 in manikins (see Table 1).