Intervention
Thirty participants were sequentially allocated in blocks of 3 to the biofeedback (n=10), nose analogy (n=10) and syringe (n=10) teaching methods. Participants were provided with written instructions for their allocated method (Figure 2) and afforded as much time as they deemed necessary to practise the method.
For the biofeedback method, participants were able to directly read the force values on the measuring scales when pressing on the airway model and therefore used real-time feedback to apply the recommended cricoid pressure force for “awake” and “anaesthetised” patients. For the nose method, participants were not given access to the airway model. They were given written instructions which advised that for “anaesthetised” patients a pressure on the nose to cause significant pain should be applied. Participants then practised pressing on their own nose to feel the force required. There were no teaching instructions given for “awake” patients, since this is not provided in the literature[7]. The syringe method consisted of a 50ml closed syringe enclosed in a wooden box with a 50ml syringe attached to the plunger (Figure 3). Compression of the enclosed syringe to 38ml is reported to be equivalent to the recommended pressure for “awake” patients and compression of enclosed syringe to 30ml is reported to be equivalent to the recommended pressure for “anaesthetised” patients[8].