A great discussion on pre-oxygenation in the ED and pre-hospital environments, from the PHARM podcast.
Check out the show notes and references here.
A BVM (with PEEP valve) will provide better pre-oxygenation than a NRBM (non-rebreather) AS LONG AS THERE IS A GOOD SEAL.
Adding nasal cannulae may worsen pre-oxygenation a little, likely more than offset by the additional benefit of apnoeic oxygenation.
For me, the problem with a BVM is that the airway practitioner isn’t solely focused on achieving a good seal during pre-oxygenation. They’re doing other things – prepping the eam/patient/equipment etc. Therefore, I’d suggest NRBM and NPs as routine, especially for more inexperienced practitioners. If using a BVM (with PEEP valve), the airway practitioners sole focus needs to be on maintaining a seal.
Also, remember to sit the patient up and use CPAP if necessary.