Apnoeic oxygenation in anaesthesia is the concept of providing oxygenation without ventilation. The idea is that even without lung expansion, oxygen will passively be dragged into the alveoli along the oxygen gradient caused by alveolar oxygen being transported away by the bloodstream. Hope that makes sense. If not, theres a better explanation at LITFL. In theory, and in experimental conditions, the apnoeic patient will remain oxygenated indefinitely, given that the FiO2 in the pharynx is high enough and given that the airway is perfectly patent. The problem is rather hypercapnia and acidosis building up.
Since a few years, apnoeic oxygenation has been incorporated into emergency anaesthesia and intubations. If we could provide apnoeic oxygenation during laryngoscopy, then we would have all the time in the world to intubate as the patient won’t deoxygenate. Most systems I am aware of have applied nasal cannula with high flow O2. I was concerned about that. Can we really achieve an high enough FiO2 in the pharynx with just nasal cannulae? Also, many of the patients I intubate have facial and nasal bleeds or injury which should restrict oxygen flow.
So I was a bit intrigued by a solution that was recently posted on youtube. It´s the (Royal, Imperial???) Hungarian HEMS demonstrating their RSI protocol. Note how they pre-oxygenate with a non-rebreather mask and two nasal airways. Then, at 1:00, after relaxation, instead of using nasal cannulae for apnoeic oxygenation, they cut the oxygen tubing and shove it way down the nasal airway. This way, they provide high O2 flow, and apnoeic oxygenation, directly at the oropharynx. At least, I think that is what is going on. I don´t understand a word of what they’re saying.