Time to reconsider the pre-oxygenation during induction of anaesthesia.

Atelectasis is a frequent finding in paralysed and mechanically ventilated patients. Atelectasis, causing shunt, impairs oxygenation and could contribute to postoperative pulmonary complications. Pre-oxygenation used during anaesthesia induction causes atelectasis. A lowering of oxygen fraction from 100% to 80% does not shorten the safety time of apnoea period, particularly useful for a difficult intubation, but it reduces drastically the atelectasis incidence.