Apnoeic oxygenation is a concept introduced by Scott Weingart to minimize the risk of critical hypoxia during emergency tracheal intubation.
This is the summary of how you should do it:
And if you have time to read the whole article, it is highly recommended.
If people have got time another great article by Scott covers the principles of DSI (delayed sequence intubation) and can be found at http://traffic.libsyn.com/emcrit/preox_reox_article.pdf