You’re rotating in the RICU and while there one of your patients develops respiratory distress requiring intubation. As you are preparing your equipment you notice that the intern on the team, who is trying to be helpful, is holding the BVM above the patients face to provide, “blow by oxygen.” Why is this not a beneficial preoxygenation strategy?

A BVM provides an FiO2 approximately equal to room air.  The valve in the BVM prevents a greater flow of oxygen from being delivered unless you are actively squeezing the bag.  Instead of using the BVM try preoxygenating your patient with a nasal cannula and non-rebreather, or high flow NC if it’s available at your shop.  This will provide oxygen in the range of 40-60 L/min, which provides nearly 100% O2.  Using the NC and NRB allows you to leave the NC on while you intubate too.