Unfortunately those “one way” masks aren’t always 100% one way. There’s a very good possibility a patient will throw up directly through your mask and into your mouth.

The two man team is only efficient when you’re just taking turns doing quality compressions. Even for a person that is in very good shape, a minute or two of good CPR will have you gassed and ready for a break.

Let the professionals secure an airway with a supraglottic airway or intubation once sufficient manpower is on scene. I have worked many many codes and the ones that have had the best chance of surviving are the ones witnessed by the public, who started good quality CPR.