This type of situation is exactly the reason AEDs are now found all over in public places. Sure, CPR for several hours does not yield positive outcomes. But if this guy is slumped because of a shockable rhythm, that AED in the field is not at all useless - it will likely save his life, and minimize the deficits he experiences afterward. Especially on a plane, where the person was likely noticed down minutes after his problem started.
