To clarify...
2 "Rescue Breaths" per 30 compressions technically. BUT USA has adopted 0 breaths and their revival rate went up to nearly 100%.
Ours was 3% until they changed it to 2 Rescue breaths and it's now 30% or so. My personal preference is now 0 breaths. The compressions draw in sufficient air to oxygenate the small amount of blood that gets pumped anyway.
I have to do my CPR and Switchboard Resuce every 6 months
