The most sobering concept I encountered in CERT training was the triage protocol- if the victim's airway is occluded, make two attempts to open it. If unsuccessful, drop a black tag and move on. Do not attempt CPR in the overwhelming disaster to which this protocol applies. Think about it a bit - it makes perfect sense. Our instructor pointed out that CPR requires massive application of resources for what is typically an unsuccessful outcome. He stated that he had been present at something like 300 CPR scenes, and had witnessed or participated in exactly seven successful resuscitations.