For CPR or CCR to be effective the patient’s circulatory system must be intact and their core temperature above 90º F (32º C); your chest compressions must be hard and fast (ideally 100 per minute) and delivered in the lower third of the patient’s sternum; your weight must be directly over the patient and the patient’s chest must be allowed to fully recoil between compressions; the recoil is as important as the compression. If rescue breathing is indicated, ventilate until the patient’s chest begins to rise; do not over-inflate — over-inflation forces air into the patient’s stomach and increases the chance or frequency of vomiting.
In settings where rapid defibrillation, advanced cardiac life support, and rapid transport to a major hospital are not possible, the overwhelming majority of patients in cardiac arrest will die. It is important that all rescuers understand the limits of CPR and CCR and when it is appropriate to start and stop.
When teaching chest compressions in our wilderness medicine courses we often tell students to compress at the rate of the beat in the Bee Gee's disco tune "Staying Alive" or Queen's "Another One Bites the Dust" depending on whether a student views the glass as half full or half empty.... Yes, humor is important in the medical field.