Final answer:
The compression to ventilation ratio for CPR given by a single rescuer is 30:2 for all ages, focusing on high-quality chest compressions at a correct rate and depth, with proper training being essential for effectiveness.
Step-by-step explanation:
The compression to ventilation ratio for one rescuer giving CPR to individuals of any age is 30:2, which means 30 chest compressions followed by two ventilations. This ratio is the same for adults, children, and infants, with the exception of newborns. Proper chest compressions involve applying pressure with the flat portion of one hand on the sternum between the T4 and T9 vertebrae and compressing the chest at least 5 cm deep at a rate of 100 compressions per minute. Performing high-quality chest compressions is currently emphasized over providing artificial respiration, which is significant for ensuring blood flow to the brain. Even in emergencies such as an unconscious person rescued from drowning, CPR's effectiveness relies heavily on the speed and accuracy of its administration, and proper training and certification are strongly recommended.