Final answer:
CPR should be initiated after 2 minutes of rescue breathing if the infant or child is still not responding. It's essential to start CPR as soon as possible for a higher chance of recovery. However, in cases of cold water immersion, attempts at resuscitation may be successful even after longer periods.
Step-by-step explanation:
When providing rescue breathing to an infant or child, CPR should be initiated after 2 minutes of rescue breathing if the child is still not breathing normally, coughing, or showing signs of life. The reason behind this timeframe is that the sooner CPR is started after a person stops breathing, the better their chances of survival, particularly if the airway was protected from water entering the lungs.
It is worth noting that rescuers retrieving a child from cold water should attempt resuscitation even after a protracted period of immersion since children have been known to survive longer periods in cold water without brain damage. Overall, initiating CPR in a timely manner is critical, and one should always follow the latest guidelines provided by recognized authorities such as the American Heart Association.