Final answer:
In the event of a cardiac arrest with more than 5 minutes elapsed without CPR, perform CPR immediately and use an AED if available, continuing until medical help arrives or the patient recovers.
Step-by-step explanation:
If a patient has been in cardiac arrest for more than 5 minutes and no CPR has been done, the correct course of action is to perform CPR immediately. Cardiac arrest is a critical condition where the heart stops pumping blood effectively, and vital organs, including the brain, do not receive the oxygen they need. Without immediate intervention, permanent brain damage or death can occur. CPR, or cardiopulmonary resuscitation, is a life-saving technique that can manually pump blood through the heart and into the body's circulation, particularly to the brain. Properly executed CPR compresses the chest at least 5 cm deep at a rate of 100 compressions per minute, a rhythm famously matched to the song "Staying Alive." While performing CPR, if available, use an automated external defibrillator (AED) to deliver a shock and restore normal heart rhythm. It is crucial to continue CPR until medical assistance arrives or until the patient shows signs of life.