Cardiopulmonary Resuscitation (CPR) is an emergency procedure performed when a person’s heart stops beating or they are not breathing normally. The procedure combines chest compressions and rescue breathing to manually circulate blood and oxygen to the brain and vital organs until advanced medical help can take over. Because time is a limiting factor in cardiac emergencies, a structured framework guides the initial response. This framework, known as the 3 C’s, provides a systematic path for anyone to follow in the first moments of an emergency.
The First C: Checking the Scene and Victim
The first step in any emergency is to confirm the safety of the environment before approaching the person in need. A rescuer must quickly scan the area for potential dangers, such as electrical wires, active traffic, unstable structures, or fire, which could endanger themselves or the victim. Entering an unsafe scene risks turning one victim into two, delaying the entire emergency response.
Once the scene is safe, the rescuer must immediately check the victim for responsiveness. This is typically done by gently tapping the person and loudly asking, “Are you okay?” An unresponsive person does not move, speak, blink, or otherwise react to these attempts.
Next, the rescuer should quickly check for normal breathing. An adult who is not breathing normally or is only gasping is considered to be in cardiac arrest. This rapid assessment dictates the immediate need to activate the emergency medical services (EMS) system.
The Second C: Calling for Help
Activating professional help is the immediate next step after confirming the scene is safe and the victim is unresponsive and not breathing normally. The priority is to call the local emergency number, or have a bystander make the call, before initiating care. Getting the Emergency Medical Services (EMS) en route quickly is paramount, as only they can provide the definitive care needed to reverse a cardiac arrest.
The caller should be prepared to give the dispatcher precise details about the location of the emergency to minimize arrival time. This includes the street address, cross streets, and any building or apartment numbers. It is also important to clearly state the nature of the emergency, such as “an adult collapsed and is not breathing,” and to accurately relay the victim’s status.
The dispatcher may also instruct the caller to look for an Automated External Defibrillator (AED) and to retrieve it if one is visibly nearby. These devices can deliver an electrical shock to restart the heart, and their use, alongside early CPR, significantly increases the chance of survival. The dispatcher will often provide guidance on locating the AED and beginning immediate care.
The Third C: Providing Immediate Care
The third C, providing immediate care, involves performing physical actions to sustain the person’s life until professional help arrives. For a lay rescuer responding to an adult who has suddenly collapsed, this means initiating high-quality chest compressions, often referred to as Hands-Only CPR. The goal of these compressions is to manually pump blood from the heart to the rest of the body.
The rescuer should position the victim on a firm, flat surface. Place the heel of one hand on the center of the person’s chest, right between the nipples. The other hand is placed on top, fingers interlaced, with the elbows locked and shoulders directly over the hands. Compressions must be delivered forcefully, pushing down at least 2 inches, but no more than 2.4 inches, for an average adult.
Compressions must be performed at a rapid rate, between 100 to 120 compressions per minute. A helpful mnemonic for maintaining this tempo is to compress to the beat of songs like “Stayin’ Alive.” It is equally important to allow the chest to fully recoil after each compression, permitting the heart to refill with blood before the next push. Conventional CPR involves alternating 30 compressions with two rescue breaths, though Hands-Only CPR is the recommended approach for the general public.
What Happens After the Initial Sequence
After checking the victim and calling for help, the rescuer must continue to provide care without interruption until specific conditions are met. Sustained, continuous chest compressions are physically demanding, and the rescuer should continue the effort until professional medical responders arrive to take over. If a second person is present, they should take turns performing compressions to prevent fatigue and maintain the quality of the action.
The rescuer should stop compressions if an AED becomes available and is ready to analyze the heart rhythm or deliver a shock. Following the voice prompts of the AED takes precedence over continuing manual compressions. The rescuer can also stop if the person shows obvious signs of life, such as purposeful movement, or if the scene suddenly becomes unsafe again, requiring the rescuer to retreat.