Cardiopulmonary Resuscitation (CPR) is an emergency procedure that maintains blood circulation and oxygen supply during cardiac arrest. The immediate goal of CPR is to sustain the brain and other organs until the heart can be restarted or advanced medical care arrives. When applied to an unresponsive adult, this procedure follows standardized guidelines tailored to maximize the chance of a positive outcome.
Initial Assessment and Activating Emergency Services
The first step is ensuring the environment is safe for both the victim and the rescuer. Once safety is confirmed, the rescuer must assess the unresponsive individual by tapping their shoulder and shouting, “Are you okay?”. If the person does not respond, a bystander should immediately be directed to activate the emergency response system (e.g., 9-1-1) and to retrieve an Automated External Defibrillator (AED) if one is available nearby.
The rescuer should then check for normal breathing and a pulse simultaneously, taking no more than 10 seconds. For lay rescuers, the absence of normal breathing or the presence of only gasping signals the need to begin compressions. Activating emergency services is the priority immediately following the determination of unresponsiveness. This “Call, Push, Shock” sequence emphasizes that for an adult victim who suddenly collapses, the immediate priority is to get help on the way and start chest compressions.
Performing the CPR Cycle: Compressions and Breaths
Adult CPR follows the C-A-B sequence: Compressions, Airway, and Breathing. Chest compressions are the most important part of the cycle for an adult in cardiac arrest because the need is to circulate the oxygenated blood already in the body. High-quality compressions require the rescuer to place the heel of one hand in the center of the chest, on the lower half of the breastbone, and place the other hand on top.
Compressions must be delivered at a rate between 100 and 120 pushes per minute. The depth should be at least two inches, but must not exceed 2.4 inches. Allowing the chest to fully recoil after each compression is important, as this permits the heart to refill with blood before the next pump.
After 30 compressions, the rescuer should open the airway using the head-tilt/chin-lift maneuver. This technique positions the head to allow air to pass into the lungs. Two rescue breaths are then administered, each lasting about one second, aiming for the chest to visibly rise. The 30:2 cycle should be continued without interruption until the AED is ready or emergency medical services take over.
Integrating the Automated External Defibrillator
The Automated External Defibrillator (AED) should be used as soon as it becomes available to deliver an electrical shock to a heart in abnormal rhythms. The first action upon receiving the AED is to power it on and follow the device’s voice prompts. The adult pads are applied to the bare chest, typically with one pad placed on the upper right side of the chest and the other on the lower left side, below the armpit.
Once the pads are connected, the AED will analyze the heart’s rhythm; no one should touch the victim during this analysis. If the AED determines a shockable rhythm is present, it will charge and instruct the rescuer to deliver the shock. Immediately after the shock is delivered, or if the AED advises that no shock is needed, the rescuer must promptly resume chest compressions, starting the 30:2 cycle again. This pattern of CPR and AED analysis should continue, with compressions resumed immediately after any AED action, until the arrival of advanced life support personnel.