When an adult collapses and is unresponsive, immediate action is necessary. The sudden lack of consciousness often indicates cardiac arrest, where the heart has stopped pumping blood effectively. Cardiopulmonary Resuscitation (CPR) is the only immediate intervention capable of maintaining a minimal flow of oxygen-rich blood to the brain and other organs. Survival depends on the speed and precision of the rescuer’s response, which must follow a standardized series of steps.
Activating Emergency Services and Assessing Vitals
The first action upon confirming unresponsiveness is to activate the emergency system. A lone rescuer should immediately call 911 or the local emergency number and place the phone on speaker mode. If others are present, the rescuer should delegate someone to call for help and retrieve an Automated External Defibrillator (AED) if one is nearby.
After activating the emergency system, the rescuer must quickly assess the individual for breathing and circulation within a maximum of 5 to 10 seconds. Look for normal chest movement or listen for breath sounds, but do not waste time searching for a pulse, as lay rescuers often struggle to locate it accurately. If the person is not breathing normally, or is only gasping (agonal breathing), this indicates cardiac arrest and requires the immediate initiation of CPR. Agonal breathing is not effective and should be treated as no breathing at all.
Delivering High-Quality Chest Compressions
Chest compressions are the primary component of CPR because they manually circulate blood the heart can no longer pump. The individual must be placed on their back on a firm, flat surface to maximize effectiveness. The rescuer should kneel beside the person and position the heel of one hand on the center of the chest, over the lower half of the breastbone, placing the second hand directly on top with fingers interlaced.
Proper body mechanics are necessary to achieve the required depth and rate of compression. The rescuer should position their shoulders directly over their hands, keeping their arms straight and elbows locked, using their upper body weight to push down. The pressure must compress the chest to a depth of at least 2 inches, but not exceeding 2.4 inches, at a rate between 100 to 120 per minute.
Allowing the chest to fully recoil between each compression is also important, as this permits blood to flow back into the heart chambers. The rescuer should avoid leaning on the chest during the relaxation phase. Minimizing interruptions to compressions is paramount, with pauses limited to less than 10 seconds. If a lay rescuer is untrained or unwilling to perform rescue breaths, compression-only CPR is supported.
Integrating Airway Management and Rescue Breaths
For a trained rescuer willing to provide breaths, the sequence involves alternating chest compressions with ventilation. After delivering 30 compressions, the rescuer should open the airway using the head-tilt, chin-lift maneuver. This technique involves placing one hand on the forehead and gently tilting the head backward while using the fingers of the other hand to lift the bony part of the chin. This maneuver lifts the tongue away from the back of the throat, preventing airway blockage.
Once the airway is opened, the rescuer should pinch the nose closed and cover the mouth completely to create an airtight seal. Two rescue breaths should then be delivered, each lasting about one second, confirming that the chest visibly rises. If the chest does not rise after the first breath, the rescuer must quickly reposition the head before attempting the second breath. The 30 compressions to 2 breaths ratio is maintained until the AED arrives or emergency medical services take over.
The inclusion of rescue breaths is especially important when the cause of arrest is likely asphyxia, such as drowning or drug overdose.
When the AED Arrives
The arrival of an Automated External Defibrillator (AED) is the next major step, as it can correct certain life-threatening heart rhythms. The rescuer should stop compressions only long enough to power on the AED and follow the voice prompts, which instruct them to expose the chest and apply the electrode pads.
For an adult, the standard anterolateral placement is used: one pad is positioned on the upper right side of the chest, just below the collarbone, and the second pad is placed on the lower left side, typically below the left armpit. After the pads are connected, the AED will prompt the rescuer to stand clear while it analyzes the heart’s electrical rhythm.
If a shockable rhythm is detected, the device will charge and advise a shock. The rescuer must ensure no one is touching the person before pushing the shock button. Immediately after the shock is delivered, or if the AED advises “no shock advised,” the rescuer must immediately resume chest compressions until professional medical help arrives.