When a person suddenly collapses and is unresponsive, the heart has ceased to pump blood effectively, a condition known as cardiac arrest. This is fundamentally an electrical problem within the heart, where the normal rhythm is replaced by chaotic electrical activity, or sometimes none at all. Cardiac arrest differs from a heart attack, which is a plumbing problem where a blockage stops blood flow to a section of the heart muscle. A heart attack can sometimes trigger cardiac arrest. Immediate action is necessary, as the chance of survival decreases every minute that passes without intervention.
Activating Emergency Services and Retrieving an AED
When a person is found unresponsive and not breathing normally, the first action must be to engage the emergency response system. If a second person is present, one rescuer should immediately begin chest compressions while the other calls 911 or the local emergency number. Providing the dispatcher with the precise location and stating clearly that an adult male is in cardiac arrest and CPR is in progress ensures a rapid and appropriate response.
The person making the call must also ask the dispatcher about the location of the nearest Automated External Defibrillator (AED). These devices deliver an electric shock to reset the heart’s rhythm and are common in public spaces like offices, gyms, and airports. Early defibrillation is a significant link in the Chain of Survival for improving outcomes in sudden cardiac arrest.
The rescuer retrieving the AED must move quickly, as every minute of delay reduces the chance of survival by roughly 10%. If the caller must leave the patient, they should be instructed by the dispatcher to keep the phone on speaker mode. This allows the dispatcher to provide continuous, real-time instructions and support until the AED arrives at the scene.
Maintaining Effective Chest Compressions
While awaiting the AED and professional help, the priority is maintaining high-quality blood circulation through chest compressions. The goal is to manually pump oxygenated blood to the brain and other vital organs to limit cellular damage. The compression rate must be fast, aiming for a tempo of 100 to 120 compressions per minute.
The physical technique requires pressing down hard in the center of the chest, specifically on the lower half of the breastbone. For an adult, the compression depth must be at least two inches (five centimeters), but should not exceed 2.4 inches (six centimeters). It is important to allow the chest to fully recoil after each compression, which permits the heart to refill with blood.
Minimizing interruptions to compressions is a major focus of modern resuscitation guidelines, as pauses disrupt blood flow to the brain. If the rescuer is trained in cardiopulmonary resuscitation (CPR) with breaths, the standard ratio is 30 compressions followed by two rescue breaths. If a person is untrained or unwilling to give breaths, hands-only CPR, which involves continuous chest compressions, is an acceptable intervention.
Operating the Automated External Defibrillator
Defibrillation treats ventricular fibrillation, the most common cause of sudden cardiac arrest. Using the AED is a straightforward process guided by voice prompts. The first step upon arrival is to power on the AED and follow the machine’s instructions immediately.
Once the machine is on, the patient’s chest must be bare and dry to allow the adhesive pads to make good electrical contact. The adult pads should be placed in an anterolateral position: one pad on the upper right side of the chest, above the nipple, and the other pad on the lower left side, below the armpit. These positions ensure the electrical current passes directly through the heart muscle.
The AED will then instruct everyone to stand clear while it analyzes the patient’s heart rhythm. No one must touch the patient during this analysis to prevent inaccurate readings. If the AED determines a shockable rhythm is present, it will advise a shock and begin charging. The rescuer must shout a final warning, such as “Clear!”, before pressing the flashing shock button on semi-automatic models.
Immediately after the shock is delivered, or if the AED advises no shock, the rescuer must resume chest compressions without delay. The AED will continue to provide prompts and reanalyze the rhythm approximately every two minutes. The device remains on and the pads stay attached throughout the resuscitation effort.
Transitioning Care to Emergency Medical Services
The efforts of lay rescuers are designed to bridge the gap between the onset of cardiac arrest and the arrival of Emergency Medical Services (EMS). When paramedics arrive, the priority is a smooth and effective transfer of care. The rescuer should continue with high-quality CPR until an EMS provider specifically directs them to stop and take over.
Once care is transferred, the bystander rescuer should immediately provide a concise report to the EMS team. This report should detail when the patient collapsed, when CPR was initiated, the number of shocks delivered by the AED, and the time of the last shock. This information is important for the advanced life support team to make immediate, informed decisions about further treatment.
For a 40-year-old man, sudden cardiac arrest often indicates an underlying, previously undiagnosed condition, such as hypertrophic cardiomyopathy or an electrical abnormality. Post-resuscitation care, which begins once the patient is stabilized, focuses on addressing the cause of the arrest and managing potential brain and organ injury. Rescuers should step back after the transition but remain available to answer any further questions from the medical team.