A sudden collapse and unresponsiveness often signals a life-threatening medical emergency, such as sudden cardiac arrest. In these moments, immediate and informed action is the single most important factor determining a person’s chance of survival. Brain damage can occur within minutes without oxygen-rich blood flow, which is why a rapid, systematic response from a bystander is valuable. This guide provides a clear, step-by-step procedure for a bystander to follow.
Prioritizing Scene Safety and Assessing the Victim
The very first action upon witnessing a collapse is to ensure the safety of both yourself and the victim by quickly scanning the environment for potential hazards. Look for immediate dangers such as oncoming traffic, downed electrical wires, or unstable structures. If the scene is unsafe, the person must be moved to a safer location before any further steps are taken.
Once the area is secure, assess the victim for responsiveness by firmly tapping their shoulder and shouting loudly, “Are you okay?”. If there is no reaction, they are considered unresponsive, and time becomes a critical factor. Check for normal breathing by looking for chest rise and fall for no more than 10 seconds. Occasional, irregular gasps are not considered normal breathing and should be treated as a sign of cardiac arrest.
If the person is unresponsive and not breathing normally, the sequence of immediate action must move to calling for professional help. If a possible neck or spine injury is suspected, minimize moving the person as much as possible while still prioritizing the airway and breathing assessment.
Activating Emergency Medical Services (EMS)
Once unresponsiveness and abnormal breathing are confirmed, immediately activate the local emergency medical services (EMS) by calling 911 or the equivalent emergency number. If other people are present, point directly to one person and instruct them to make the call and return to relay the information. This direct assignment prevents confusion and ensures the call is placed without delay.
The dispatcher is a trained professional who will guide you through the process, so it is important to speak clearly and remain calm. Provide the exact location of the victim, including the street address, nearest cross streets, and any specific details that will help responders find the scene quickly, such as floor number or landmarks. Crucially, state that you have an unresponsive adult who is not breathing normally.
The dispatcher may provide instructions for beginning hands-only cardiopulmonary resuscitation (CPR) or locating an automated external defibrillator (AED). If possible, remain on the line with the dispatcher while initiating care, as they can continue to provide guidance and support.
Initiating Life Support Measures
If the person is unresponsive and not breathing normally, immediate chest compressions must begin to circulate blood, which is the most important component of life support for sudden cardiac arrest. Place the heel of one hand in the center of the person’s chest, right between the nipples, and place the other hand on top, interlacing the fingers. Position your body so your shoulders are directly over your hands, keeping your elbows straight, to use your body weight for compressions.
The compressions must be hard and fast, pushing straight down to a depth of at least 2 inches, but no more than 2.4 inches, on an adult. The rate of compressions should be between 100 and 120 compressions per minute, which is approximately the rhythm of the song “Stayin’ Alive”. Allow the chest to fully recoil to its normal position after each compression, which allows the heart to refill with blood.
If an AED is available, immediately power it on and follow the voice prompts, as early defibrillation significantly increases the chances of survival. The AED will analyze the heart rhythm and advise if an electrical shock is needed. Continue uninterrupted chest compressions until the AED is ready to deliver a shock, or until EMS professionals arrive and take over. Hands-only CPR—continuous chest compressions—is recommended for bystanders who are not trained or are unwilling to perform rescue breaths.
Ongoing Care While Awaiting Arrival of Professionals
Once chest compressions or defibrillation is underway, the focus shifts to maintaining the effort and managing the scene until EMS arrives. Continue high-quality chest compressions without interruption, minimizing any pauses. If there are multiple bystanders, rotate the person performing compressions every two minutes to prevent fatigue, which can decrease the quality and depth of the compressions.
If the victim regains consciousness or begins breathing normally, the compressions should stop, and the person should be placed in the recovery position. The recovery position, a stable side-lying posture, helps keep the airway open and prevents them from choking on their tongue or on stomach contents. To do this, roll the person onto their side, ensuring their head is tilted back slightly to maintain an open airway, and bend their upper leg to stabilize the position.
While waiting, continue to monitor the victim for any changes in responsiveness and breathing, and be ready to resume compressions if they stop breathing normally again. Upon arrival of the EMS team, communicate the sequence of events clearly, including the estimated time of collapse and the interventions performed, such as the duration of CPR and any AED use. Clearing the immediate area for the arriving paramedics will allow them quick access to the victim to take over advanced life support.