In emergency situations, quickly determining if an individual is alive and responsive is the first step in providing life-saving assistance. For a layperson, the goal is to assess the need for immediate medical intervention, not to formally pronounce life or death. Acting quickly and following a systematic assessment sequence significantly increases the chance of a positive outcome for someone who is unresponsive. This process begins by ensuring the environment is safe before checking for consciousness.
Initial Steps to Determine Consciousness
The initial approach to an unresponsive person must prioritize personal safety by quickly scanning the environment for hazards such as traffic, fire, or downed power lines. Once the scene is safe, the priority shifts to checking the individual’s level of consciousness. A simple and effective method is the “Shake and Shout” technique, which involves gently tapping the person’s shoulder while speaking loudly, asking if they are okay.
This verbal and physical stimulation attempts to elicit a response, such as a movement, groan, or spoken word. If the person responds in any way—even a slight purposeful movement—they are considered conscious and do not require immediate cardiopulmonary resuscitation (CPR). If there is no response, the person is unresponsive, and the next step is to assess for breathing and circulation.
Checking for Breathing and Circulation
Once unresponsiveness is confirmed, the immediate action is to check for signs of normal breathing and circulation. Rescuers should open the airway using the head-tilt, chin-lift maneuver, which moves the tongue away from the back of the throat. With the airway open, the rescuer must visually look for the rise and fall of the chest, listen for breath sounds, and feel for air movement on their cheek.
This assessment for normal breathing must be completed in no more than 10 seconds. Occasional gasps or slow, labored, or noisy breathing, known as agonal respirations, should not be mistaken for normal breathing. These are often a sign of cardiac arrest and necessitate immediate intervention.
A layperson should also attempt to check for a pulse, specifically the carotid pulse, which is the most reliable location for a quick check. To locate the carotid pulse, two fingers should be placed on the side of the neck, in the groove between the windpipe and the large muscle. Use the index and middle fingers, not the thumb, and check only one side of the neck at a time to maintain blood flow to the brain. Like the breathing check, this pulse check should take no longer than 10 seconds, and if there is any doubt about the presence of a pulse or normal breathing, CPR should be initiated immediately.
When to Call for Help and Initiate CPR
The sequence of calling for emergency services and beginning CPR, known as “Call First” or “Care First,” depends on the person’s age and the suspected cause of the collapse. For an adult who collapses suddenly, the recommended protocol is “Call First.” The rescuer should call the local emergency number immediately before starting CPR because adult cardiac arrests are most often caused by a heart problem, where immediate defibrillation is the most effective treatment.
For a child or a victim whose arrest is likely due to a lack of oxygen (such as from drowning or a blocked airway), the “Care First” approach is advised. A single rescuer should perform two minutes or five cycles of CPR before pausing to call emergency services. This acknowledges that children are more likely to respond to initial rescue breathing and compressions because their arrests are often respiratory in origin. If two or more rescuers are present, one should immediately call for help and retrieve an automated external defibrillator (AED) while the other begins chest compressions.
Irreversible Signs of Clinical Death
While a layperson focuses on intervention, certain physical changes indicate that biological death has occurred and is irreversible. These post-mortem changes are not part of the initial emergency assessment but are recognized signs that intervention would be futile. Rigor mortis, the stiffening of the body’s muscles, typically begins within two to four hours after death and becomes complete around 12 hours.
Another sign is livor mortis, or lividity, which is the pooling of blood in the dependent parts of the body due to gravity. This discoloration begins to appear within 30 minutes to two hours after death. It becomes fixed, meaning it will not blanch or shift when pressed, approximately eight to twelve hours later. Signs of decomposition, such as putrefaction or the breakdown of tissue, confirm death and begin to appear in the later stages, often after 24 to 72 hours. These definitive signs confirm the absence of life, indicating a time frame well beyond the window for successful resuscitation.