The initial assessment of an unresponsive person is a time-sensitive step in any emergency, determining whether immediate cardiopulmonary resuscitation (CPR) is necessary. The primary purpose of a pulse check is to determine if the person’s circulatory system is moving blood effectively enough to sustain life. Determining the presence or absence of a pulse is a prerequisite for beginning chest compressions, making this initial check a foundational component of basic life support. A swift assessment is required to avoid delaying life-saving measures if circulation has stopped.
The Critical Time Window
Standard emergency protocols dictate that a pulse check must last no less than five seconds but no more than ten seconds. This narrow window balances accuracy with the urgent need to start compressions if the heart is not pumping. Checking for less than five seconds risks missing a weak pulse, potentially leading to unnecessary chest compressions.
The maximum limit of ten seconds is established because any longer delay significantly reduces the chance of survival if the person is in cardiac arrest. Every second without adequate circulation means less oxygenated blood reaches the brain and vital organs. If the rescuer cannot definitively feel a pulse within this timeframe, chest compressions must begin immediately. This strict time limit minimizes the “hands-off” time, maximizing the effectiveness of the resuscitation effort.
Locating the Pulse
For an unresponsive adult or child, the carotid artery is the preferred and most reliable location for checking the pulse. This artery is easily accessible and typically maintains a detectable pulse even when peripheral pulses have become too faint due to low blood pressure. To check the carotid pulse, the rescuer should use the index and middle fingers to gently palpate the groove on the side of the neck, situated between the windpipe and the large muscle.
Avoid using the thumb for palpation, as it has its own pulse which can confuse the rescuer. For infants (under one year old), the carotid pulse is generally not used due to difficulty in locating it. Instead, the brachial pulse, located on the inside of the upper arm between the elbow and the shoulder, is the recommended site. Gentle pressure is applied with the index and middle fingers, ensuring the check is completed within the five-to-ten-second window.
Immediate Action Following the Check
The result of the ten-second pulse check dictates the next action: starting CPR or providing supportive care. If a pulse is definitely felt within the time limit, chest compressions are not required because the heart is still circulating blood. The rescuer must then immediately assess the person’s breathing.
If the person has a pulse but is not breathing normally or is only gasping, the focus shifts to providing rescue breathing, typically one breath every five to six seconds for an adult. The rescuer continues to monitor the pulse, checking again approximately every two minutes. Conversely, if ten seconds elapse and the rescuer cannot find a pulse or is unsure, the rescuer must immediately begin high-quality chest compressions. This starts the cycle of 30 compressions followed by two rescue breaths.