Cardiopulmonary Resuscitation (CPR) is an emergency procedure performed when someone’s heart has stopped beating or they are not breathing effectively. This intervention involves chest compressions and rescue breaths to manually circulate blood and oxygen until professional help arrives. Assessing circulation, primarily by checking for a pulse, is a significant step in this process. Current guidelines establish specific protocols for when and how this check should occur to maximize the effectiveness of these life-saving measures.
Initial Decision: Determining the Need for CPR
The decision to initiate chest compressions depends on whether the person is unresponsive and lacks normal breathing. For a lay rescuer, the guidelines instruct them to skip the pulse check. They should immediately begin chest compressions if the person is unresponsive and not breathing, or only gasping, because attempting to find a pulse often leads to dangerous delays in starting CPR.
This approach prioritizes the immediate delivery of compressions. Untrained rescuers frequently struggle to correctly identify a pulse. The benefit of providing CPR to someone who might not need it outweighs the risk of delaying compressions for someone in cardiac arrest.
Healthcare providers (HCPs) are trained to perform an initial pulse check before starting CPR. After confirming unresponsiveness and absent or abnormal breathing, the HCP should check a pulse for a minimum of 5 seconds but for no more than 10 seconds. If a definitive pulse is not felt within this short window, the HCP must assume cardiac arrest and immediately begin chest compressions.
Standard Reassessment Frequency During CPR
Once chest compressions have begun, the frequency of pulse checking is standardized. For healthcare providers performing CPR, the pulse must be reassessed approximately every two minutes. This interval corresponds to five cycles of 30 compressions and two breaths in a single-rescuer scenario, or a similar period of continuous compressions in a team setting.
The purpose of this regular reassessment is to determine if Return of Spontaneous Circulation (ROSC) has occurred, meaning the person’s own heart has started beating effectively again. If the pulse check is performed as part of an Advanced Cardiac Life Support (ACLS) protocol, it often coincides with a rhythm check using a defibrillator. This allows the medical team to see if the heart’s electrical activity has changed and adjust their treatment plan.
Maintaining continuous, high-quality chest compressions is paramount, as every pause reduces the pressure needed to perfuse the heart and brain. Therefore, the two-minute check is the designated interval where a brief pause is permitted to evaluate the person’s status. The aim is to achieve a high “chest compression fraction,” meaning compressions are being delivered for more than 60% of the resuscitation time.
Proper Technique and Duration of the Pulse Check
The technique for checking the pulse during CPR must be executed quickly to minimize the stoppage of compressions. For adults and children, the standard location is the carotid artery, adjacent to the trachea. This central artery is often easier to palpate than peripheral pulses during a circulatory collapse.
In infants, the recommended location for checking a pulse is the brachial artery, located on the inside of the upper arm, between the elbow and the shoulder. Regardless of the location, the most significant procedural detail is the time limit. The pulse check must not last longer than 10 seconds under any circumstances.
This strict 10-second maximum is a scientific necessity. Prolonged interruptions in chest compressions cause a drop in coronary perfusion pressure. Once compressions stop, this pressure decreases quickly, and it takes several compressions to rebuild it, making a long pause detrimental to the outcome. If a pulse cannot be confirmed within that 10-second window, the rescuer must immediately resume compressions.
Adjusting Care and When to Stop CPR
The outcome of the pulse check dictates the next course of action in the resuscitation effort. If the pulse check confirms ROSC (Return of Spontaneous Circulation), compressions should be stopped immediately. The rescuer should then monitor the person’s breathing and be prepared to provide rescue breaths if breathing is inadequate.
If the two-minute pulse check reveals no pulse, or a pulse too slow or weak to support life, the rescuer must restart chest compressions without delay. This cycle of two minutes of CPR followed by a brief pulse check continues until the person shows signs of life or until a trained medical team takes over.
Lay rescuers are advised to continue CPR until one of several conditions is met. These conditions include:
- The arrival of trained emergency medical services personnel who can take over the resuscitation effort.
- The rescuer becomes physically exhausted and can no longer perform effective compressions.
- The person clearly shows signs of life, such as purposeful movement, coughing, or normal breathing.