CPR is a life-saving technique used when a person’s heart has stopped beating. Effective CPR circulates oxygenated blood to the brain and other vital organs until professional medical help arrives. The quality of chest compressions directly influences the patient’s chances of survival and neurological recovery. Because continuous chest compressions quickly lead to rescuer fatigue, a planned system for switching rescuers is important for maintaining performance.
Defining High-Quality CPR
High-Quality CPR is defined by specific, measurable metrics that maximize blood flow during cardiac arrest. The American Heart Association (AHA) guidelines specify that chest compressions must be delivered at a consistent rate of 100 to 120 compressions per minute. Compression depth is equally important, requiring the sternum of an adult to be pushed down at least 2 inches, but not exceeding 2.4 inches, to effectively squeeze the heart.
Another element is ensuring full chest recoil between each compression, meaning the rescuer must avoid leaning on the chest so the heart can adequately refill with blood. Also, interruptions to compressions—known as “hands-off time”—must be minimized to maintain a high chest compression fraction (CCF), ideally greater than 80%. When a rescuer becomes fatigued, these metrics, particularly compression depth, begin to decline, compromising the effectiveness of the resuscitation effort.
The Recommended Rescuer Switch Interval
The standard recommendation for switching the person performing chest compressions is every two minutes. This two-minute interval aligns with the time frame after which compression quality is shown to deteriorate due to physical exhaustion, even in highly trained individuals. Studies indicate that muscle fatigue often begins to set in quickly, sometimes reducing the adequacy of compression depth after only one minute of continuous effort.
Switching every two minutes helps preempt this decline, ensuring the person delivering compressions is always fresh and capable of meeting the high-quality metrics. In a two-rescuer scenario following the standard 30 compressions to 2 breaths ratio, this two-minute period typically equates to five complete cycles. The rescuer responsible for ventilation or the team leader should actively monitor the time and the compressor’s technique to initiate the switch before performance drops.
Executing the Switch with Minimal Delay
Once the two-minute interval is reached, or earlier if signs of fatigue are visible, the switch must be executed with speed and precision. The goal is to minimize the interruption in blood flow, ideally less than five seconds. Clear verbal communication is paramount, with the person monitoring the time announcing the upcoming change using a specific phrase, such as “Switch on the next cycle.”
The incoming rescuer should already be positioned next to the patient, ready to take over the moment the current compressor finishes their final set. In the common 30:2 ratio sequence, the switch is often timed to occur during the brief pause for the two rescue breaths. As the outgoing rescuer moves away, the new compressor immediately places their hands and begins compressions without delay, ensuring the rhythm is maintained.