Cardiopulmonary resuscitation (CPR) is a life-sustaining measure during cardiac arrest. Chest compressions are the core component of CPR, circulating blood throughout the body. These compressions help maintain blood flow to the brain and other essential organs, delaying cell death until the heart can be restarted. Effective compressions are important because cells begin to die within minutes of the heart stopping.
Maintaining Compression Quality
Effective CPR relies on delivering high-quality chest compressions. Compressions should be delivered at a rate of 100 to 120 per minute, with a depth of at least 2 inches (5 cm) but no more than 2.4 inches (6 cm) in adults. Allowing the chest to fully recoil after each compression is important, as is minimizing interruptions to blood flow. Performing these actions correctly is physically demanding, and rescuer fatigue can quickly compromise compression quality. Compression quality, particularly depth, can decline even within the first minute or two of continuous CPR.
Signals for Alternation
Rescuer fatigue is the primary signal for alternating compressions. Even trained individuals can experience a decrease in compression quality, such as reduced depth or rate, within a few minutes of continuous effort. To counteract this, it is recommended to switch rescuers approximately every two minutes, or after about five cycles of 30 compressions and two breaths if ventilations are being provided. Visible signs of fatigue, including slowing compressions, decreased depth, or overt physical strain, also indicate a switch is necessary. Some research suggests that switching roles every minute may result in higher compression quality and less rescuer fatigue.
Executing a Seamless Switch
Performing a smooth and rapid switch between rescuers is important to minimize interruptions in chest compressions. The goal is to complete the transition in less than 5 to 10 seconds. Clear communication between rescuers is important. The incoming rescuer should pre-position themselves, ready to take over as the current rescuer finishes their cycle. This coordinated effort ensures continuous blood flow, which is important for patient outcomes.
Single Rescuer Scenarios
In situations where only one rescuer is present, the approach differs. A lone rescuer should continue providing high-quality chest compressions without stopping to alternate. The priority in this scenario is maintaining continuous compressions to support blood flow until additional help arrives, an automated external defibrillator (AED) becomes available, or signs of life return. While physically challenging, continuous compressions by a single rescuer are considered highly beneficial for the patient.