Bystander cardiopulmonary resuscitation (CPR) is a time-sensitive intervention. For every minute that passes without chest compressions, the survival rate decreases by approximately 7 to 10 percent. Immediate, high-quality CPR helps circulate oxygenated blood to the brain and vital organs until professional medical help arrives. While the arrival of Emergency Medical Services (EMS) personnel brings advanced care, the rescuer should not immediately stop compressions. The goal of every rescuer is to minimize interruptions to chest compressions.
The Necessity of Uninterrupted CPR
The effectiveness of CPR is directly linked to the continuous blood flow provided to the heart and brain. Chest compressions increase pressure inside the chest cavity, generating coronary perfusion pressure necessary to sustain the heart muscle. When compressions stop, this pressure immediately drops to zero, and it takes several uninterrupted compressions to build it back up. Any “no-flow time” starves the heart and brain of oxygen, reducing the chance of a successful outcome. Therefore, professional guidelines emphasize maintaining a compression fraction of at least 60 percent, meaning the bystander must continue high-quality compressions until relieved.
Performing the Handoff: Specific Steps for Transition
When the EMS team arrives, the bystander must focus on a smooth, coordinated transfer of care that avoids stopping compressions. Continue compressions while communicating clearly what you have done, such as the patient’s status and the number of compressions given. As EMS personnel position their equipment, you may need to move slightly while maintaining the correct rate of 100 to 120 compressions per minute. Stop compressions only on the direct instruction of the EMS provider who is physically prepared to immediately assume the role. When the EMS provider commands “stop,” they are ready to shock the patient or begin their own cycle, minimizing the interruption to under 10 seconds.
Your Role as a Bystander After EMS Takes Over
Once the EMS team has fully taken over CPR, the bystander moves into a support and advisory role. The first step is to create space for the professionals to work, as this involves complex procedures and specialized equipment. Stepping back ensures the safety of the patient and allows the team to maneuver quickly, especially when a defibrillator is in use. The most valuable contribution after the handoff is providing a detailed history of the event. Relay information such as the time the cardiac arrest occurred, what the patient was doing when they collapsed, and any known medical conditions, as this helps the EMS team determine the appropriate advanced treatment plan.