Chest Compression Fraction (CCF) represents the percentage of time during a cardiac arrest event that a person is receiving chest compressions. When blood flow to the brain and heart stops, every moment without compressions diminishes the chances of a positive outcome. A higher CCF is associated with better survival rates because it maximizes the circulation of oxygenated blood. Modern resuscitation efforts focus on strategies that keep hands on the chest, with a target CCF of at least 80%.
Minimizing Pauses in the CPR Cycle
A primary objective in achieving a high chest compression fraction is to reduce the duration of any interruption. Each time compressions stop, blood pressure to the heart and brain drops rapidly, and it takes time to rebuild that pressure once compressions resume. The goal is to keep all interruptions to an absolute minimum, preferably under 10 seconds.
One of the most common reasons for pausing compressions is to deliver a shock with a defibrillator. An effective way to shorten this “pre-shock pause” is to pre-charge the defibrillator. This involves continuing compressions while the machine charges, so it is ready to deliver the shock the instant compressions are halted for a heart rhythm analysis. Studies show that a five-second increase in the pre-shock pause can significantly reduce the likelihood of successful defibrillation.
Pauses for providing rescue breaths are another area for optimization. For rescuers working without an advanced airway, delivering two breaths should take less than 10 seconds before compressions restart. When a patient has a secure airway, such as an endotracheal tube, teams can use asynchronous ventilations. This technique involves providing one breath every six seconds without stopping chest compressions, eliminating pauses for ventilation.
Implementing Efficient Team Dynamics
The coordination of the resuscitation team directly impacts the continuity of chest compressions. Fatigue is a factor that degrades the quality of compressions, necessitating switches between rescuers, and an inefficient switch adds unnecessary seconds to off-chest time. A well-executed switch involves the next compressor getting into position beside the current one, ready to take over immediately. The exchange should be announced in advance and completed in less than five seconds.
Many high-performing systems adopt a “pit crew” model, inspired by motorsport teams. In this approach, each team member has a pre-assigned role and a specific location around the patient. These roles can include a designated compressor, someone to manage the airway, a defibrillator operator, and a team leader who oversees the effort. This structure eliminates confusion and hesitation, as everyone knows their responsibilities.
Clear and direct communication underpins effective team dynamics. A method known as closed-loop communication is useful in these high-stress situations. The team leader gives a clear command to a specific team member, who then verbally confirms they heard the instruction and are performing the task. This ensures messages are received and acted upon correctly, preventing delays or errors.
Leveraging Real-Time Feedback Devices
Technology now offers tools that can guide rescuers and help them maintain a high chest compression fraction. CPR feedback devices, which can be integrated into defibrillator pads or exist as standalone units, provide live data on performance. These devices use sensors to measure the metrics of CPR quality as it is being delivered.
These tools provide real-time audiovisual cues to the resuscitation team. They monitor the rate of compressions, ensuring it stays within the recommended 100-120 compressions per minute, and measure the depth of each push. Many modern devices also track chest recoil to ensure the chest fully expands between compressions. These devices often display the chest compression fraction as a live percentage, giving the team an immediate understanding of their performance.
The benefit of this technology is its ability to facilitate immediate correction. Instead of relying on estimation, rescuers receive objective data that allows them to adjust their technique on the spot. If the compression rate slows, a metronome might beep faster, or if depth is too shallow, a visual cue will prompt the rescuer to push harder. By monitoring for pauses and tracking the CCF, these devices help teams identify excessive hands-off time, prompting them to resume compressions more quickly.