CPR is exhausting. Good quality chest compressions performed correctly will tire even a fit rescuer within about two minutes, and tired compressions become shallow compressions, which means less blood reaching the brain and heart. Knowing how to change over smoothly between two rescuers keeps compression quality high for as long as it takes for help to arrive.
Why Changeover Matters
Compression quality drops off noticeably after around two minutes of continuous effort, often before the rescuer even feels tired enough to notice. Swapping rescuers on a schedule, rather than waiting until someone is exhausted, keeps compressions deeper and more consistent throughout the resuscitation attempt.
When to Change Over
Change rescuers approximately every two minutes, which typically lines up with a rhythm check if an AED is attached. Plan the swap to take no more than a few seconds, since every pause in compressions reduces blood flow that then has to build back up again.
How to Change Over Smoothly
- The second rescuer kneels on the opposite side of the patient, ready to take over, before the current compressor reaches the end of their cycle.
- At the end of a set of 30 compressions, the rescuer performing compressions moves back and the new rescuer moves into position immediately.
- The new rescuer begins compressions right away, minimising any gap in chest compressions.
- The rescuer who just finished compressing can take over giving rescue breaths, or step back to rest and call for help if this has not already been done.
Two Rescuer CPR
With two trained rescuers working together, one performs continuous chest compressions while the other manages the airway and gives rescue breaths after every 30 compressions for adults. This division of tasks also means breaths can be given more precisely, since the same rescuer maintains the head position and seal throughout.
Communicating During a Changeover
Say clearly when you are ready to swap and confirm out loud once the new rescuer has started compressions. In a chaotic scene with bystanders and noise, a clear verbal handover prevents both rescuers accidentally stopping at once, which can happen more easily than people expect under stress.
What to Do If You Are Alone and Get Tired
If you are performing CPR alone and become exhausted, continue as best you can rather than stopping altogether. Even imperfect compressions are better than none. If a bystander is present but untrained, you can talk them through basic compressions while you rest briefly, since some chest compression is better than a complete pause.
Frequently Asked Questions
How often should rescuers change over during CPR?
Approximately every two minutes, since compression quality tends to drop off around that point even in a fit rescuer.
Why does changing over during CPR matter so much?
Tired rescuers give shallower, less effective compressions, often without realising it, which reduces blood flow to the brain and heart.
Should you stop CPR completely if you are exhausted and alone?
No. Continue with the best compressions you can manage, or ask an untrained bystander to help, rather than stopping entirely.
Related Guides
- CPR for Adults: Current Technique and Compression Ratios
- CPR for Infants and Children: Technique and Key Differences from Adults
- DRABC Primary Survey: The Basic Life Support Flow Chart Explained
- Expired Air Resuscitation: Mouth to Mouth, Mouth to Nose and Mouth to Mask
References and Last Reviewed
- American Heart Association, Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
- International Liaison Committee on Resuscitation (ILCOR), Consensus on Science and Treatment Recommendations
Jurisdiction: General first aid guidance, internationally applicable.
Last technically reviewed: September 2026
Reviewed by: EHS Guidelines Editorial Team
This article is educational and does not replace accredited first aid training or professional medical care. In a real emergency, call your local emergency number immediately.
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