During cardiopulmonary resuscitation (CPR), should chest compressions be paused while delivering rescue breaths?

Should Chest Compressions Be Paused for Rescue Breaths During CPR?

Yes, chest compressions should be paused briefly (less than 10 seconds) to deliver 2 rescue breaths when performing CPR without an advanced airway, using a 30:2 compression-to-ventilation ratio. 1, 2, 3

Key Distinction: With or Without Advanced Airway

The answer depends critically on whether an advanced airway (endotracheal tube or supraglottic airway) is in place:

Without Advanced Airway (Most Common Scenario)

• Pause compressions briefly to deliver 2 breaths after every 30 compressions
• Keep the pause under 10 seconds 3, 4
• Each breath should take approximately 1 second 5
• This 30:2 ratio applies to both lay rescuers trained in conventional CPR and healthcare providers 1, 2

Rationale: The most recent 2020 AHA guidelines 2 and 2018 focused update 1 consistently recommend this approach. A large trial showed that EMS-delivered 30:2 CPR (with brief pauses under 5 seconds) was associated with better survival and neurological outcomes compared to continuous compressions with asynchronous ventilation 2, 6.

With Advanced Airway in Place

• Do NOT pause compressions for ventilation
• Deliver continuous chest compressions at 100-120/minute
• Provide asynchronous ventilation at 1 breath every 6 seconds (10 breaths/minute) 2, 3, 5

Evidence Quality and Nuances

The 2020 guidelines 2 provide the most current recommendations, supported by moderate-to-high quality evidence:

• For trained rescuers: The 30:2 ratio with brief pauses is reasonable (Class IIa, Level B-R) 2
• Chest compression fraction target: Aim for at least 60% of total CPR time devoted to compressions 3, 4
• Critical caveat: Pauses must be minimized—the guidelines emphasize keeping interruptions as short as possible 3, 4

Important Distinction for Lay Rescuers

For untrained lay rescuers, compression-only CPR is recommended 1, 3, 1. However, for trained lay rescuers who know how to deliver rescue breaths, adding ventilation with the 30:2 ratio is reasonable and may improve outcomes, particularly in non-cardiac causes of arrest 1, 3.

The Physiology Behind the Recommendation

Research shows that interrupting compressions does cause temporary drops in coronary perfusion pressure 7, and animal studies demonstrated adverse hemodynamic effects from ventilation pauses 8, 7. However, human trials found that:

• Brief pauses (under 10 seconds) for ventilation do not worsen survival 9
• The 30:2 ratio balances the need for oxygenation with maintaining adequate perfusion 2, 6
• Most trained rescuers can deliver 2 breaths in under 10 seconds and still achieve >70 compressions per minute 9

Common Pitfalls to Avoid

1. Excessive pause duration: Taking more than 10 seconds to deliver breaths significantly reduces chest compression fraction
2. Hyperventilation: Delivering breaths too frequently or with excessive volume increases intrathoracic pressure and decreases venous return
3. Continuing 30:2 after advanced airway placement: Once an ETT or supraglottic airway is placed, switch immediately to continuous compressions with asynchronous ventilation 2, 5
4. Using mechanical ventilators during CPR: Ventilators may erroneously trigger from chest compressions, delivering excessive breaths—use manual ventilation instead 10

Special Populations

For asphyxial arrests (drowning, choking), ventilation is particularly critical and should not be omitted 11. The evidence supporting compression-only CPR applies primarily to cardiac causes of arrest.