What is the compression-to-ventilation ratio in cardiopulmonary resuscitation (CPR)?

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Compression-to-Ventilation Ratio in CPR

The compression-to-ventilation ratio in CPR is 30:2 for single rescuers (both lay rescuers and healthcare providers) and 15:2 for two healthcare providers performing CPR in infants and children.

Rationale for Different Ratios Based on Rescuer Number

Single Rescuer CPR

  • Use a 30:2 compression-to-ventilation ratio regardless of patient age (adults, children, or infants) 1.
  • This ratio maximizes the number of chest compressions delivered while minimizing interruptions in blood flow 1.
  • The 30:2 ratio yields more chest compressions than a 15:2 ratio with minimal or no increase in rescuer fatigue 1.
  • Studies demonstrate that 30:2 results in less "no flow time" (time without chest compressions) compared to 15:2 1.

Two-Rescuer CPR (Healthcare Providers)

  • For infants and children, use a 15:2 compression-to-ventilation ratio when two healthcare providers are performing CPR 1.
  • This allows for more frequent ventilations, which is particularly important in pediatric cardiac arrest where the etiology is typically asphyxial rather than cardiac 1.
  • The 15:2 ratio is reasonable for two rescuers because one can focus on compressions while the other manages the airway, making more frequent ventilations feasible without significantly compromising compression quality 1.

Key Physiological Principles

Importance of Minimizing Interruptions

  • Coronary perfusion pressure rapidly declines when chest compressions are interrupted, and several compressions are needed to restore it once resumed 1.
  • Frequent interruptions prolong the duration of low coronary perfusion pressure and reduce the likelihood of return of spontaneous circulation (ROSC) 1.
  • Animal studies consistently demonstrate that interruptions in chest compressions are detrimental to resuscitation success 1.

Compression Quality Over Quantity

  • After each set of compressions, provide 2 effective ventilations using as short a pause as possible 1.
  • Each breath should take approximately 1 second and should make the chest rise 1.
  • Continue cycles for approximately 2 minutes (about 5 cycles) before reassessing 1.

Special Considerations

Advanced Airway in Place

  • When an advanced airway (endotracheal tube) is in place, provide continuous chest compressions without pausing for ventilations 1.
  • Deliver ventilations at a rate of 1 breath every 2-3 seconds (20-30 breaths/min) while compressions continue uninterrupted 1.

Compression-Only CPR

  • If bystanders are unwilling or unable to provide rescue breaths, compression-only CPR is superior to no CPR 1.
  • Large observational studies show that compression-ventilation CPR produces better outcomes than compression-only CPR in children, though compression-only CPR is still beneficial when rescue breaths cannot be provided 1.

Common Pitfalls to Avoid

  • Do not use outdated ratios: The 5:1 ratio previously recommended (2000 and earlier) has been abandoned because lone rescuers cannot deliver adequate compressions per minute with this ratio 1.
  • Avoid excessive pauses for ventilation: Keep ventilation pauses as brief as possible to maintain coronary perfusion pressure 1.
  • Do not hyperventilate: Excessive ventilation rates can compromise hemodynamics during CPR 1.

References

1
Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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