What is a good end tidal volume (ETV) range for cardiopulmonary resuscitation (CPR)?

End-Tidal Volume (ETV) Range for Cardiopulmonary Resuscitation (CPR)

During CPR, a tidal volume of 500-600 mL (6-7 mL/kg of predicted body weight) is recommended to produce visible chest rise while avoiding excessive ventilation. 1

Optimal Ventilation Parameters During CPR

Tidal Volume

• The American Heart Association (AHA) recommends a tidal volume of approximately 500-600 mL (6-7 mL/kg of predicted body weight) during adult CPR 1
• This volume is typically sufficient to:
  • Produce visible chest rise
  • Maintain adequate oxygenation
  • Maintain normocarbia in apneic patients

Respiratory Rate

• For patients without advanced airways: Use 30:2 compression-to-ventilation ratio 1
• For patients with advanced airways in place (endotracheal tube, supraglottic device):
  • Deliver 1 breath every 6-8 seconds (8-10 breaths/minute)
  • No need to synchronize with compressions 1

Monitoring End-Tidal CO₂ During CPR

End-tidal CO₂ (ETCO₂) monitoring provides valuable information during CPR:

• ETCO₂ values >1.9 kPa (14.3 mmHg) after 20 minutes of resuscitation strongly predict return of spontaneous circulation (ROSC) 2, 3
• ETCO₂ levels typically:
  • Decrease from ~4.5% initially to ~1.5-2.5% during prolonged CPR 4
  • Rise rapidly (to ~3.7%) when spontaneous circulation returns 4
• Changes in ETCO₂ are often the first indication of ROSC 4

Avoiding Common Pitfalls

Excessive Ventilation

• AVOID excessive ventilation (too many breaths or too large volumes) as this can:
  • Increase intrathoracic pressure
  • Decrease venous return to the heart
  • Reduce cardiac output and survival 1
  • Cause gastric inflation, regurgitation, and aspiration 5

Inadequate Ventilation

• Inadequate tidal volumes (below recommended range) may:
  • Fail to provide sufficient oxygenation
  • Result in inadequate CO₂ removal
  • Lead to respiratory acidosis 5

Air Trapping

• High respiratory rates combined with high tidal volumes (e.g., 33 breaths/min with 18 mL/kg) can cause:
  • Air trapping
  • Elevated airway pressures
  • Persistent expiratory airflow before breath delivery 6

Clinical Application

1. Deliver each rescue breath over 1 second 1
2. Ensure visible chest rise with each ventilation 1
3. Use appropriate equipment:
   • For bag-mask ventilation: Use adult (1-2 L) bag to deliver approximately 600 mL tidal volume 1
   • Ensure ability to bypass pressure-relief valves if necessary to achieve visible chest expansion 1
4. Monitor ETCO₂ when available:
   • Values consistently below 10 mmHg after 20 minutes of resuscitation suggest poor prognosis 3
   • Rising ETCO₂ values may indicate ROSC 4

By maintaining appropriate tidal volumes (500-600 mL) and avoiding excessive ventilation during CPR, you can optimize cardiopulmonary function while minimizing potential adverse effects on hemodynamics.