Can You Use a Bag Valve Mask Without Oxygen?
Yes, a bag valve mask (BVM) can absolutely be used to deliver rescue breaths without supplemental oxygen—the self-inflating bag delivers room air (approximately 21% oxygen) when no oxygen source is attached, which is sufficient for effective ventilation during resuscitation. 1
How BVM Works Without Oxygen
- A self-inflating bag delivers only room air unless supplementary oxygen is attached, but this room air ventilation is still effective for maintaining oxygenation and adequate ventilation during CPR 1
- The American Heart Association explicitly states that a bag-mask device provides "mask ventilation with room air or oxygen", confirming both options are viable 1
- When used without oxygen, the BVM delivers approximately 21% oxygen (room air), compared to 30-80% with oxygen flow at 10 L/min, or 60-95% when an oxygen reservoir is attached 1
When to Use Supplemental Oxygen
While room air ventilation works, healthcare providers should use supplementary oxygen (concentration >40%, at minimum flow rate of 10-12 L/min) when available 1
- For optimal oxygen delivery (60-95%), attach an oxygen reservoir to the self-inflating bag with flow rates of 10-15 L/min for pediatric bags and at least 15 L/min for adult bags 1
- Research shows that 10 L/min for 1 minute followed by 5 L/min can achieve FiO2 >0.85 during CPR, allowing substantial reduction in oxygen requirements 2
- However, the absence of supplemental oxygen should never delay or prevent rescue breathing—room air ventilation is far superior to no ventilation 1
Critical Technical Points
Effective BVM ventilation requires proper technique regardless of oxygen availability:
- Deliver approximately 600 mL tidal volume for adults (squeeze a 1-L bag about two-thirds or a 2-L bag about one-third) to produce visible chest rise 1
- Give each breath over 1 second and watch for chest rise 1
- Two-person technique is strongly preferred: one rescuer uses both hands to maintain airway and mask seal while the other squeezes the bag 1, 3
- For a lone rescuer during CPR, mouth-to-barrier device techniques are preferred over single-person BVM due to the complexity of maintaining adequate seal and airway 1
Common Pitfalls to Avoid
- Avoid excessive ventilation—use only enough force to make the chest visibly rise, as excessive ventilation increases intrathoracic pressure, impedes venous return, and decreases cardiac output 1
- If chest doesn't rise, reopen the airway and verify tight mask-to-face seal before reattempting 1, 4
- Never delay rescue breathing while searching for oxygen equipment—begin ventilation with room air immediately 1