Bag Valve Mask Functionality Without Supplemental Oxygen
Yes, a Bag Valve Mask (BVM) will work without being connected to supplemental oxygen, as it can deliver room air (21% oxygen) to the patient through manual ventilation. 1
How BVMs Work With and Without Oxygen
Basic Functionality
- A self-inflating BVM delivers room air (21% oxygen) when not connected to an oxygen source 1
- The self-inflating mechanism allows the bag to refill automatically after each compression
- Manual compression of the bag creates positive pressure ventilation to the patient
Oxygen Concentration Differences
- Without supplemental oxygen: delivers only 21% oxygen (room air) 1
- With supplemental oxygen at 10-15 L/min: delivers 30-80% oxygen concentration 1
- With oxygen reservoir attached and flow of 10-15 L/min: delivers 60-95% oxygen 1
Clinical Implications
Effectiveness for Ventilation
- BVM without oxygen is effective for delivering ventilation (moving air in and out of lungs)
- However, it provides lower oxygen concentration than when supplemental oxygen is attached
- The American Heart Association confirms BVMs can provide positive-pressure ventilation with room air or oxygen 1
When to Use BVM Without Oxygen
- Emergency situations when oxygen is unavailable
- Initial ventilation support while oxygen is being set up
- Short-term ventilation during transport to higher level of care
- During CPR when immediate ventilation is needed 1
Technical Considerations
BVM Size Requirements
- For adults: Use a self-inflating bag with volume of 1-2 L 2
- For infants/young children: Use a self-inflating bag with volume of at least 450-500 mL 1, 2
- For older children/adolescents: May need an adult self-inflating bag (1000 mL) to achieve adequate chest rise 1
Proper Technique
- Deliver each breath over approximately 1 second 1
- Watch for visible chest rise as the primary indicator of effective ventilation 2
- If chest doesn't rise, reopen airway, verify mask seal, and reattempt 2
- Avoid excessive ventilation which can impede venous return and decrease cardiac output 1, 2
Important Cautions
Potential Limitations
- Some BVM designs may perform poorly even with oxygen attached 3
- Devices with duckbill non-rebreather valves and without dedicated expiratory valves may perform worst 3
- Bag-mask ventilation is a challenging skill requiring considerable practice for competency 1
Two-Person Technique Recommended
- Effective bag-mask ventilation requires a tight seal between mask and face 1
- Two-person technique is preferred: one person maintains airway and mask seal while the other compresses the bag 1, 2
- For a lone rescuer during CPR, mouth-to-barrier device techniques may be more effective than attempting BVM alone 1
Bottom Line
A BVM will function without supplemental oxygen by delivering room air (21% oxygen), but when available, supplemental oxygen should be added to increase the delivered oxygen concentration and improve patient outcomes, especially in hypoxic conditions.