A bag-valve-mask device with an oxygen reservoir can deliver up to ____ of oxygen with flow rates at 10-15 liters per minute.

A bag-valve-mask device with an oxygen reservoir can deliver up to ____ of oxygen with flow rates at 10-15 liters per minute.

• A. 95%
• B. 50%
• C. 60%
• D. 80%

Answer: (A)

The device’s oxygen reservoir plays a key role in delivering a very high fraction of inspired oxygen. When you use a bag-valve-mask with the reservoir and operate at 10–15 L/min, the reservoir stays filled with oxygen and most of the gas the patient inhales comes from that reservoir rather than room air. The one-way valves also prevent inhaling exhaled gas, further reducing dilution with ambient air. This setup can push FiO2 close to 95%, which is why that option is best. It isn’t 100% because a small amount of room air can still mix in through slight mask leaks and the exhalation ports, so the concentration has an upper limit around the mid-90s. The other numbers reflect lower oxygen concentrations typical of masks without reservoirs or with lower flow.

The device’s oxygen reservoir plays a key role in delivering a very high fraction of inspired oxygen. When you use a bag-valve-mask with the reservoir and operate at 10–15 L/min, the reservoir stays filled with oxygen and most of the gas the patient inhales comes from that reservoir rather than room air. The one-way valves also prevent inhaling exhaled gas, further reducing dilution with ambient air. This setup can push FiO2 close to 95%, which is why that option is best. It isn’t 100% because a small amount of room air can still mix in through slight mask leaks and the exhalation ports, so the concentration has an upper limit around the mid-90s. The other numbers reflect lower oxygen concentrations typical of masks without reservoirs or with lower flow.