What is the appropriate oxygen concentration delivered by a bag-valve-mask resuscitator?

The correct answer reflects that a bag-valve-mask (BVM) resuscitator can deliver an oxygen concentration of approximately 20% to 21% when used properly. This concentration is achieved because, when the device is utilized in conjunction with supplemental oxygen, it allows for a higher concentration of oxygen to be delivered to the patient.

Using a BVM with a reservoir bag, and when the mask is fitted correctly over the patient’s mouth and nose, the device effectively channels both ambient air and supplemental oxygen. While the normal atmospheric air contains about 21% oxygen, the BVM's design enhances the delivery of this oxygen to the patient, especially when tuned to supply adequate positive pressure.

The range provided also indicates that while the BVM can supply a high percentage of supplemental oxygen, it may not reach the higher percentages typically associated with advanced ventilation methods or specialized equipment. This context is critical for understanding how to implement BVM use effectively in situations such as cardiac arrest or respiratory failure, where oxygen delivery is vital for patient survival.

Other choices suggest higher concentrations that are not attainable purely with the BVM without advanced interventions. Thus, it's essential to be aware that while a BVM is an effective tool, it has specific limitations in oxygen