With a reservoir attached to a manual resuscitator, what concentration of oxygen can be approached?

When using a manual resuscitator that is equipped with a reservoir, the device is capable of delivering a very high concentration of oxygen to the patient. The presence of a reservoir allows for the collection of oxygen, enabling the resuscitator to provide nearly 100% oxygen whenever the bag is compressed.

In clinical practice, it is understood that the efficiency of oxygen delivery is significantly improved by using a reservoir. This setup minimizes the dilution of the oxygen with ambient air during the resuscitation process. Consequently, as the bag is squeezed and the patient's lungs are being filled with air, it is primarily oxygen from the reservoir that is being delivered, making it possible to achieve concentrations that can be extremely close to 100%.

In contrast, without a reservoir or with a less effective setup, the concentration of oxygen would be much lower due to the mixing of room air, which is not the case here. Thus, with the use of a reservoir, it is indeed feasible to approach and deliver concentrations of oxygen that are close to 100%.