What factors determine the actual O2 delivered by an air-entrainment system?

The actual oxygen delivered by an air-entrainment system is influenced by multiple factors, primarily the air to oxygen ratio of the device and the resistance downstream from the jet.

The air to oxygen ratio determines the proportion of air and oxygen mixed in the system. This ratio is crucial because it directly affects how much oxygen is delivered to a patient. For instance, if the ratio allows for a greater proportion of oxygen, then more oxygen will be available for delivery.

Resistance downstream from the jet can significantly impact the performance of the device, as it may restrict airflow and alter the way ambient air is entrained into the system. Increased resistance can reduce the total flow through the device, leading to a decrease in the actual concentration of oxygen delivered.

Thus, both the air to oxygen ratio and downstream resistance need to be considered to accurately assess the oxygen delivery of an air-entrainment system. This interplay ultimately determines the efficiency and effectiveness of oxygen delivery in a clinical setting.