| Physiologic benefit | Mechanism |
| Decrease in dead space | O2 from catheter enters the trachea lower in the airways, decreasing dead space. |
| Decrease in total inspired minute ventilation | Due to flow from the catheter, less gas is inspired at the mouth, reducing work of breathing. |
| Increase in CO2 elimination efficiency | Fresh gas flowing from the catheter flushes the area proximal to the catheter tip during expiration, reducing the amount of CO2 that returns to the alveoli with the next inspiratory cycle. In addition, gas exiting the catheter tip at high velocity generates turbulence that enhances gas mixing distal to the catheter tip, increasing CO2 washout. As a consequence, PaCO2 remains unchanged despite a decrease in total inspired minute ventilation. |
