What is the primary goal of administering CPAP to a non-dependent lung during surgery?

Administering Continuous Positive Airway Pressure (CPAP) to a non-dependent lung during surgery primarily aims to improve oxygenation. In a surgical setting, particularly when a patient is positioned in such a way that one lung is more dependent than the other, the lower lung may not receive adequate ventilation. By employing CPAP to the non-dependent lung, you can help to recruit collapsed alveoli and promote better ventilation-perfusion matching. This, in turn, enhances the diffusion of oxygen into the bloodstream, leading to improved overall oxygenation levels.

The presence of CPAP effectively keeps the airways open, which helps maintain functional residual capacity and prevents atelectasis, potentially leading to better outcomes related to oxygen delivery during surgery. Therefore, the primary focus when using CPAP in this context is to optimize the lung's ability to oxygenate the blood, especially in scenarios where one lung may be compromised or inherently less perfused.