The Role of Oxygen Saturation in Venous Blood Gas

The oxygen saturation of the venous blood gas can give you a concept of how much cellular respiration is going on in the hands. The VBG PCO2 is always going to tend to be higher than the arterial sample, so even if it's not perfect we can tolerate some wiggle room for patients with conditions like COPD or heart failure. With the caveat being that if your patient is Oh dear God in physical restraints, fighting people, the limb is turnicated or has a turn a kid on it, and the VBG might not be as reliable as we hope. So just summarize that to hammer it home for me.