Why to use oximeter during cardiac catheter procedure?

and why to use the whole blood oximeter(taking blood samples) instead of using Pulse Oximeter ?

To have an accurate reading of the oxygen concentration of blood samples from various chambers of the heart. This ,as you may know,vary e.g. the right side of the heart (deoxygenated) and the left side (oxygenated) .

Pulse oximetry gives only the oxygen concentration in the blood in arterioles and capillaries and these reflect the blood coming from the left side of the heart only.

Hope this answers your question.

Oximeter is to look at oxygen levels in your blood to make sure you are breathing and circulating oxygen into your tissues appropriately. Very important thing. They want to maintain tissue oxygenation and perfusion during any procedure, especially important if you will be knocked out for this procedure as you won't be able to tell them.

I suppose they would use the blood because it is more accurate. Pulse ox is good, but can be thrown off by movement or if you are anemic or if your blood pressure drops. The blood measure would be more accurate. Heck, during a cardiac cath they have access to your blood anyway so may as well check it while they are in there.

Yes, using the oximeter during the cath makes sure that your are breathing enough after you have been administered sedation. Many sedatives suppress the respiratory system, and if during the heart cath your breathing slowed so the the oxygen sat dropped below 92%, the nurse would give you supplemental oxygen.

I have never heard of anyone using blood gas measurements (as you call whole blood oximeter readings) in a regular left heart cath. In the lab I work in we take blood gases while doing a right heart cath. When patients have leaking valves and low cardiac output, the cardiologist takes samples from the right and left side of the heart. That way he can analyze if there is any shunting of blood, back flow of blood and several other blood flow problems.

I hope this helped answer your question.