Here's something interesting to think about. Now, for simplicity purposes, let us assume that the hypoxic drive is real, that if a COPD retainer is given too much oxygen he will stop breathing.
So, that in mind, many doctors do not want to give a COPD patient oxygen even when his sats are low, and even at the risk that his heart and brain won't get enough oxygen.
Yet, think of this. The hypoxic drive is based on arterial PO2. If you give a COPD patient 100% oxygen, and his sat is still in the 80s, that means that oxygen isn't getting to the arterioles anyway. Hence, it shouldn't effect the hypoxic drive.
Thus, if you have a CO2 retainer, and assuming the hypoxic drive is real, you should be able to give as much oxygen as is needed to maintain an appropriate PO2, like say something around 88% would even be nice.
And even while the oxygen is not making it to the arterioles, and not sitting on hemoglobin, excess oxygen will disolve in the plasma. Oxygen bound to hemoglobin isn't of much use immediately because it's being stored, and it must be chemically separated from the hemoglobin.
Oxygen is not just transported in the body by hemoglobin, it's transferred in the plasma as well. This "disolved" oxygen is available right away because it doesn't have to be separated from hemoglobin. It is of use to the body, although it will not register on a pulse oximeter, and it will not register on an ABG PO2 either.
Medical schools teach that the amount of blood transported by plasma is so insignificant it's not worth even mentioning. Yet this is not true. Science has proven it.
This is just something one of my coworkers brought to my attention. Thoughts?
Reference: My anonymous source will be referenced here when his book is published. I hope it's soon because I can't wait to purchase a copy and set it where the physicians sit every day.