[Laurel]

Katherine,

Apparently Keytruda can cause an allergic lung inflammation and low RBCs, both of which would cause poor blood oxygenation. It appears the above are both relatively rare, but are listed side effects. My suggestion would be to speak with a covering doc asking for blood work to see how your RBCs are holding up. Apparently your body would be attacking those and destroying them if they are found to be dropping. Interesting response. It may be that this is an allergic immuno response in both cases and can be treated with steroids perhaps, or another method to tamp down the immune system's activity. As I said earlier, perhaps this is an initial reaction which will abate with time, but I would certainly press them a bit for an explanation and treatment of the symptoms if warranted beyond the oxygen administration.

Sorry, I do not have more information. I have to run, but urge you to pop onto PubMed and search there. They may have some more info.