hello, my brother in law was DX in Sept with small cell lung CA. He had a reoccurence after initial Chemo and is now on Topectan. Today, his O2 sat rate dropped to 85%. They have ordered O2 at home now. What might be the reason for this new development. I am a nurse and I know his DX is EXTENSIVE. He also has a tumor in the head of his pancreas and mets to his adrenal gland. What might be next? Could this new development be paraneoplastic syndrome? thank you, Jimmy Trusso, R.N. in Cleveland