I have a question about a patient that had a normal oxygen saturation in the am taken by the tech. In the after noon it showed an oxgen sat of 82% pt asymptomatic all other vs wnl RR 16. Pt had acrylic nails and painted. I rechecked took nail polish off. Monitor was bouncing around then hit 88 still pt denied sob lungs clear rr16. The pt was on a morphine pca but not at all drowsy. S/p surgery pt pod#2. Put pt on 2l o2 anyway head up. Called respiratory thinking equipment not reading right. Resp equipment showed same and agbs showed 74%. Ended up transferring pt to another unit but I'm confounded on what might have happened. Tele even showed sr??????