I just learned something. I am in hospital with rhinovirus (LOL) aka common cold and mild Stephococsus (sp?) Aureus pneumonia and at first had a bit of supp oxygen. The doctors told me that with any kind of COPD you should keep your oxygen level to around 88 to 95 because otherwise you could get some kind of acidosis which would show up in blood gases and in blood tests that show anion levels etc. I never knew this before so you have to be very careful when Doctors just willy nilly put you on oxygen in the ER etc. Always carry your own 02 monitor so you can double check yourself. You might want to google this topic to read more about it. Has anyone else heard this?