Why is oxygen supplementation not suppose to be dialed up higher, with an obstructive lung disease patient?

Can stop breathing: In the late stages of emphysema or copd, patients do not respond normally to stimuli that make normal patients breathe. They only keep breathing in response to low oxygen in their bloodstreams. If they are given too much oxygen, their systems think that they don't need to breathe and they can actually breathe less or stop breathing. This is a rare problem. Oxygen helps most emphysema patients.

Small minority: Normally, the level of carbon dioxide in the blood is what determines the drive to breathe. In some patients with copd, however, their drive to breathe becomes controlled by oxygen rather than carbon dioxide. In those patients, giving too much oxygen can be very deadly, causing them to actually stop breathing. It is hard to tell who will be like this. So, use the least amount of oxygen needed.

In some patients: In a small number of very severe COPD patients, the drive to breathe is based on oxygen rather than carbon dioxide, which is what is normal. Thus, if you dial up the oxygen too much for these patients, it can actually cause them to stop breathing. Usually, the level of oxygen required to keep the saturation above 88% is adequate.