At an altitude of 5,280 feet the normal oxygen saturation should be 92% or greater and at sea level, 94% or greater. If, however you are having a lot of pain that could restrict your breathing and/or are not yet fully ambulatory, your levels might be in the mid to high 80% range. That would not be normal but would not be uncommon. At that point you might benefit from the administration of supplemental oxygen. With lower levels than the upper 80%, your doctor should be checking to see if you have pneumonia or if your lungs are not fully expanded.