Too much of a good thing

This morning sweet Mason had a surprise ready for Mommy. When I arrived his chest tube had been removed. At least the large chest tube on his right side, the one on the left side will remain until the drainage has been stopped. The other issue we are watching is the level of his oxygen saturation. Most of us have oxygen saturation levels of 95-100%. Little Mason requires his level to be between 75-85%. His current levels have fluctuated but are definitely above 85%-meaning too much blood is flowing to his lungs and not enough to other parts of his body. When I brought up my concerns to the RN she said they had in fact been watching this for the past couple of days and were going to give him Captopril to see if this would lower his blood pressure-in turn this would hopefully lower his oxygen saturation levels. I pray that they are able to stabilize with the medication without lowering his pressure too much. It just doesn't seem right-having too much of a good thing! Just one more hurdle this tough boy will get over-I have faith.