Sats are lowering

Daylen is officially 2 years post fontan and everything has looked beautiful from his color to his oxygen and his echos. However, the last 2 months he has been looking purple in the hands and feet so I had his pediatrician check his oxygen sat for me and he was hanging out at 81-83%. This alarmed us a little because 9 months ago at his cardio visit he was 94 which is usually where he hangs out at. I haven't noticed any decreased activity or other symptoms with these lower numbers. 

During Daylens fontan, they decided to fenestrate him along with fixing his stenosis problem in his pulmonary arteries. They were previously widened and patched but that failed to work so the next option was to run conduit for the extra oxygen flow. 

We have an echo scheduled for the 21st so hopefully that will give us answers on why he has dropped. Since his last surgery he was only gained 8 lbs and has grown 4 inches which isn't a huge growth spurt considering his fontan has to take him into adulthood. 

No fluid either from what the ped said when she listened to him. <3