recent sleep study results

[Jst617]

I've been on a cpap now for a couple of years.....lately things havent been well, (several naps during the day, not feeling rested) so doctor ordered a sleep study, It was supposed to be a split study, which started without the cpap, but then they were supposed to wake me up to put my mask on, but that never happened she said something about I never got to a certain stage. Anyway, I have the results now, kinda concerned about my O2 levels, the mean was 94 but it got as low as 74......if I dont have sleep apena, why is my oxygen so low? Camn someone explain this line to me:
If the patient still shows signs and symptoms of uncontrolled sleep apnea on current therapy, positive airway presuure retitration is recommemded? 

What doe retitration mean?

[Crimson Nape]

It means that if your current pressure levels are not abating your apnea, your pressures will need to be changed.
- Red