Help me understand

[Senci]

Hello, I need your help and expertise as I don’t understand this. I apologize in advance for the long text.
Last year in November, I underwent a sleep study, and below are the results:
Sleep Study (November last year):

• Recording time (hours and minutes): 6:44 (I know I only slept for 3 hours, so how can it record 6:44? Does the device also record the time when I’m trying to fall asleep?)
  
• Apnea-Hypopnea Index (AHI): 6
  
• AHI in the supine position: 9
  
• AHI in positions other than supine: 2
  
• % of recording in the supine position: 50%
  
• ODI3: 6
  
• Average saturation: 95%
  
• Lowest SaO₂: 89%
  
• Snore Index: 9
  
• Total number of respiratory episodes: 37
  
• Obstructive apneas: 4
  
• Mixed apneas: 6
  
• Central apneas: 2
  
• Hypopneas: 25
  

Assessment:
Findings indicate mild obstructive sleep apnea.
I was given an oral appliance, and a new sleep study was done in November this year. Below are the results:
Sleep Study (November this year):

• Recording time (hours and minutes): 6:01 (Again, I only slept for 4 hours. How can it record 6:01?)
  
• Apnea-Hypopnea Index (AHI): 2
  
• AHI in the supine position: 4
  
• AHI in positions other than supine: 0
  
• % of recording in the supine position: 40%
  
• ODI3: 2
  
• Average saturation: 95%
  
• Lowest SaO₂: 82%
  
• Snore Index: 9
  
• Total number of respiratory episodes: 10
  
• Obstructive apneas: 0
  
• Mixed apneas: 0
  
• Central apneas: 4
  
• Hypopneas: 6
  

Assessment:
With the oral appliance, AHI < 5, thus no findings indicative of obstructive sleep apnea.

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Here is what I don’t understand:

1. When I compare the results from the first sleep study to the second one, the lowest SaO₂ during the second study (with the oral appliance) was 82%, while during the first study (without the oral appliance) it was 89%.
   • Why is my oxygen saturation worse with the oral appliance than without?
     
   • Could this be caused by something else? Is 82% considered low?
     
   
   
2. Could it have anything to do with the "snore index"? I don’t understand what a snore index of 9 means.
   
3. I had more central apneas with the oral appliance than without. From what I’ve read, CPAP is not the best treatment for central apneas, but BiPAP might be. Is that correct?
   
4. I haven’t spoken to the doctor yet, but I want to prepare and understand these results before the doctor calls.
   

[*]I am extremely tired. I’ve had to reduce my work hours because of the fatigue. I sleep for two hours after work every day and still have no trouble falling asleep at night. I need between 10 and 14 hours of sleep to feel somewhat rested. It’s a paralyzing fatigue.
I humbly ask for help in understanding these results.

[G. Szabo]

The reports show you can resolve your sleeping problems by enforcing side sleeping with the oral insert. 

Anything below 90% saturation should be investigated. 82% is extremely low. However, the lowest saturation figure alone is not very informative. It matters how long you stay at the low level, which is expressed as a percentage of your sleep time. Your average saturation is good. You probably had some obstructions when your saturation dropped briefly during the supine position. 

You might want to purchase an oxygen saturation monitor capable of downloading the result every morning to see your saturation when you sleep strictly on your side. You can find some bargains on Amazon when you do not insist on the fancy ring type of sensor and accept a clip on your nail. 

A positional therapy might be your solution.

[Senci]

Thank you so much for your response! I don’t know how long (in terms of time) I was at 82% oxygen saturation because I didn’t receive information about how long the breathing interruptions lasted. Do you have any recommendations for an oxygen saturation monitor? This is a completely new world for me, and I’m trying to understand why I feel so tired.

[Deborah K.]

You need to download and use Oscar, our free apnea reporting program that creates great charts that we can interpret for you to help with your therapy.  You can download and learn about Oscar at the top of any page, in the black ribbon.

[G. Szabo]

I believe the above comment was intended for someone with a CPAP instrument. In this case, there is none yet. 

As for the oxygen sensor, this forum discusses the different sensors and their features quite a bit. You should do some searching.

[Deborah K.]

You're right. I didn't notice that she has no machine yet.