Interpreting Home Sleep Study Results

[cl981]

Hi everyone! 

I am new to the forum- I just had an at-home sleep study and received the following results, which are a bit difficult to follow at a few points. 
I have been suffering from allergies/sinus issues which are worsened when I lay down to sleep at night. I am very prone to nasal congestion and frequently have a "stuffy nose." I had several occurrences where I woke up feeling like I had been holding my breath. I wasn't gasping or coughing and it was always related to sinus issues because I would awaken with a stuffy nose and still couldn't breathe well, even when I had gotten out of bed. 

I also want to mention that I didn't sleep well any of the 3 nights of home-testing due to my husband snoring, my child coming into my room durin the night, and just generally not being comfortable wearing the plastic nose breath sensor, chest clip, etc.  I was also recovering from a sinus infection at the time of the test and I do suffer from anxiety (I was feeling anxious about the test and didn't feel that I slept well during the test because of this)... I have since recovered from the sinus infection and do not have issues with daytime sleepiness or other symptoms associated with sleep apnea- I feel pretty well rested when I wake up each day...

I am a 36 year old female non-smoker with normal blood pressure;  I am 5'3,  119 lbs   BMI: 21.1

My results were: 
Total recorded sleep time was 319 minutes  - recorded oximetry time: 294 minutes

Total number of hypopneas (4%): 2
Total number of Apneas (obs and cen): 39
Average apnea (sec): 18
Apnea index (obs and cen): 7.9
Total number of Central: 34   (I didn't have electrodes during this home test, so I am not sure how "Central" would be measured here, as it is my understanding that Central Sleep Apnea is a neurological disorder...)
Apnea max dens. index (>10 min): 43.08  (not sure what this is)...
RDH (AHI, REI) 4%: 8.3   (I am not sure what the 4% means here)

Total number of hypopneas: 85
Hypopnea index: 17.3
Central Apnea index: 6.9 
RDI (AHI, REI): 25.2 

My Baseline Oximetry was 98% and I had 8 desaturations with the lowest being 93% for 6 minutes-  98% of the time, I was between 95-100.

Pulse rate: 78

Any thoughts or assistance on interpreting would be really helpful. 

Should I request an in-lab test?  I am just not sure how accurate at-home sleep tests are in full diagnosis, given my sleep disruptions due to other people in the room, sinus infection, etc. 

Thanks!

[Ron AKA]

There seems to be some numbers that really don't add up. However, I see it if you take this to be correct:

Hypopneas - 2 (a different number is given later and that is a point you should ask about. What is the right number of hypopneas?...)
Total apneas (central and obstructive) - 39
Number of centrals - 34 
Number of obstructive - 5 ( by math 39-34)
Minutes monitored - 319

The basic apnea number in my view is the AHI which is the total number of obstructive and central apneas and hypopneas divided by the number of hours monitored. It give the number of events per hour. In your case I get

(2+39)/319*60 = 7.7

Taken by itself that is not very high and if you do not have symptoms of apena may not even be treated. That is the good news. Your oxygen levels are very good too. Over 95% is considered normal. The bad news is that the apnea events are nearly all centrals. That is not so good. 

My suggestion would be to discuss your symptoms and these results with your doctor. To my non medical thinking CPAP treatment is not likely to be beneficial in your case. CPAP generally only reduces hypopneas and obstructive apnea events, not central events. It may even increase them. Perhaps your doctor will have other suggestions to reduce your central apnea events.

Now if the number of 85 hypopnea events that is given later is correct, then there may be some benefit to CPAP. That would put you in the low moderate range of apnea, and CPAP could work. 

You need to clear up what the right number of hypopneas are and the correct AHI.

Edit:
You may find this link helpful in understanding your results.

Understanding the Results of Sleep Tests

[Mogy]

One of the main problems of the home sleep test is that it doesn't determine whether you are asleep or not. Our breathing when awake is not as regular, the tester may record events that are happening when you are awake or semi conscious.
The test is more accurate if you go to sleep and stay asleep.
When transitioning between awake and asleep we can get what some people call sleep/wake junk. A post by Robysue:

http://www.apneaboard.com/forums/Thread-...-breathing

As Ron said, some of the numbers don't add up from your test. Sometimes they break up the test between supine sleep and side sleeping.
I would suggest another home test where you have fewer distractions in your sleep. Sleeping in a lab can be fairly difficult.

[cl981]

Thank you, both!

I agree, the numbers also didn't seem to make sense to me. I have a message in to the Doctor to receive clarification and I hope to take another test (while not having a sinus infection this time). 

I also didn't understand how the Home Test could determine when I was awake or asleep since I seemed to lie awake quite a bit during the recordings... I also had a number of "sleep disturbances" due to outside factors. I was pretty nervous about having to take the test (so my shallow breathing/hypopneas may have been while I was awake). 

I didn't use electrodes to measure brain activity during this Home Test, so I am not sure how a home test can identify "central" vs. obstructive- my understanding is that Central apnea events are neurological issues that would be detected from a brain activity metric (is that correct?)... the whole reason I asked for this study was due to lessened sleep from what seemed to be congestion/sinus and allergy issues. I only seem to have sleep issues (that I am aware of) when I experience sinus problems, but weather pattern changes this year have made my sinus issues a little worse this season. 

I don't experience excessive sleepiness during the day, but since I had heard that sinus problems can contribute to obstructive sleep apnea, I wanted to take the test. It would be ironic if I actually have more central apnea events, since the sinus/nasal congestion is what I wake up with and seems to be what keeps me from sleeping well...I have the congestion during the day as well, but it is worsened when I lay down. 

Again, I really appreciate your insight- this is all new to me and I want to be proactive about my health while getting accurate results...

Have a wonderful day!

[jaswilliams]

A central Apnes is a pause in breathing without any breathing effort so the sleep test detects a central apnea as the lack of airflow measured by the nose cannula and chest band detects your not attempting to breath if this continues for 10 seconds or more then a CA is scored.


For an OA there is no airflow but breathing effort ie the chest moves.

[cl981]

Thank you!

[Ron AKA]

I had my home test done with the Phillips Alice NightOne device, and it certainly reported central and obstructive apneas. The method of differentiation that jaswilliams describes makes a lot of sense. They also report supine and side sleeping results, which I presume came from the device on the chest. I was skeptical of the home test as well as I felt I slept no more than 3 hours of the 7 hours or so I was hooked up. They claimed I probably slept longer than that, and the results were valid. Mine came back with a total AHI of 37 and it probably is about right.