Interpret newbie's oximeter results

Hi,

I'm a 63 year old male living in Toronto. I'm 5'11, weight 188, bodyfat 31%, neck size 17". I don't have high blood pressure or diabetes. I don't work out enough, but eat a reasonably healthy diet. I normally sleep from 10:30 pm through to 6 am, waking once to pee if I've had any liquids before bed. I've snored for decades. I fall asleep on my side, but always wake up on my back. I've tried tennis balls (etc) in my t-shirt, but it just wakes me up when I try to roll over. I've taped my mouth with paper tape which surprisingly left me less congested in the morning, but I still snore loudly. I have a humidifier and hepa air filter in my bedroom. My snorelab average is 33 which is a bit louder than the average snorelab user. Fortunately my girlfriend doesn't mind wearing ear plugs. About 2 months ago, I started waking up around 3:15 and have had difficulty getting back to sleep. My family doctor described this as 'sleep maintenance insomnia'. He suggested 5 mg melatonin, 1 hour before bed to re-align my circadian rhythm. This made me even sleepier at bedtime, but I've never had trouble falling asleep. I still woke up at 3:15. I then tried GABA and a brief trial with sleeping pills, but I still wake up at 3:15 (plus or minus 15 minutes). The snorelab recording shows pauses in my breathing and some snorting sounds. It shows a lot of variation in my snoring sounds over the course of the night, not a consistent pattern. Now I'm wondering if my insomnia might be related to sleep apnea.

I got an oximeter from walmart.ca (Torontek b400, equal to Contec CMS50F, firmware version 6.1). I've used it for 3 nights now. Similar results each night with lots of events. I can get the data into SPo2 Assistant and Sleepyhead. I'm seeing my family doctor on Thursday and am thinking I should request a sleep study rather than pursing other options like an oral appliance.

I've attached some recent results. I'd appreciate some help interpreting this. All the desaturation events makes me think that, yes I probably have sleep apnea and should have a sleep study to confirm and quantify it. My family doctor will have a recommendation for where to go in Toronto (I work downtown and live in North Toronto). I'm thinking I should go to a level 1 facility and was thinking the hospital affiliated sleep labs at St. Mikes, TGH or Sunnybrook might be best.

Thanks for your advice,

John

JohnTor wrote: ↑

Sat Dec 15, 2018 12:50 pm

About 2 months ago, I started waking up around 3:15 and have had difficulty getting back to sleep.

A good rule of thumb is 90% of problems sleeping are due to sleep-disordered breathing. Given your snoring and snorting, you are at about 99%. A CPAP would be a very good thing for you.

Welcome to the club!

as you Getting desaturation below the red line 88% when sleeping you have some form of sleep apnoea that’s causing disrupted sleep. You should get your dr to refere you for a sleep study you have a number if key indicators, disrupted sleep, o2 desats, snoring and obstructed breathing.

Thanks for your advice. I will get a referral for a sleep study this week.

In the meantime, I'm going to set the alarm on my oximeter to beep when my O2 drops really low. I figure it's better to wake up than to continue like that.

john

Here's another oximeter chart I'm trying to interpret. It's for my 13 year old daughter. The recording only covers about 4 hours before the sensor fell off her finger, but there is a clear desaturation event. Should I be worried about this? Should I get her to record a few more nights? She doesn't snore but does breathe through her mouth, a habit she developed after a few years of bad allergies which have since subsided. She has tried taping her mouth at bed time and likes it because she doesn't wake with a dry throat when she tapes.

John, I am not sure what was going on at about 1:20 on your chart but at about 2:40 you will notice that your desaturation was accompanied by an increase in heart rate. I wouldn't rule out the first one but the second one is more significant.

Your daughter is showing a similar pattern. O2 levels drop kicking in an increase in heart rate.

The wild card in all of this is finger movement inside the oximeter. This often is flagged as artifacts but sometimes it isn't.

More data helps to give a better picture. Be sure to print out your graphs and bring them to you doctors appointment.

Another thing you can do is bring your oximeter to the doctors appointment to make sure it is accurate.

Thanks for these thoughts. I will ask my daughter to try this for a few more nights to get more data.

I've wondered about the accuracy of my oximeter (cms50f). I sometimes put my hands behind my head when I'm sleeping and that gives me a desat. I've turned the alarm on at 88% which is training me not to do that. My daughter has small fingers so movement inside the sensor might distort her readings. So even an accurate oximeter can give distorted results.

Aside from these types of errors, I come across a piece of research that the Contec devices are quite accurate with errors less than 3% (usually at the lower saturations).

http://www.lifebox.org/wp-content/uploa ... meters.pdf

Neverthless, I've ordered a new cms50i from aliexpress. I'll wear both of them for a few nights to see if there is a material difference. Then I plan to use the 50i going forward. I like that it stores several days data so I can do all my downloads to sleepyhead on Saturday morning rather than every morning.

I'll rotate my 50f though each of my family members to see if they stay adequately oxygenated while they sleep. No one snores as bad as I did.

I've only been on Apap for about 10 days and my sleep quality is greatly improved.

JohnTor wrote: ↑

Fri Jan 04, 2019 5:52 am

I've wondered about the accuracy of my oximeter (cms50f). I sometimes put my hands behind my head when I'm sleeping and that gives me a desat. I've turned the alarm on at 88% which is training me not to do that

It's accurate, as long as the sensor is on your finger (there's a reason that they tape the sensors on in the hospital.. well, two, first, the tape on sensors are, by their very nature, cheap (not that they pass that on to us) and disposable, and second, they don't move around on your finger and cause motion artifacts.

I'm doubtful that putting your arms behind your head actually causes desats, it may cause errors in the reading. Try putting the sensor on a toe or something. It'd be better if your sleep weren't disturbed by alarms.