Interpreting AHI

What does it mean when the AHI number is a decimal number, like .3 or .2? I know what 1 per hour means, but, what does .3 per hr translate into?

The AHI is an index of the number of events averaged over the time you were asleep. If you have an AHI of less than 1.0, you had less than one event per hour; for example, 0.5 AHI over 2 hours sleep means you had 1 event in that time.

Are you using the (free) Sleepyhead software to monitor your progress? The Event chart will give you a graphic representation of your AHI events over the sleeping period, and this may help your understanding. Information on Sleepyhead at
https://sleep.tnet.com/resources/sleepyhead.

An AHI of less than 1.0 means your therapy is going well! Congratulations.

Jean

That makes sense. I thought it was like that.

I am registered with ResMed, so I do get a daily report that gives me a score, based on various factors, like hours, leaks, AHI, etc. I normally get very high scores, thank goodness and my AHI is normally .3. I have had zero as well. I don't think I've ever had a 1 before. Maybe, once. My study revealed hypopneas are really my issue and I wasn't a very serious case. I can't recall the details. I'll have to review some of my earlier posts around here. I think I found this site when I first started Cpap.

I keep planning to do install Sleepyhead, but, just haven't done it. It's on my to do list.

Thanks for your explanation.

SunnyBeBe wrote:That makes sense. I thought it was like that.

I am registered with ResMed, so I do get a daily report that gives me a score, based on various factors, like hours, leaks, AHI, etc. I normally get very high scores, thank goodness and my AHI is normally .3. I have had zero as well. I don't think I've ever had a 1 before. Maybe, once. My study revealed hypopneas are really my issue and I wasn't a very serious case. I can't recall the details. I'll have to review some of my earlier posts around here. I think I found this site when I first started Cpap.

I keep planning to do install Sleepyhead, but, just haven't done it. It's on my to do list.

Thanks for your explanation.

Move Sleepyhead to the top of your to due list. Jim

Remember that the calculated AHI is the total number of apnea events (of all types) divided by the hours of sleep (including the fraction of an hour). These two numbers when divided can, and usually do, lead to odd AHI numbers. A couple things to keep in mind. 1) You have no choice but to accept that your machine is counting the correct number of apnea events, which takes a little faith (in other words, you have to hope that the machine's software is counting correctly and not guessing). Being an engineer, I take the machine's count with a grain of salt, but have to assume that it is at least reasonably close. The other variable "hours of sleep" is never 100% correct since it is really just the time that the machine is "on", which has nothing to do with actually being asleep. An XPAP has no way of knowing when a person is asleep or wide awake. If you want a perfect "0" AHI, just stay awake all night you will get a zero, but may be a little tired the next day LOL. In my case, it usually takes more than 30 minutes to fall asleep, and I almost always wake up at least 45-60 minutes before I get up (and turn my APAP off). This can easily add up to a hour, usually more, of non-sleep than what the machine records, which improves my AHI number. This is easy to test. Make a bathroom run at say 5:30 AM and turn off your machine and note its calculated AHI. After returning from the bathroom, mask back up and lay awake until say 6:45 AM, again note your AHI, it will be better that the 5:30AM number. This scenario is almost always my actual sleep pattern.

The above reasons are why a sleep lab's study is much more accurate, at least for that one night. The lab's equipment knows exactly when you fall asleep and later wake up. However, once again, you have to have a little faith that their equipment can accurately keep track of the number, and type, of apnea events.

Okay. That's a lot of information. I do trust the machine and I think it must be accurate. I feel really good, unless I just have an occasional night where I wake up at 3:00 and just can't get back to sleep, but, that rarely happens. Most of the time, I feel quite rested and have actually LOST 45 pounds by choice. Just trying to clean clean, watch calories and be reasonable. I'm feeling much more energetic and have even tried on some skinny jeans!

My only real issue is that most nights, my headstrap back strap portion creeps up the back up my head. I think I have an odd shaped head. Plus, I have fine, straight hair. It causes me to awaken when that happens and it does happen several times a night. I'm not sure how to remedy that. I'm told that it's the only head strap for the nuance gel nasal pillows and I love those. If I pin it, I'm afraid it'll pull and thin my hair. If I could solve that issue, cpap would be perfect for me.

Have you tried a ponytail with the strap underneath?

SunnyBeBe wrote:My only real issue is that most nights, my headstrap back strap portion creeps up the back up my head. I think I have an odd shaped head. Plus, I have fine, straight hair. It causes me to awaken when that happens and it does happen several times a night. I'm not sure how to remedy that.

That back strap thing is a common complaint across several masks. I think part of it is the shape of the back of the head.
Some people have skulls more on the flat vs rounded shape and there's just not much there to stop the back strap from sliding upwards.

Some people have actually stuck some velcro onto the back strap so that the hooks grab the hair and help hold the strap down.
If your hair is long enough..ponytail but you might be like me and wear your hair short and no way to make a ponytail.

You might think about the velcro trick. A good number of forum members have said it works well to reduce the back strap sliding up for whatever mask they are using.

I have long, very thick straight hair. I use the Dreamwear/Swift FX/P10 and even with a ponytail all straps have had a tendency to ride up the back of my head.

I put a strip of adhesive velcro on the back straps (hook side against the hair) and put the strap under the ponytail. On freshly washed "silkier" hair days sometimes even that isn't enough (I must move a lot at night, perhaps even dancing in my sleep?..lol)...so on those nights I'll lightly spray some hair spray on the velcro to make it even more tackier. Sometimes I'll add a small flat barrette ABOVE the ponytail to help stop the migration upwards.

Congrats on the weight loss and commitment to a healthier lifestyle, including CPAP! I've been on the same journey to reverse the after-effects of last year's medical nightmare. My quick weight loss/diet changes/waaaay waaay more exercise really played havoc with my sleep stats, but it has all pretty much settled down now....it's all good! Keep it up!

Thanks to all for your comments, well wishes and suggestions. (Upthread I meant to say that I was trying to eat clean. Not clean clean.....lol. )

I do use a ponytail some of the time, (my hair is long), but, it only helps a little. It still slips up. I don't want to wear a ponytail every night, because, from what I have observed, people who pull their hair back that way on a regular basis, long term, get balding or thinning of the hair around the hairline. I'm also concerned about putting a bow there or even velcro. I'm afraid it would cause a bald spot, since it would cause a tug on the hair in that one spot long term. But, I may give it a shot anyway. Maybe, I can rig up something that won't snag it too strongly, but, yet holds it from slipping.

I will consider a bald head mask that should keep the strap from slipping. That's a unique idea. I'll look into it. Perhaps, it would put less stress on the hair. though, it might not look that romantic (I'm a lady)......lol. I'm trying to envision it now with my nasal pillow....oh my....lol.

Sometimes, I get tickled at myself. It's amazing the things we do to try to stay healthy. I am also a Type I diabetic. I got a Continuous Glucose Monitor a couple of months ago. So, I wear the sensor on my side/belly and I sleep with the transmitter on one side of the bed. My cpap on the other! It constantly measures your blood sugar levels and records it in graph form, alerts when too high or too low, around the clock. I swear, sometimes, I feel like I have no PRIVACY. My life is constantly being recorded and later reviewed. lol

Instead of a ponytail, have you tried lifting all of your hair above the strap? (or make a ponytail, put mask on, then remove ponytail holder) This works for shorter hair too.

luvsbluberries wrote:Instead of a ponytail, have you tried lifting all of your hair above the strap? (or make a ponytail, put mask on, then remove ponytail holder) This works for shorter hair too.

I haven't. I'll try it.

[quote="luvsbluberries"]Instead of a ponytail, have you tried lifting all of your hair above the strap? (or make a ponytail, put mask on, then remove ponytail holder) This works for shorter hair too.[/quote]


THANK YOU! This method worked for me. I didn't have any slippage and thus, didn't awake at all, that I recall, last night. What a relief!

Just another followup. This method of putting the head strap under the hair worked again last night. I got about 8 and 1/2 hours of sleep last night! I am NOT waking up with the strap creeping. I'm so happy!

I am reviving this thread because I have two new questions. It's been a while since I've posted around here. I hope someone can help me.

I've been reading on various threads, but can someone direct me to a thread that will give me step by step instruction on Oscar process? I have installed it on my PC, but can't seem to import my SD card to it. ( I am back on cpap ResMed AirSense 10 Autoset with nasal pillows. Previously, I checked my progress with ResMed.) I am now off the grid, but I would like to see my info in writing, though, I know it's going very well. Still, I want to see it. I had some down time due to eye issues and a couple of eye surgeries. (Do I need a special reader on my PC. When I try to view SD card info, it says I need one.)

Second issue, does anyone know if there is a mask or pillow that sends the air out the top of the head or on the back of the head? Even though the nasal pillows disburse a small amount of air from the front, it still bothers my eyes. I have severe dry eye and cornea issues. So, when I recently resumed cpap therapy, I wore special night goggles to protect my eyes. Apparently, there is a leak in my goggle seal, because my eyes are once again starting to get irritated. No problem with leak in nasal pillows. It has taken me over a year to get this improvement in my eyes and now this! It's heartbreaking. So, I'm using nighttime ointment, goggles and humid air on cpap. Any other suggestions would be appreciated. I've read this is quite common. Oh, I take levothyroxine, zetia, vitamin D, fish oil, cranberry pills and Novolog insulin by pump.

I think that's why I'm having trouble focusing on the Oscar project. The pain is quite distracting. Thanks for any help.