Why Did My AHI Score Go Up?
I’ve been on CPAP therapy now for over two months and as I’ve mentioned elsewhere, my AHI Score went from the mid-70s during my sleep study to somewhere in the five to seven range while using my CPAP machine. For the second time though in the last month I’ve had a really strange anomaly – my AHI score jumped up to over 13. The first time it happened my score went from 6.4 to 15.3 in one night and I was a little bit concerned. Was I going to be tired that day? Is this the new normal for me now? Then the other night, I came home from work and checked my Icon+ CPAP Machine and it showed that the previous night’s AHI was 13.1. I checked the leak numbers and my SensAwake figure and nothing seemed amiss. I just rolled the shoulders and carried on. The most important thing that I’ve discovered with trying to overcome my obstructive sleep apnea is to focus on how I feel rather than the statistics. When I first went got my CPAP machine I would worry about the results every single day, hoping that my “numbers were good”. The truth of the matter is, I felt great, I wasn’t tired, no more inadvertent naps or falling asleep in front of the TV at 7:30 at night.
Checking Your Sleep Data
One of the idiosyncrasies of my Icon+ machine is that it doesn’t write or update your data on the USB stick until noon each day. That makes some sense when you think about it because Fisher and Paykel are trying to ensure that if you have multiple sleep sessions during a 24 hour period, they capture the entire day and are able to calculate the figures for the full 24 hour period. On the other hand, that means I can’t check my sleep data before I go to work or when I first wake up in the morning. And you know what? I actually like that. I really think that if I had the ability to roll over in the morning and bring up my AHI numbers on the display, I’d be thinking about it all day and I think it would have some kind of impact on the way I felt that day. Without knowing the numbers, I just get on with it and check when I get home from work. I suppose I still haven’t answered the question about why the numbers on a couple of occasions suddenly spike up? Well, I have a pet theory about this.
The SensAwake Feature
I think the spike is down to the “auto” algorithms in the machine. The SensAwake features and the auto-titration elements of the CPAP machine adjust the flow of air based on “feedback” from your breathing patterns. My feeling is that maybe I’m just sleeping more lightly or something and am having more hypopneas rather than apneas and therefore the numbers might be elevated. This potentially could wreak havoc on the machine’s algorithms which try and make the airflow comfortable by making small adjustments rather than massive increases in titration when you start having events. I’m going to look at the data a bit more closely this week. The good folks at Fisher & Paykel don’t make their InfoSmart software available directly to patients, so I’m not able to see the detailed sleep data easily. I’ll probably spend an hour this week looking at the open source, SleepyHead software and see what that can tell me. Hopefully, some more detailed data will either confirm my theory or give me more insights. Either way, I’m not too concerned about it because like I said, I feel so much better now that my odd AHI scores are just a curiosity piece for me more than anything else.