My first week as a hosehead

[yarrow]

Here's an email I sent to various friends who'd had pieces of my story so far. It's way long, and addressed to people who've barely heard of sleep apnea, so it explains things that folks around here don't need explained. But I thought it might be of interest anyway.

Since February I've had two health goals: to lose weight, and to improve my sleep. The weight had been coming off slowly and steadily, but the sleep just didn't want to follow -- and even when I'd get 9 or 10 hours, I didn't feel much more rested. Sometime around the last week of April the sleep situation got abruptly worse -- I felt incredibly tired, all day every day. I'd just doubled my meds for high blood pressure, but cutting back on them didn't seem to help. I went back to my primary care physician, who ordered a lot of blood tests, but told me the most likely explanation was sleep apnea: the airways of my throat would relax and close, stopping my breath for 10 seconds or longer, until I aroused enough to tense them again and breath. This is something that can happen many times an hour -- it doesn't actually wake you up, but it does make sleep unrefreshing.

As it happens, my doctor was right, and I was on my way to becoming a hosehead.

First someone from a home health agency came out and showed me how to use an oximeter, which clips onto your finger and records the oxygen saturation of your blood when you sleep. The normal range is 97% to 99%; mine went down at points to 85%. About a week later I went to a sleep clinic for an overnight study. They told me I had an AHI of 20.5, which means that I stopped breathing (apnea) or almost stopped breathing (hypopnea) 20 times an hour -- moderate sleep apnea. A week later I went back for another overnight, to titrate the machine (determine how much pressure I needed). I didn't sleep much either night -- too many wires and belts attached to too many parts of my body for real comfort. A week and a half after the titration study I finally got my CPAP machine -- CPAP for continuous positive airway pressure. The machine blows air into a mask which you wear on your face, and the increased pressure keeps your airways open. (And the mask is attached to the machine via a long hose -- thus "hosehead".)

The machine I got is actually an APAP -- adjustable positive airway pressure, able to vary its pressure automatically depending on what (it thinks) I need. But to start out they simply set it to a constant pressure of 9 cm (9 centimeters of water -- who comes up with these medical measurement units!?)

Thursday, AHI 14.6: I spent about 5 and a half hours on the machine, about four of those sleeping. Overall AHI was 14.6 -- not that much better. My machine records detailed data on an SD card, and there's an open-source program, SleepyHead, that will read it. Looking at the graphs, I saw that I had some totally clear periods alternating with periods of really frequent apneas -- once a minute or slightly more. And looking in even more detail, I saw that graphs looked an awful lot like the graphs of Cheyne-Stokes breathing in Wikipedia and other places on the web. Furthmore, the machine thought most of them were central apneas rather than obstructive apneas. An obstructive apnea is the kind I described above, where your airways close and you can't breath even though you're trying. Central apneas happen because for some reason your body decides not even to make the attempt. Cheyne-Stokes breathing is one kind of central apnea, and googling for "Cheyne-Stokes" is downright scary: it's strongly associated with heart failure and stroke. But it's also something that happens to some of us initially diagnosed with obstructive sleep apnea -- the CPAP or APAP machine clears out the obstructive events, which paradoxically leaves you vulnerable to a cyclic breathing pattern where the carbon dioxide in your blood goes so low that your body stops breathing; your blood CO2 finally rises enough that you breathe; you breathe so efficiently that you lower your blood CO2 level below the point that triggers breathing; you stop breathing; and so on.

Friday, AHI 11.3: Friday, as an experiment, I took Afrin to clear my nose of allergies. I had one obstructive apnea, in contrast to Thursday's twenty. (And discontinued the Afrin -- I'm definitely scared of the rebound that can happen if you use it for more than three days!). A bit under 4 hours on the machine, maybe three hours' sleep -- I kept waking up with a dry mouth. I turned the machine's humidifier up and up, and eventually decided it must have run out of water. But when I got up to refill it, it had a perfectly adequate amount of water. Some investigation on cpaptalk.com made me realize I'd learned to breath through my mouth in just two nights! (And short ones at that. ^_^) I hadn't done that in the sleep lab and had been hoping I was immune.

The cure for this is either a full-face mask (which I didn't have -- they're hard to make work with beards); or a chin strap to keep your mouth closed. I didn't have a chin strap either, and my bite is so terrible I hated the thought of something forcing my teeth together; but needs must, so I searched cpaptalk for "improvised chin strap", and lucked into SleepingUgly's description of a different mouth sealing method -- a self-adhesive Ace bandage wrapped horizontally around your head, like a blindfold for the mouth.

After that I took a late-morning nap, two hours on the machine. I wondered if the extra pressure was making me hyperventilate, causing the Cheyne-Stokes, so in the afternoon I took an hour's nap with the machine set to ramp up from 4 cm to 9 cm over 45 minutes -- no apneas at all during that period.

Saturday, AHI 16.0: I kept the 45-minute ramp-up. Again, no apneas during the ramp-up periods -- but lots of Cheyne-Stokes breathing after ramp-up, in periods of up to an hour. Google found a site that gave the secret to unlocking the clinician settings on my machine, and I set the pressure to float between 4cm and 9cm. Took an afternoon nap, a bit over an hour's sleep with one 3-minute episode of Cheyne-Stokes, AHI of 3.9 for the nap.

Sunday, AHI 7.3: Scattered sleep, about four and a half hours apnea-free (or almost free), another hour and a bit at 10 AHI, and twenty minutes of Cheyne-Stokes apnea-per-minute breathing.

Monday, AHI 2.3: No apneas to speak of! Yay! No sleep to speak of! Boo! -- Well, about four hours of sleep (out of six and a half on the machine). Really tired.

Tuesday, AHI 4.8: Another day relatively clear of apneas, but again only four hour's sleep.

Friday, on the advice of Pugsy from cpaptalk.com, I'd asked to have my sleep study mailed to me. When it came, I learned that in the titration study my apneas had already mostly been central. "Consider a repeat titration study if symptoms persist. ASV might need to be considered if central apneas are persistent with CPAP".

ASV stands for "adaptive servo-ventilation". The usual CPAP pressure is high enough to keep your airways open, which prevents obstructive but not central apneas. An ASV machine, when it detects Cheyne-Stokes breathing, ramps up the pressure enough to actually force you to breathe -- sort of like mouth-to-mouth resuscitation, only this is mask-to-nose.

Getting the study was reassuring in one way -- my interpretation of the readings agreed with the sleep center's. And it was infuriating: folks like me, who develop central apneas once the obstructive apneas are dealt with, often see the centrals go away in a month or two. But that's a month or two of a very rough ride. No one bothered to tell me that it would likely be difficult for some time, that the difficulties would quite likely go away, and that if they didn't there was a plan B. My geeky fascination with electronic toys showed me the central apneas; Google and the folks on cpaptalk.com told me what they meant and what to expect; but this kind of patient non-education is one reason why between 40 and 70 percent of people started on CPAP eventually stop.

Also, the 20.5 figure from the diagnostic study wasn't AHI, but RDI -- everything covered by AHI plus other respiratory-event-related arousals, semi-awakenings caused by breathing problems that aren't quite apneas or even hypopneas. The AHI was 14.1 -- so my first and third nights at home with CPAP were actually slightly worse than the sleep study night without CPAP.

Wednesday, AHI 4.7: First CPAP night with a semi-decent amount of sleep -- 9 hours in bed with 75 minutes up in the middle of the night, just under eight hours on the machine, probably a bit under 7 hours sleep. Felt half-way decent most of the day, very tired from 4pm to about 8pm, then annoyingly perky as I tried to get myself to bed. This is more or less the pattern I've been in for some years, and had been trying to reverse by better sleep habits when whatever happened in late April happened -- when the 4pm crash started coming at 10am.

Thursday, AHI 11.0: Oops! I tried setting my pressure lower, to avoid central apneas, and got lots of obstructive apneas instead. The 10am crash came back with a vengence. I was working at home Friday, so I set the pressure back up, took an afternoon nap (only one apnea!), and put in for some sick leave.

Friday, AHI 7.9: Disappointingly high AHI, eight hours of apparently solid sleep, but periods of Cheyne-Stokes breathing totaling an hour and a half scattered through it. I seem to be back at pre-April levels of tiredness -- a definite improvement over April and May, but there's still a long way to go. This is definitely frustrating ("What do we want? Sleep! When do we want it? Last night!"). Still, there's a part of me in geek heaven -- data! graphs! open-source programs! debugging my own breathing! (And even that part of me would gladly forgo the techno-euphoria in return for a nice boring reliable solution.)

[HoseCrusher]

Excellent progress so far. Keep up the good work.

[Suzjohnson]

I think you are doing extremely well for only 1 week! Obviously you understand the mechanics of what is happening and are willing to do what it takes to be successful. It might be beneficial to stay with settings that appear to work for a week or so to have a clearer picture of what that setting is doing for you. I like the way you are recording everything diary style. Much more interesting to read than my spreadsheet.

Suz

[yarrow]

I think you are doing extremely well for only 1 week! Obviously you understand the mechanics of what is happening and are willing to do what it takes to be successful.

Thanks! It helps that I never found the mask worse than annoying, and seem to have learned how to sleep through, more or less. Last night I woke up four or five times, I think, but went right back to sleep. In the long run I want to not wake up -- but for now, "right back to sleep" is a good second best.

It might be beneficial to stay with settings that appear to work for a week or so to have a clearer picture of what that setting is doing for you.

Yes, I think you're right. My current plan is to keep my current 4cm to 9cm setting for a week, then start raising the lower limit toward 9cm. My prescription is straight CPAP at 9cm, which I abandoned after three days because of all the centrals; but last night my median pressure was 8.28cm, so I may be able to go back up to straight 9cm. (I'd like to come to the sleep doc having tried his prescription for at least a week!) After a week of 9cm, if I'm still having centrals, I'll try turning on EPR to see if that helps or hurts.

[insylem]

How do you know when you go into Cheyne-Stokes?
How do you know when you have a central?

I know what central apnea is
I dont fully understand Cheyne-Stokes though, I googledit but wikipedia's artical is way too much and in depth for me to understand.

Glad your makeing it work though!

[yarrow]

How do you know when you go into Cheyne-Stokes?
How do you know when you have a central?

To tackle the second question first -- the S9 tells me when it thinks an apnea is a central -- it uses small pressure pulses and sees if it gets a response. The gold standard comes from the belts around your chest and stomach in the PSG, so I take the S9's guess with a grain of salt.

To answer the first question, the pattern I see in my breathing looks like Cheyne-Stokes -- and since I'm not a sleep doctor (nor any other kind!), I take my guess with a grain of salt too. But it sure looks like it. Here's a pic:



I compare that with the examples from examples from Wikipedia http://en.wikipedia.org/wiki/Cheyne-Stokes_respiration or ResMed http://www.resmed.com/us/clinicians/abo ... ation.html. Basically, that pattern of an apnea somewhere around once a minute, with the volume rising after one apnea and dwindling away again before the next is what makes me think it's Cheyne-Stokes.

[insylem]

Oh okay cool.
I dont think my machine gives me a flow rate graph. But thanks

[Pugsy]

I dont think my machine gives me a flow rate graph.

Correct. Your machine is the model prior to the PR S1 model and the M series machines don't tell us if an event is clear airway (central) or not and they don't give any flow data to evaluate the breaths. Old technology vs new technology thing.

[fredmertz]

I know the temptation is significant, but you seem to be doing an awful lot of self-diagnosing for someone with absolutely no medical training and no history of being on CPAP. Are you sure this is wise? Google is not a doctor!

[yarrow]

I know the temptation is significant, but you seem to be doing an awful lot of self-diagnosing for someone with absolutely no medical training and no history of being on CPAP. Are you sure this is wise? Google is not a doctor!

Until I finally meet my sleep doctor, Google is better than no information. I understand that 40 to 60 percent of people with CPAP machines don't use them. So far, I've been using mine.

[fredmertz]

Until I finally meet my sleep doctor, Google is better than no information. I understand that 40 to 60 percent of people with CPAP machines don't use them. So far, I've been using mine.

We'll have to agree to disagree. Tinkering with your settings before you are halfway through your first week week of therapy because you think you are seeing something that resembles something that you saw on a wikipedia page is worse than no information.

I too found the service menu on my CPAP in the first few days and I too thought I could tinker with it successfully. I switched it to APAP because APAP machines are more advanced and that has to be better right? I switched the settings on a near-daily basis because I wanted the lowest AHI possible and getting to 6 was just not good enough. After a week of tinkering I realized that a doctor with actual medical training saw my results and thought CPAP at 11 was the best option. I switched it back and 2 weeks later I am getting consistent readings around 2.0.

You wouldn't open up the hood of a new car and start tinkering with it after three days of use that didn't meet your expectations, so putz around with something that is so much more important?