Tuesday, November 28, 2006

Sleep Apnea

Sleep Apnea

One of the topics that a lot of fat folks are or should be interested in is sleep apnea. More properly known as obstructive sleep apnea(to distinguish it from central sleep apnea), this condition is one which afflicts a surprisingly large number of folks in all sizes and shapes who share a shocking characteristic. They don’t know they have it.

Obstructive Sleep Apnea is a condition which develops when the body is sleeping in which the airway is blocked, generally in the soft tissues around the back of the throat. As the body falls asleep there are a number of physiological changes which take place, including the usual stuff with different levels of sleep and relaxation of the non-autonomic muscles(anything other than the muscles which keep the heart pumping and the lungs breathing in the diaphragm, for example). So, your arms, legs, gluteus maximus and, more relevantly, the muscles around your face and neck tend to relax(again, in technical terms, lose tone). With the muscles of your arms and legs the relaxation tends to have no real impact on your breathing, but, as the muscles surrounding your upper airway relax, the soft tissues inside your throat lose tone and tend to sag. As you get older, aging through the 30s and 40s etc. your muscles generally lose tone and sag even more. For people with sleep apnea, at some point, the tissues in the airway sag together and meet, blocking the airway so that air/oxygen neither enter the lungs nor leave the lungs as the diaphragm does its breathing thing. The muscles of the diaphragm move to expand the lungs so that air is generally sucked into them and move again to reduce the lungs expelling the oxygen depleted air out of the lungs so it can be replaced with fresh oxygenated air. However, when the soft tissues block the airway the diaphragm does its thing, but no air passes the blockage. As expected, this isn’t a good thing.

Since the diaphragm has no idea whether air is coming in or going out it just blithely does its job without fail until a sensor in the brain detects that the oxygen content in the blood in the brain has dropped below some level and activates the fight/flight reflex by pumping adrenalin into the blood(as it figures some serious shit is going down and it better give the body the power to deal with it tout suite). When the adrenalin hits the blood stream(which just takes a few seconds), this jolts the system and the body wakes up. When the body wakes up this tones the muscles which come to attention, and magically, the muscles in the airway tone, the blockage disappears and fresh air can come into the lungs. However, as soon as the body then senses that the oxygen level in the brain has returned to a safer level, it shuts off the adrenalin jolt, and the body slides back to sleep. Unfortunately, as the body returns to sleep, the airway blockage reestablishes itself as the soft tissues kiss each other again as the tone in the muscles of the airway fades with the return to sleep. And, when the oxygen level drops below some point the cycle repeats itself, with the body rousing itself in a shock. Now, if this were to happen to you fresh off a good night’s sleep you would sense you were rudely awoken and take some time to fall back asleep. But, sleep apnea is a more insidious thief stealing your rest slowly and surely so that by the time it has really taken hold you rarely get more than a minute or a few at most between these intervals. Over a period of days, months and even years of this sort of activity, which tends to get worse with time, rather than better(if untreated), your body gets run down and you enter a state of permanent sleep deprivation. In this state, when the body wakes up to get some precious oxygen into the blood and brain, the brain is so tired that it falls right back asleep without bothering to register that its been awoken. To give you a sense of the magnitude of this scenario, when I was first diagnosed with sleep apnea, in an 8 hour night of “sleep” they counted 480 apnea events, or, for you mathematically challenged readers… an average of one every minute for the full 8 hours. No wonder that at the time I was always tired, and would doze off whenever I’d sit down somewhere, whether in front of the TV or reading a book or even during a meeting.

But, that’s getting ahead of the story a bit. Because sleep apnea is something which only happens when you’re sleeping, its extraordinarily difficult for people to observe or diagnose by themselves. One way of diagnosing it is to determine if you snore a lot. Not everyone who snores has sleep apnea, but everyone who has sleep apnea snores. Again, most people deny they snore. But, if you sleep with someone or in their vicinity, or if when you’ve dozed off on the train or in a public place people tell you that you have been sawing logs, snoring loud enough to wake the dead, closing your mouth or pinching your nose or putting pillows over your face to kill the sound, you have the first sign that you might have sleep apnea. Of course, when you’re awake your airway is open, so that you don’t exhibit the symptoms(though there are people who’ve gotten so fat that because of their need for supplemental oxygen and a sort of narcolepsy where they tend to doze off a lot that they have a need for a cpap treatment round the clock, but again getting ahead of myself). Another sign that you might have sleep apnea is if you’re constantly tired, particularly even when you wake up in the morning. Of course, it might just be that you didn’t get enough sleep, but generally, if you don’t recall the last time that you woke up from a sleep really refreshed and ready to go(even if you slept in and got more sleep than usual), it’s pretty likely that sleep apnea is the culprit.

Now, our bodies and minds are pretty adaptable to all sorts of difficulties, and dealing with sleep apnea is another thing we seem to deal with. Because our bodies tend to doze off all the time when we are totally sleep deprived, our body will try any trick to get some sleep and recover. But, we’re smarter yet, and discover that if we eat food, that tends to keep us awake. Why, I’m not really that sure about the chemistry or biology of it, but suffice it to say, it works. Again, generalizing, many sleap apneacs, like me, tended to eat a lot at night, and particularly, later at night to keep ourselves awake. While in the short term this tends to keep you up, it has the not unexpected effect of making us fatter, since we’re eating to keep us awake and not to meet some hunger or other nutritional need. And, the fatter we are, the more likely that some of that new weight will find its way into the tissues of the throat and airway and make the apnea more severe and thus harder for our bodies to get some decent rest. For me, I discovered my apnea by the time my body was well over 350 pounds, probably having gained almost a 100 pounds over a ten year period as the apnea kicked in at some point and got progressively worse.

What are some of the other hallmarks of undiagnosed sleep apnea? Falling asleep at inappropriate times. As my sleep doctor said to me at one visit when I mentioned that I would occasionally doze off at a boring meeting, people with sleep apnea fall asleep at boring meetings, well rested folks without untreated sleep apnea stay awake and are bored at boring meetings. Now this sounds kind of simplistic, but it is absolutely true. Unfortunately, as bored as I get I’m consigned to staying awake during boring meetings(perhaps Dante’s 4th circle of hell?).Another, more serious complication of having sleep apnea and dozing off when sitting is if you drive a car. No matter how hard you fight to stay awake your body will often fight you and try and grab a few seconds or minutes of sleep whenever it can. A 5 second nap at a boring office meeting is embarrassing. A 5 second nap while you’re travelling 60 miles an hour is 500 feet of travel you slept through while controlling a two ton missile. Enuf said. Many folks who drive at night with sleep apnea dose up with lots of caffeine or other stimulants to keep them awake and ready to respond, but even that doesn’t generally do the trick. Driving with sleep apnea is dangerous to you, those who you love and care for riding with you and anyone else who might have the misfortune to be on the road at the same time as you. Okay, you’ve got the point and further jumping up and down and screaming won’t make the point any further.

Sleep apnea has other negative effects on us as you’d imagine. For example, how good for our heart and lungs and other organs do you think it is to have adrenaline pumped into the system once a minute when we’re trying to rest and sleep. Not good at all. In fact, sleep apnea, if untreated, can lead to heart problems, high blood pressure, diabetes, asthma and a variety of other conditions and diseases resulting from your body being stressed and tired and essentially running on empty. If you’ve ever pulled an all nighter or two in college or at some other time to get some projects done, you know that your body tolerates it moderately well at first, but at some point your body kicks back and you feel totally crappy, short of temper, physically lousy and very poorly able to deal with the world or complex problems.

So, you say, this sounds pretty lousy and not something I want to deal with. Fine, but life doesn’t give some of us that option. If you got dealt an airway that isn’t hugely wide and some tissues in your airway which make the opening a bit slender you’re likely to have to deal with this issue at some point in your life. If you’re fatter, you tend to enhance your chance to have the problem sooner. If you get older(with the alternative clearly inferior), you tend to enhance your chance to have the problem. If you sleep on your back you tend to enhance the likelihood that the problem will manifest itself. Of course, if you start to have the problem and get fatter and/or older it merely exacerbates the problem.

So, what to do. Well, surprisingly, sleep apnea is not a condition which can be cured. That’s the bad news. There’s no magic pill, surgery or device which cures you. But, there is good news. With a CPAP or BiPAP machine you can completely treat the condition so that it doesn’t trouble you. What’s the difference between a cure and a treatment? Well, with a cure you are done and the problem has gone away. With a treatment, you need to continue to pursue the treatment to keep the symptoms of the condition from occurring. So, if with the use of a CPAP machine you get a wonderful, restful, uninterrupted night of sleep, if you go a night without the machine, you’ll still get a lousy night of sleep. Of course, worse than just having a lousy night of sleep, your body won’t be so exhausted from months of no rest that it won’t know how lousy a night of sleep it’s getting. You’ll wake up the next morning bemoaning how you were up all last night(which in fact will be essentially true because your body won’t fall right back to sleep).

So, what’s the treatment regime for most people? A CPAP machine, which means a Continuous Positive Airway Pressure machine. This is a fancy way of saying that the machine blows air into your lungs at a constant pressure to keep your airway open so that when your diaphragm tries to suck air in to the lungs the airway allows the air to go in and then to come back out. The best analogy I’ve heard for the way in which sleep apnea and CPAP machines work is with a little round rubber balloon of the type we’ve all played with as kids and blown up as adults(or made into water balloons). When the balloon is uninflated it just sits there, with the big bulb not so big and the narrow walls of the neck of the balloon collapsed on each other so that there is no pathway through the neck of the balloon for air. However, if you apply a puff of air to the open end of the balloon, this can be enough to open the neck of the balloon and expand the balloon to its full, uninflated size. If you keep gently puffing on the balloon, not so much as to make it expand, but enough to keep that little neck region open, that’s what a CPAP machine does. The Continuous Positive Airway Pressure is the machine puffing air into your airway sufficient to keep the airway open so that when your diaphragm moves to suck air down into your lungs or force air out of the lungs, the airway is clear and air moves in the intended direction. The purpose of the CPAP is not to push air into you or prevent air from coming out, though many people are concerned that this will be the case. Generally, after a brief period of adjustment one gets used to the constant pressure and it doesn’t affect your ability to breathe in or out with the machine on. For people who require very substantial pressures which make breathing out hard(or who can’t get used to the pressure of exhaling), a BiPAP machine is prescribed. This machine has a lower pressure when you’re exhaling then when you’re inhaling(and more complicated approaches to sensing when this is happening).

The hardware that one uses is a xPAP machine(generic name for CPAP, BiPAP and AutoPAP(more later) machines), a mask or nasal pillows to cover at least the nostrils of the user when they’re sleeping, a hose connecting the machine to the mask and perhaps a humidifier. Some people also get supplemental oxygen along with the air, though that’s not generally an apnea problem, but as a result of other breathing needs. There are a wide variety of masks and nasal pillows that can be used and this is clearly a YMMV situation. The masks are generally nose masks which cover the nose and are held in place by a headgear which includes straps which go around the back of the head(top and bottom), although a full face mask is available for people who can’t help breathing through their mouths when asleep. They come in a wide variety of configurations and materials(though most have a soft, pliable plastic interface with your face so there is a good comfortable seal) and sizes. Some are designed for people who move around at night, others for those who sleep on their sizes. There have even been some developed recently for people who insist on sleeping on their stomachs. The nasal pillows are essentially two projections that rest up against the insides of your nostrils and are held in place by similar headgear. The nasal pillows are generally smaller and don’t cover as much of your face, though they do rest against your nostrils. Some prefer each of the styles and some hate them all. I use an Activa mask from Resmed which is supposed to provide a better fit if you move from your back to your sides, which I do, when sleeping.

I’ve been using a CPAP machine for more than 11 years and can honestly say that its given me back my life. Prior to getting the machine I always found my brain somewhat fuzzy and unable to exercise the higher level creative thinking that my job requires. However as soon as I started using the CPAP, the clarity of thinking returned almost immediately.

Over the years I’ve had a number of machines. The last two have been what are called APAP machines or Auto PAP machines because you set a range of pressures and the machine senses when there is a problem(through sound sensing) which requires increased pressure to keep the airway open. Generally, when in light sleep you require some pressure, but when you go to a deeper sleep or REM sleep your body is more deeply relaxed and additional pressure may be indicated. This sort of machine lets you set your base pressure lower and allow the machine to compensate for the problem by increasing your pressure during the night. I find that more than 90% of the time my machine operates at its minimum pressure setting with only occasional needs for more pressure. Most people just have their machines set to a level and tolerate a very limited number of apnea events without a problem. I’m too picky for this. Also, I acquired the software that lets me download the data my machine keeps about how long I’ve used the machine each night, the pressures that I had and even info about potential apnea events(though in some cases it is really just a matter of a mask leak which simulates for the machine what it thinks is apnea).

Well, I think that’s enough for now, and I hope that those of you who’ve labored through this find it somewhat useful. If you would like to know more or want some links to more detailed info, let me know.