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On living with CPAP

Getting old sucks.

It's bad enough that things I grew up thinking of as futuristic and innovative (audio CDs, synthesisers, vegetarianism) are now seen as "retro"; it's bad enough that I now have more hair in my nose and ears than on my head; but it's worse that my body has started to let me down. Even sleep -- something we nearly all take for granted -- can eventually become a hazard. I remember on one occasion when I was about forty years old, on a mountain hike in the Pennines, wishing I was as fit as I had been in my thirties. I wondered then if one day I would lament the fact that I wasn't as fit as I had been when I was forty.

The answer turns out to be: yes, I do. But, worse, I now look back with nostalgia on how fit I was when I was fifty. The worst about all this, though, is that I know it's all downhill from here. As lamentable as my health is now, it's as good as it will ever be in this life.

Obstructive sleep apnoea (OSA) is a medical condition that mostly affects men (and occasionally women) from about age fifty. If you're thirty and already suffer from OSA, then you have my most profound sympathy: that really blows. But, frankly, it's not a chuckle-fest when you're getting on for sixty, either.

In OSA, the tissues of the soft palate relax when you fall asleep, and fall back to block your airways. It's the result of a stunningly bad design decision, but one that's no worse than the decision to have humans eat and breathe through the same orifice in the first place. Frankly, we weren't designed/evolved to be healthy past our fifties.

The unconscious brain is surprisingly stupid about some things so, when your air supply is cut off, your brain generally doesn't take much action until you've stopped breathing for tens of seconds. By this time you're really hungry for air, but you don't realize until you're jolted awake in a state of panic. Eventually, though, over months and years your conscious mind adapts to the repeated jolts by the simple expedient of ignoring them; this is when the condition becomes most dangerous, because constantly-interrupted sleep is extremely toxic to body and mind.

Most people with OSA come to the attention of a healthcare professional when they're so sleepy during the day that they can't function. A few are encouraged to seek help by their partners, because they snore like tractors. Just a few (like me) have no textbook symptoms at all, and the OSA is only detected by accident.

OSA has a long and scary list of adverse health effects, but most medical authorities don't even mention the symptoms that are nasty, but not health-threatening. My main symptom, for example, is dreaming that a huge fat man is sitting on my chest. Other people complain of relentless nocturnal bathroom visits, sore throat, headache, or loss of libido.

There's really only one effective treatment for OSA, unless you can shed about forty percent of your bodyweight. That's to use a machine to blow air into your lungs through a mask all night, every night. This is "continuous positive air pressure", or CPAP. It's "positive" pressure because in normal circumstances the air pressure in your lungs is reduced to lower than atmospheric when you inhale; with CPAP, your airway pressure is always greater than atmospheric. That is, your lungs are always partly inflated. This partial inflation of the lungs might, in some circumstances, be beneficial in its own right - but this is really only a side-effect on the pressure needed to keep your soft palate out of your airway.

Using CPAP means resigning yourself to having an obtrusive medical appliance in the room where you sleep, for the rest of your life. It requires you to wear a somewhat tight-fitting mask, attached to an air hose that restricts your movement. The mask will probably leak air from time to time, even if it's fastened tightly enough to leave a permanent impression in your scalp. What it does leak, it will wake you up, along with anybody else sleeping in the vicinity. If you're very lucky, the leaky mask will make farting noises, which is at least amusing, in a childish kind of way.

The very notion of having a permanent medical appliance in the bedroom is a scary one. I thought initially that if I covered the air hose with a fleece liner decorated with cartoon characters, it would make the bedroom look less like an intensive care unit. I was wrong -- it makes it look like a pediatric intensive care unit. The CPAP appliance is usually noisiest when the user is asleep; and that's fine, so long you sleep alone. Another person in the same bed might be asleep when the device really kicks off. But not for long.

If you have even slightly sensitive skin, the mask will irritate it. I've heard of people developing sores and blisters but, to be fair, the worst I've had is pimples. Pimples are bad enough, though, when combined with impressions of the mask straps all over your face for the first two hours of every morning.

Masks are usually full-face (obtrusive and uncomfortable), or nasal (uncomfortable outside allergy season, and then unusable). On most masks the part in contact with skin is made of silicone rubber which is at least easy to clean, even if it's uncomfortable. Many CPAP users fit their masks with fabric liners, which are more comfortable until they get damp with condensation (or worse), at which point you end up with a diaper rash on your face. One manufacturer makes a mask with a soft "memory foam" cushion which is more comfortable than silicone, but doesn't completely avoid the diaper rash. Unfortunately these mask cushions are expensive and short-lived, so really only practicable for the super-rich.

Many CPAP appliances humidify the air to make it more comfortable. If it's very cold in the bedroom, the warm, wet air will condense out in the mask and hose. It's particularly unpleasant if it mostly collects in the hose, because a sudden movement might cause the hose to discharge its entire load of freezing cold water into your mask. This is the notorious "rain out". CPAP users soon learn how to hang their hoses so that condensation runs back into the machine, rather than into the mask; but condensation in the mask itself is hard to deal with. A heated hose reduces these effects, but at the cost of increased weight and reduced flexibility.

Then there's all the maintenance. The mask will need regularly cleaning, the extent of which varies between designs. The humidifier will need to be refilled pretty much every day, cleaned every so often, and occasionally descaled. The machine will have an air filter than needs to be checked regularly, and sometimes cleaned or replaced. If you're recording data about treatment effectiveness -- and you should be -- the machine's data memory will need to be backed up periodically. Every so often the complete apparatus will need to be serviced. Between services it will need to be checked regularly for leaks, because a leaky hose or coupling will reduce treatment effectiveness.

Most CPAP appliances are self-adjusting to some extent. Back in the day, you'd have a laboratory study to work out the minimum air pressure that kept your airway open, and then be issued with a machine that generated exactly that pressure. These days, it's widely accepted that a user's pressure requirement will change over time, and it's better to rely on the machine to deliver the correct pressure. In many cases this works fine, although fully-automatic CPAP machines are much more expensive than fixed-pressure ones. In any event, you need to keep the pressure as low as it reasonably can be, while still relieving symptoms, because to high a pressure leads to the nightmare of aerophagia.

Aerophagia (literally "eating air") is what happens when you swallow when your oro-nasal passages are exposed to positive pressure. Every time you swallow, a small amount of air is introduced into your stomach, and that air has nowhere to go. Well, actually, it does have somewhere to go -- eventually. You can be sure of a measure of discomfort until it gets there, and then embarrassment when it does. Aerophagia is one of the most common causes of treatment failure -- you've got to be really dogged in your compliance with treatment, to put up with fifty litres of air in your abdomen all the time.

So how do OSA sufferers put up with all this? The answer, I think, is that many don't. In general, sleep specialists regard "compliance" as amounting to two hours of treatment per night. To be fair, if you can keep the mask on for two hours, you'll probably get two hours' sleep, which is two more than you would otherwise have had.

Learning to love (or at least tolerate) CPAP starts with learning to love the mask. You almost certainly won't have success with the first mask you try. Probably not the second, or third either. You'll probably need a bunch of masks, that you'll rotate on a nightly basis, so that you don't irritate the same part of your face every night. Masks are generally not particularly shape-conforming, nor are they available in a huge range of different sizes. A mask that fits well at some points will probably hurt (or leak) at others.

Then you'll need to adjust the CPAP appliance carefully whilst studying the treatment effectiveness over a long-ish period of time. Nobody but you is going to take this kind of trouble over your treatment -- certainly not your doctors. With the best will in the world, no doctor has enough time. The goal is (usually) to find the minimum pressure that will keep apnoea episodes to a minimum. "Zero" is probably not an achievable goal -- even people without OSA will experience some short periods of apnoea. In the UK, the usual threshold for treatment is an AHI score (number of apnoea or hypopnea episodes per hour) of 5.0 or more. But that amounts to being forcibly roused every twelve minutes on average. Does that sound like adequate sleep quality? I generally aim for an AHI of about 1.0, and don't worry overmuch if it slips above this level from time to time. I prefer to accept a slightly higher AHI (larger number of awakenings) than to have a belly-full of air and my eyeballs bulging out.

The other aspect of dealing with CPAP is to develop evening and morning routines that become second nature. There are so many things to do, to manage a CPAP set-up, that you can't be working out every day what they are -- not if you want to keep your sanity, anyway. Most machines have timers to warn the user when it's time to check or change the air filter, or replace the mask hose; but these are only a fraction of the chores you'll have to do. Since most of these chores have to be repeated daily, or at least every second day, they do eventually become second-nature.

I've heard it said -- and I'm inclined to believe -- that it's easiest to tolerate CPAP if you're highly symptomatic. If the treatment makes a huge difference to your overall quality of life, it's easier (I guess) to tolerate its quirks and annoyances. If you're essentially asymptomatic, as I am, you're faced with the choice between an unpleasant, obtrusive, inconvenient, life-long treatment, and the uncertainty of future poor health.

What a choice.

[ Last updated Tue 22 Feb 19:28:25 GMT 2022 ]