Thursday, July 23, 2015

Sleep disordered breathing Catch-22: sleeping with post-operative nasal obstruction and an unreliable oral airway

How would a cetacean live with a blocked blowhole? 

The question was asked in a 1986 newspaper column ...

A--Whales and dolphins breathe only through their blowholes, nostrils found on the tops of their heads, according to Daniel Odell, a professor of marine biology at the University of Miami. In the unlikely event that their blowholes are blocked or damaged, the animals would probably suffocate, Odell [1] said.

These animals have no connection between the esophagus and the larnyx, and breathing through the mouth is therefore impossible. While underwater, these animals seal their blowholes by means of powerful muscles.

I suspect Dr Odell actually said the cetacean would definitely suffocate; their anatomy means they are truly obligate nose breathers.[2][3]

Humans, in general, are better off. We aren’t obligate nose (blowhole) breathers, we can breathe through our nose and our mouth… 

Oops. I should have said adults can do that. Human infants are almost obligate nose breathers [4], if their nose obstructs they are desperately unhappy and cannot readily sleep [4]. But it’s not just infants, many human adults have great difficulty switching from nasal airways to oral routes when sleeping: "Several patients also had a greatly increased number and severity of episodes of nocturnal oxygen desaturation”.

Humans, it turns out, have a bit of dolphin in them [3]. Our nasal airways are a primary breathing system, our oral airway is a backup system and a turbo-charger for high rates of gas exchange (as in running). If we breathe predominantly through our mouths we experience dental and soft tissue problems. Our nasal airways have a lot of complex adaptation to manage the challenge of large volume gas exchange including autonomic control systems that shift air flow from one nostril to another [5] and “turbinates” (soft tissue mounds) that direct air flow [6].

Actually, I think of us as having 2.5 airways. We have the turbo-charger/emergency oral airway and we have two nostrils that shift air flow between them and act somewhat independently. But that’s just me.

Which brings me to … me. Yes, this is one of those tediously long individual medical anecdote blog posts. It’s my anecdote of managing sleep for seven days with a post-operatively obstructed blowhole (nose) and an unreliable oral airway. The Catch-22 is that the same conditions that made the surgery necessary also mad the post-surgical experience very difficult.

I’m hoping that this writeup will be useful for people in similar circumstances, and for their caregivers. It’s long enough that it has sections - thee first is your informed consent. The second covers what most physicians won’t know. The rest are for the inexplicably persistent.

Informed Consent

I don’t see patients, but I’m a physician and science-based medicine is one of my interests. Over the past few decades I’ve seen several rediscoveries of what we used to call evidence-based medicine. That’s the earnest (and important) attempt to reduce the number of times we hurt people by fervently recommending something that’s totally wrong. All of these programs come up with a grading system for medical knowledge, something like ...

Grade A: Recommendation backed by really well done randomized clinical trials. That’s how we know that Magnesium Sulfate is great post-MI [7] and every woman over 50 should be on estrogen for osteoporosis …(*cough*). Right. Even the best double-blind randomized controlled trial research isn’t terribly reliable. How we deal with that is a topic for a different blog post [8].

Grade B: Research trials and animal models that funky statistical massaging of big data sets that give us a good reason to try something relatively harmless (we think) or to fund better research.

Grade C: Expert opinion from the great gurus. The kind of opinion that gave us thalidomide for morning sickness and bed rest for back pain. AHA “911” guidelines are Grade C. Yeah, Grade C is moving into coin flip territory.

This blog post is grade D. Medical anecdote — which is more useful than I was once taught but is still very unreliable. I’m a family physician who designs clinical software — I haven’t seen a patient in 16 years. On the other hand, I have discovered that diseases have a differently look when seem from the inside instead of the outside. So there’s that. In any case, you have been warned.

Managing post-operative dual airway obstruction

Some adults are semi-obligate nose breathers when sleeping. If we can’t breathe through our noses we don’t breathe. We may accomplish a partial failover to the backup oral airway system, or we might awaken with pleasant dreams of suffocation (or we might die, but we don’t understand that very well). If we continue sleeping we may drop our oxygen levels below what our brain demands.

So what can we do? The usual prescriptions for sleep disordered breathing are weight loss [11] and CPAP. Since diet and exercise rarely produce significant weight lost the first of these usually requires costly and complex surgery. Nasal CPAP, assuming insurance companies would pay for it [10] would be working against a closed passage — that’s not going to go well. On the other hand oral CPAP is nasty (oral airway is second best, doesn’t have filtering and warming, etc) and, of course, there’s the obligate nose breathing problem.

There are other options (see the long version), but my particular nose was obstructed by deviated cartilage/septum on the left and by hypertrophied turbinates on the right — the legacy of anatomy, age, and allergies. I’d failed two years of intensive allergy therapy including twice daily Neti Pot irrigation “with (*cough*) sterile water”. So I opted for nasal septum reconstruction (I think it’s more than septum really, but I’m not a surgeon) and resection of the right medial turbinate. My results at this moment are excellent, but we know long term results may be often unsatisfactory for older adults.

in any case this post isn’t actually about whether nasal airway surgery is a good idea, or has lasting benefit, or the overlap between sleep disturbance and sleep apnea. It’s about how one somewhat obligate nose breather managed to get enough sleep to live [20] be semi-functional during the post-operative week where the nasal airway is shut down by blocked stents [14]. I used 3 devices, all of my own devising [18]. There was no insurance coverage for any of them, so the cost would be prohibitive for most Americans.

Device 1: CMS-50E OLED Fingertip Pulse Oximeter $74

I wanted an alarm to sound if and when I desaturated. Amazon has many low quality oximeters for under $100 , but most don’t have an alarm. The “CMS-50E” has both an alarm and the theoretical ability to export data to a CSV file. 

In practice it alarmed several times, but some of them appeared to be false alarms related either to software glitches or low power. I think there were one or two genuine desaturation events. It did reassure Emily and I that most of the time I seemed not be desaturating (she could read it while I slept). I taped it to my finger to keep it in place. It comes with an unreadable paper direction set, but it’s not hard to find a readable PDF version on the web. That does not mean one can understand the directions! Hint — there’s only a single button with two modes - quick press and long press. Long press is how one selects menu items. You have to set alarm threshold (default isn’t bad) and enable the alarm. I compared readings to a non-alarming $45 oximeter I’d bought earlier, they had similar readings. With correct finger placement the readings had at least “face validity”.

There’s a $250 device that uses a similar cheap probe, and lacks an alarm, but can do some data export: Masimo iSpO2 Pulse Oximeter (30 Pin Connector with Large Sensor for Apple iOS Device)

IMG 0003

Device 2: Maintaining oral airway patency by supine neck extension $3

Anesthesiologists know about keeping flaky oral airways open (which is a sign of how unreliable an isolated oral airway is, it often fails in sedated patients). They manually advance the lower jaw (mandible) — but that’s hard to do on one’s sleep self. They also place a roll just beneath the upper thoracic vertebrae (upper shoulder blade) to extend the neck. Since I suspect one reason that i’m an obligate nose breather is that my oral airway sucks (pun) [17] I used this both with and without a very flat pillow. I was completely unable to follow my surgeon’s recommendation to sleep in a semi-seated position - my oral airway collapsed within seconds of early sleep.

The straps kept it rolled up and I threaded them through a T-shirt to help hold the roll in position. I think it helped in the first few days post-operatively.

IMG 0002

Device 3: An oral prosthesis to force mouth breathing $300-$400 or more

This was the key, though none of the four quite good physicians I saw knew of it. Or if they knew of it they weren’t able to connect that knowledge to my problem. I came up with the idea and proposed it to my dentist, who told me I’d reinvented something well known to dentists: Oral Appliance Therapy (see also weirdly good wikipedia article on mandibular advancement splint).

The particular splint he created for me fit onto my lower teeth (fairly comfortably, he’s a good dentist). It separated my molars and had a frontal ridge that was supposed to catch my upper front incisors and thereby stabilize the lower jaw. Perhaps because my lower jaw is so wimpy [17] it didn’t seem to do very much, but the separation of my molars was just barely enough to overcome my natural disposition to clamp my jaw firmly shut when sleeping and help open a small passageway that, with much noise and struggle, I would breathe through while sleeping [19].

There are many designs for these mandibular advancement splints, I suspect there’s not a lot of knowledge about which work best for which people. This particular design just barely worked for me in the post-operative period and it wasn’t enough to let me skip the surgery. For some people a mandibular splint might provide enough support for a not-completely-obstructed nose to avoid surgery altogether.

IMG 0001

These 3 devices, but especially the mandibular advancement splint, let me sleep post-operatively.

This would be a good place to stop reading, because the longer version goes into more details on the post-operative course and the clinical presentation...

Post-operative course

The surgical procedure took about an hour. Afterwords I was fine. My nose was obstructed of course, but I never had any significant post-operative discomfort. That surprised me, I suspect a well done cocaine nerve block.

At night things got nasty. I’d already experienced two years of intermittent suffocation, and the first two nights did not disappoint. Sleep felt like wrestling with a mountain lion. The second night was the worst because i was also sleep deprived, the 3rd and 4th were not a lot better but I did get a few hours of sleep, and by the 5th and 6th night I was doing significantly better. I think the improvement was partly diminished drainage, and early my body adapting to oral airway breathing. According to my wife the breathing sounds were quite impressive.

I found it useful to count to 40 breaths through my mouth while wearing the mandibular prosthesis, the drill seemed to help my troubled transition to an oral airway.

in addition to the devices mentioned above it helped to drink a lot of fluids and to get out of bed every 60-90 minutes and clear as much drainage as possible without, of course, blowing the nose (that’s apparently disastrous, and it felt like a very bad idea). If you were ever a 9 yo boy you probably remember how to maximize spitting distance. The same noisy and revolting technique applies. This especially worked after day 3 when the big dark clots come out.

I used the Neti pot nightly as my surgeon recommended. It didn’t contribute much as my nose was adamantly blocked, but I think it reduced discomfort related to dry clot.

For the first 4-5 days I wore a “mustache dressing” below the nose; contrary to the way it was taught me I found folding a 3” gauze into 3rd worked better than half. It has to be worn with minimal pressure or the tissue around the nose gets sore. I administered vaseline before applying.

Although I had no pain hydrocodone pain meds helped with sleep, probably because they make it easier to tolerate discomfort and perhaps because they make suffocation more tolerable.

Air conditioning was helpful too, I don’t know why. 

The stent removal didn’t bother me in the least. I was immediately able to breathe very well by nose. The Neti post was very helpful for the 3-4 days post stent removal, I used it twice a day. I resumed my antihistamine allergy spray post-stent removal but held off on steroid spray for one week. I then returned to a reduced version of my allergy regimen.

There were 7 medication related physician errors with my post-operative period. None of them caused any harm; they provided some light amusement for Emily (also a family physician) and I. Still, not great. 

The presentation 

I’m going to finish this up with a part that might be of interest to physicians. Namely, how did I first present with this problem. In brief, weirdly.

Two years ago, while on vacation in Florida after a long drive, I awoke at 2am sweating, breathing deeply and rapidly, with my heart pounding. It felt like a sleep terror, but I was about 40 years too old for those. My initial thoughts were about where best to leave my corpse given that the kids were in the room. I assumed i was having a major cardiac event, a new rhythm disorder (most likely), or a likely fatal pulmonary embolus (my mother had recurrent PE). On the bright side, maybe some degenerative neurologic disorder was manifesting as late onset panic attacks or a new variant of my adolescent sleep paralysis.

It never occurred to me that my airway had completely obstructed. In all my (admittedly dated) reading of sleep apnea I hadn’t read of such an acute onset. (Which may be another example of the fundamental problem with medical disease descriptions.)

Over a few minutes everything settled down. I felt fine, if somewhat anxious. Which didn’t fit most of my diagnoses, save perhaps the neuropsychiatric. At this time many physicians would have sent me to the ED, but for various reasons this would have been unusually difficult for my family. So I went back to bed. 

The problem recurred intermittently over the next few weeks, generally in a milder form. Then, on return home, it resolved. Until a couple of months later when it recurred and was associated with a sensation of “air hunger” (not getting enough air on deep breathing). So, after a bit of dithering, I went for my pulmonary embolus evaluation. Which, to the great surprise of both the ED doc and my wife and I, was negative. EKG was fine too, not to mention that I was into regular CrossFit by then. i’d be dead if I had a cardiac problem.

It was after ruling out the obvious causes, and having more regular recurrences, that I figured out that I was awakening due to asphyxiation. My nose, which had been gradually getting less functional over 30+ years, would completely obstruct, and I would fail to activate my backup oral airway. Which is, to be frank, quite weird. It took me a while to figure that out because I didn’t think it was possible. I suspect a non-physician would have made the diagnosis months before.

After we knew what was going on I did see an ENT and I attempted (but failed) to meet up with a sleep specialist [22]. I then embarked on my family doc's recommendation of Neti pots and maximal medical therapy — in part because of my research showing uncertain long term value of nasal surgery and in part because medical types don’t trust surgeons. I got to maximal medical therapy after an allergist visit, and when that failed I opted for surgery. It was during the two years of medical therapy that I came up with my approach to the post-operative period. 

- fn - (lots)

[1] Dr Odell joined SeaWorld in 2001. I assume he’s retired by now, but hope he’s doing well. The web gives us odd glances into people’s lives.

[2] So how do cetaceans produce sounds you ask? Well, that’s where things get weird and fascinating — too odd to put into a blog post. Cetaceans have sets of laryngeal air sacs that may, or may not, be analogous to our (useless?) paranasal sinuses. So one theory is they vocalize like a Scottish bagpipe (used as a comic illustration in that article). The best article I found was a fine post in a flaky sounding blog; turns out there’s a surprising amount of uncertainty. The article doesn’t explain why captive dolphins open their mouths when demonstrating sound production in air.

[3] The fact that an aquatic mammal can evolve to segregate oral and nasal airways does put an interesting spin on human obstructive sleep apnea. We are notoriously good swimmers for a land animal. Alternatively, we also are notoriously good at producing complex sounds, that ability might also have required some compromise of our airway systems. Natural selection would not produce a compromised airway system without a powerful adaptive advantage [4]...

[4] Are infant chimpanzees obligated nose breathers? It would be fascinating if they were not.

[5] Many people notice that one nostril or another is dominant at different times, including variations with head position. This isn’t a random thing, it’s a control system that, we assume, enables tissue rest and recovery.

[6] Years ago surgeons managed some kinds of nasal airway problems by removing the turbinates. This worked well at first, but then patients developed “Empty Nose Syndrome”. Which, of course, we don’t really understand. The neurophysiology of nasal breathing is complex. Incidentally, the nose is much bigger than you think.

[7] Nobody but me will remember the @1992 Mag Sulfate post-MI study that made it into the textbooks but then was reversed by an even bigger study. At that time I was a keen young physician teaching curmudgeonly old braindead docs to use “Grateful Med”, with slides (real slides, or transparencies, prepared using Symantec’s MORE 3.1). I used the then obligatory graph describing the volume of medical knowledge and bemoaning the backwardness of physicians who didn’t read the latest journals. 

That one small reversal shattered my faith. That was when I looked at 10 year old journals and saw how few of the “best” recommendations survived. I proposed, but never pursued, writing an article that tested the non-evidence-based idea that one should read medical journals. Thankfully others were more persistent than I and made a fine academic career of looking at the lifespan of grade A research results. I no longer see articles bemoaning physician failure to track the latest fads.

[8] Ok. The usual answer is meta-analysis. I think we need to look at predictive Bayesian models. So combinations of human clinical trials plus animal models plus biology … Yeah. Needs a separate blog post.

[9] Brains and hearts are the oxygen fiends. Presumably desaturation happens a lot more in Denver than in St Paul MN, but I haven’t seen much discussion of that.

[10] CPAP seems (do we have 15 year natural history studies?) to work well for sleep apnea and sleep disordered breathing - at least for people with working noses who can tolerate it. For reasons I don’t fully understand (expense of evaluation? expense of device/use?) insurance companies are reluctant to pay for it even as demand seems to be rising. So there’s now a big complex hassle around sleep disturbance evaluation, apnea diagnosis, and CPAP use. But this blog post isn’t about apnea ...

[11] FWIW if I got skinnier my wife would send me to an eating disorder program. 

[12] What messes up the septum? Mine was deviated in childhood. The usual explanation is trauma, but I also have a developmental anomaly of my chest wall. So I wonder more about a developmental growth disorder. The allergies are a lifelong nuisance. My surgeon claims that it’s common to see hypertrophy of turbinates on the unobstructed side — presumably due to some mix of missing feedback, increased work, allergies, etc.

[13] Yeah, nasty brain eating protozoan. I probably should have paid to install a filtration system at home and just take my chances when traveling, but I just used tap water.

[14] My surgeon didn’t use old style packing, but “stents” have to placed to stabilize the septum. In my case they were removed one week post-operatively. In theory they are designed to allow air flow, but in practice they always obstruct immediately and cannot be cleared. Material used to reduce bleeding likely contributes to obstruction.

[15] CSV export requires use of a flaky Windows app I’d want to run through a first class malware scanner. I didn’t bother trying to configure it on my Mac VM.

[16] All sold only for “exercise monitoring”, not for medical use. Almost all the reviews are for medical use.

[17] I have the classic small weak puny jaw of the pencil neck geek. I was amazed by the quality of wikipedia articles related to airway problems — maybe there’s a small-jawed-geek-airway-syndrome to be discovered? Something related to maternal testosterone levels perhaps ...

[18] None of these were invented by me of course! I mean that I thought of them in the two years of dreading post-operative asphyxiation. If I had thought to read wikipedia instead of medical articles I’d have learned about the oral prosthesis immediately, instead of having to reinvent it and find my dentist made them. None of the four quite good physicians (and one inexperienced sleep specialist PA [22]) involved in my care, including one family physician, two ENT physicians and one allergist had anything useful to contribute to this particular problem. I think it’s a problem that falls into the black holes between medical specialties, and particularly between medicine and dentistry. Which is appalling, but not surprising. I’d be no better save that I had to solve this problem. The medical literature sucks. Which is why, of course, I spent hours on this blog post.

[19] So why do I firmly clamp my jaw shut while sleeping? I don’t know. My theory is that I have an anatomicaly lousy oral airway, and that I learned to clamp my jaw shut at night to stabilize it and allow nasal breathing before my nasal airway failed. I needed to undo that reflex to get through the post-operative period.

[20] I thought we couldn’t go more than 4-5 days without psychosis or serious health issues. i just now learned that’s wrong — in 1965 Randy Gardner, a 17yo madman, went 11 days for a science fair project. He seems to have subsequently led a fairly quiet life. He had a cat in 2006. So maybe I could have dosed up on modafinil and made a run for 7 days.

[21] Neti pots are one of those weird devices that seem perfectly hideous and revolting on first use but become relatively familiar and appreciated. It’s worth pushing through the initial ickiness to be able to use them for colds and allergies in place of medications. Just watch for the brain eating amoeba [13].

[22] The sleep specialist evaluation was a classic 2015 American medical fiasco. I ended up seeing a brand new (inexperienced) PA who recognized I didn’t fit the obese-apnea pattern they saw 40 times a day and didn’t really know how to proceed given my nasal obstruction and the expectation that I’d have disrupted sleep rather than sleep apnea. The roots of this mess-up had to do with all of the protocols sleep specialists and insurance companies have put in place in their CPAP revenue battles, a recent corporate acquisition of the practice, a problematic transition from sleep center to home sleep studies, and a disruptive electronic health record transition. This was my only medical-bust of the evaluation.

See also

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