Sleep that isn’t quite sleep – or is it?

If it was up to me it would be all about sleep. Not so much getting large amounts of luxurious, holiday-advert sleep. I have no expertise in that. The drug-induced kind that also permits operations, that lets surgical types do their “nothing heals like steel” routine.

If you’ve missed it when I’ve mentioned it other places, I think anaesthesia is a little bit amazing. Shrouded in a little bit of mystery, initially peddled (well in the version from the west) by a dentist with hopes for a medical showman’s way to fame and wealth and revolutionary to our understanding of what constitutes suffering. There’s not much I can’t turn into an example of how great anaesthesia can be. Well, numbats. I can’t find a direct causal link to numbats.

Pretty great animal that brings its own leaves but it is possible anaesthesia would improve it.

Pretty great animal that brings its own leaves but it is possible anaesthesia would improve it.

Things Anaesthesia Isn’t

One thing that most people agree on is that anaesthesia isn’t sleep. It’s distinctly different, right? Well there’s a really excellent thing written by Jessa Gamble here examining one element of this – can anaesthesia satisfy the need for sleep?

Starting with testimony around the Michael Jackson case where a particular agent, propofol, was much discussed there’s a series of examples indicating that maybe general anaesthesia can be as regenerative as a good night’s sleep. So maybe you should all back off propofol, huh? (Poor old propofol – first it has its milky innocence smeared by an association with sexual hallucinations and then it ends up linked to a not-at-all trained cardiologist acting as a sleep consultant in an apparently pretty bizarre world.)

So if those pieces of evidence which provide the background links in that piece first mentioned are all about the restorative value of general anaesthesia, why aren’t there more informercials offering sweet, sweet drugs to dream years of fatigue away?

Subtle Distinctions

It’s just possible that a phenomenon we’ve spent more than a century struggling to understand might also have different effects on sleep given a different start point. It’s also true that anaesthesia generally isn’t something we’re offering in isolation and those other bits might matter too.

The article from The Last Word on Nothing is examining a specific question – can anaesthesia restore sleep debt? It covers some literature, a lot of it from animal work, where the subject receiving the anaesthetic starts from a point of sleep deprivation (and remember the starting point for that article was a particular case where propofol was being used for someone who hadn’t been sleeping). The suggestion is that giving an anaesthetic in this setting of sleep deprivation is effective at getting things back to an even keel.

I’m not sure that this also applies to the patient who turns up without sleep deprivation. Over the few days after anaesthesia in this setting, does the individual get the benefits of natural sleep or does sleep disturbance result? It might be their understanding around this clinical situation that led the experts mentioned to talk about anaesthesia as ineffective for those wanting slumber to make things more pleasant.

The Days After

Clinicians’ perspective on sleep disturbance after anaesthesia is related to research after surgery. In this setting sleep structure is altered. After anaesthesia for surgery, rapid eye movement (REM) sleep is generally lacking for a few nights, building a deficit specifically in this component of sleep. A few nights later, REM sleep suddenly returns in greater amounts to repay this debt. During this time the excess REM sleep can be associated with breathing disturbances, particularly in those who also have obstructive sleep apnoea.

This sort of sleep disturbance goes across age groups and different agents. 4-6 month olds took up to 10 days to return to normal sleep patterns after surgery for mouth conditions. This was in a comparison between different regimes to achieve the happy surgical snooze.

The agent for the anaesthesia can also make a difference. Propofol in the trials where we’re not talking about humans seems pretty even-handed with REM sleep. For other agents duration seems to matter. There’s a lot of things chipping in to the picture though. I haven’t even got into the bit where the opioids we use for pain relief also mess with sleep. Everything interacts. Why can’t sleep just be sleep?

Drugs for the Subconscious

The one thing that is easy to accept is that it is those drugs that hit the brain that mess you up. Oh, except for this one thing.

When you provide comfort for surgery and avoid general anaesthesia and opioids, you still get messed up sleep. In this one, they gave a spinal anaesthetic for lower limb surgery (where local anaesthetic introduced to the fluid around the spinal cord blocks the sensation that anything is happening) and then avoided all opioids for days afterwards. Sleep study in the days after still showed major distortion of the sleep architecture. Pretty similar for this study. And in this one for gynaecology surgery.

This might be because it’s also known that surgery itself can cause sleep disturbance and bigger surgery leads to more sleep derangement than smaller operations. I guess everything about surgery messes with sleep. I didn’t even get to the machines that go bing on the ward.

Which leaves us …

Still searching for understanding. Anaesthesia, which we’re still trying to understand, is not entirely like sleep. Except for when it’s very much like recovery sleep.

Of course there’s the other times when it entirely messes with your sleep. Not forgetting those sleep affects when having “not general anaesthesia”. Or the disruption caused by that surgery thing you were trying to avoid putting up with experiencing by having a “sleep” with the anaesthetic.

I hope that clears it up.

Probably the best response.

Probably the best response to all of this







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