Things That Come Afterwards

The bit at the start is controlled. Mostly. The bit at the end is more at the mercy of other things. Dr Andrew Weatherall has a practical review on emergence delirium. 

In showbusiness there is apparently a saying that you should never work with animals or children. I guess the theory is that both kids and animals inject too much chaos into your creative enterprise. Or at the very least they inject chaos without pretending there’s some deep and noble ‘method’ to what they do. They’re apparently just a bit too unpredictable without enough reason.

This has always struck me as a pretty unfair reflection on kids. For my money kids are mostly ruthlessly logical and straight forward. They just start from a different place with different fixed beliefs.

Besides, those showbiz types don’t know what crazy is. I’ve seen crazy. I’ve seen kids wake up.


Emerging Problems

Emergence delirium is not a small thing. It can be downright dangerous for the kids. It can mess with pain relief or even their surgery. It can be pretty distressing for them and everyone around them, related or not. It increases the work of those in recovery.

It is pretty much the pits all around.

It’s also common. When you read around you’ll find estimates of the incidence being somewhere between 2 and 80%. Precision, huh?

That might hint at issues either with the definition or of the management around the parts where you hit the 80% mark. Even if it’s 2% though that’s 1 in 50 kids which is more than enough to be taken seriously.


What does it look like?

In the manner of a high school debater trying to fill the many interminable minutes of a verbal battle, let’s start with a definition. Back when Sikich and Lerman were working on a scale for this vexatious beastie, they opened by quoting a description of “a mental disturbance during the recovery from general anaesthesia consisting of hallucinations, delusions and confusion manifested by moaning, restlessness, involuntary physical activity, and thrashing about in bed.”

That motor agitation is a key part. It’s not just that they seem disconnected from the world they’re supposed to rejoin.  I’ve had parents describe the situation as “I’m looking at them, and they’re looking at me, but my kid isn’t really there. They’re somewhere else and that place isn’t good.” That’s a pretty fair summary.

And who do you see it in? Well it’s common, so sort of everyone. It is a little more common in preschool kids and apparently a little more common in boys than girls. There’s a bit to suggest that the newer agents like sevoflurane and desflurane are more associated with delirium than the ones with a longer service record like isoflurane and halothane. There also seems to be a bit of link with ENT surgery, which probably wouldn’t be a surprise to anyone who seen the full fury of a kid waking up delirious after they’ve had their tonsils out.

Oh, and the kid with the white knuckles from clenching little hands into fists because they’re so freaked out? Yes, they are more likely to wake up with the appearance of someone negotiating unsuccessfully with demons from the nether world.

The other commonly cited component is early onset. The thing is it may classically be early but kids can do it up to 45 minutes after the end of the anaesthetic. And depth of anaesthesia doesn’t seem to have much impact on whether or not it develops, at least when guided by BIS.

So it’s a thing that happens a lot, that looks and is distressing, that can mess with both the surgery and your clever pain relief plan. It is one tricky customer all around.

Enough paying it respect though. What can we actually do?


A Stitch in Delirious Time Saves Quite a Few Stitches, Maybe Even Nine

If you hadn’t already thought this before reading I sort of hope you would be thinking “maybe this is a bad thing and maybe we should just make it not happen”. This is definitely a case for prevention being the aim.

Of course we have many drugs which we should discuss because this is anaesthesia and anaesthesia is really about drugs, right?

Well, just for that lets start with the not drugs bit.

Prevention Steps Before Chemical Help

Given that preoperative anxiety seems to be an issue it shouldn’t be that surprising that there’s a role for things other than drugs here. It might not be that a focus on reducing preoperative patient and caregiver anxiety removes the risk entirely but in at least one study a strong approach involving anxiety reduction, distraction, video preparation avoiding excessive reassurance and coaching showed benefits in both preoperative anxiety and delirium afterwards. In that case it even beat out preoperative premedication. It’s like they drugged kids with their words.

Other strategies that have been shown to help reduce anxiety include a quiet induction with less stimulus, music therapy, distraction, clown doctors (honestly this seems implausible in a bunch of settings because clowns can be a bit freaky, but there you go), video preparation and just informing parents well.

Perhaps the wide range of options here just tells us that being adaptable so you can get kids and parents through that phase with less anxiety in a way that suits them should be a key goal on every anaesthetic. If you don’t think about this pretty much every time, how do you expect to turn it on for the one time?

The Drugs That Work

Actually there are quite a few and it’s worth checking out the references mentioned at the end for a bit more reading. The short version is this:

  • Propofol seems to work given at the end (doses reported are mostly 1-2 mg/kg) or when infused intraoperatively.
  • α2 agonists seem to work, though patients will snooze onwards for a bit longer, particularly with clonidine. Clonidine doses around 1 microgram/kg get written up while for dexmedetomidine you can find reports of loading doses, infusions and one off doses. As little as a single dose of 0.3 micrograms/kg has been written up, but again with the lower rate of delirium comes a higher rate of sedation (including when compared to propofol). It may be a little more effective than propofol though.
  • Fentanyl at doses of 1 microgram/kg seems to help a bit (though with a bit more nausea and vomiting than propofol as a reference). It seems this is more than just an analgesic effect.
  • Ketamine works too (infusion or single dose) though nausea and vomiting is again higher than some other agents.
  • There are some other novel options like intravenous magnesium and gabapentin. On my reading it seems like the results are so mind blowing that you’d ditch the other options mentioned above though. There’s also some work suggesting dexamethasone might have a role to play (though maybe you should just enjoy the side benefit while using it as an anti-emetic).

It’s worth noting that midazolam, although good for premedication doesn’t seem to be that effective in preventing emergence delirium, at least in this meta-analysis.

Cracking Down

What if you end up with the kid in recovery rolling their eyes not in the “I’m just too cool for your slowly decaying reality old person” way? The first step should probably be to make certain it’s delirium and not something else, particularly pain. If in doubt, give analgesia some strong consideration.

Peacock Mantis Shrimp Kyle Williams

The eyes might not be quite as crazy as the Peacock Mantis Shrimp but pretty close. Pretty close.

If it’s not too severe then finding a person the kid actually knows to provide reassurance is probably a start. If your patient is at risk of causing injury to themselves or others it probably makes more sense to reach for some of the same things that work above – propofol, fentanyl (in a way said to be independent of analgesia) and α2 agonists again. Interestingly there’s at least one article describing the use of dexmedetomidine as a rapid bolus of 0.5 micrograms/kg over 2-3 seconds in this context without the patients being compromised.

At the same time it’s hopefully a reflex to make sure the environment is as safe as possible. Add pillows and padding, make sure the sides of the bed are up and decrease the chance of your kid getting tangled.

Approaches That Work

There are a lot of things to put together there and as a result most of us have seen a variety of approaches that work well for the clinician who employs them. So here’s the collection of practical things I do when trying to prevent or treat emergence delirium (particularly relevant to the higher risk groups), but it’s by no means a definitive list (and it’d be great to hear things that work for other people in their setting):

  1. Preparation of patient and family

Prevention is the goal here so management of emergence delirium really starts with the initial history, examination and information chat. This is the point where you hope to get the chance to get both the kid and any accompanying adults onside and a bit more relaxed. In the patient with a known history of being agitated after or very anxious prior the ideal world would let you get them through one of those preparation programs. For a lot of places that’s probably an unrealistic option.

  1. Consider premedication

I’ve worked with some clinicians who tend to use anxiolytic premedication with almost every kid and others who very rarely call on the drugs. I lean towards being selective but if the situation on assessment, chatting with carers or review of notes suggests it might be better, I tend to make sure it’s a dose of premedication that will work (meaning it is not at the lower end of the dose range) and discuss the fact that the wake up phase might be a little more leisurely.

  1. Optimise the induction

Low stress induction is obviously the aim for every kid, but I didn’t want to miss it as I went past. The path to making it low stress depends a lot on what works for that kid and that anaesthetist but at the very least it helps if the induction environment is quiet.

  1. Choice of agents

For most cases I tend not to use the shorter acting agents like sevoflurane and desflurane for maintenance. I’d lean towards isoflurane if using volatiles and I use a reasonable amount of TIVA with propofol. Certainly if they’ve had a bad experience previously I’d probably be reaching for the calm-looking milk.

  1. The other stuff

It’s also pretty vital to make sure there aren’t other stimuli that will either cloud the picture or make it worse. Excellent analgesia is a must.

  1. The end

Towards the end of the case most often I’d give propofol as a pre-emptive effort to hold back the emergence monkeys. In longer cases if I’m trying to get the volatile down I’ll practically convert to propofol TIVA.

  1. Giving yourself the best chance

Occasionally you come across a kid at a distinct disadvantage when it comes to making sense of things as they wake up. Kids who have challenges with sight, hearing or any other means of communication may find it even tougher. So in addition to making sure the pre-op communication is good, it might be worth making sure other things are taken care of – hearing aids in, visual prompts that might help, comfort items available and carers sooner rather than later.

  1. Stepping in to treat

Sometimes despite all efforts the delirium still pops up. In that case, it’s propofol again to provide a bit of a reset, and the dose required would usually be not much more than 0.5-1 mg/kg, though every now and then you might find you need to repeat. Obviously at any time of deploying propofol and heading back to sleep I’d pause and make sure everything else is stable after any dosing. No further movement or transport of the patient unless A, B and C are all in good order.

  1. The briefing

If there’s any worry about delirium the first people I’ll mention it to is those excellent recovery nurses who’ll bear the greatest burden of dealing with it. Then of course it’s any carers that are around. It gets a mention beforehand and then a mention again afterwards so it’s not a complete shock if it turns up. After all, you may end up asking them to help manage it so it’s good to give them a chance to prepare.


So there it is. Never work with animals and children they say. Well we don’t really have that choice, but we can apply some method to the madness.



You might note that this post is written with reference to the fairly standard kid and emergence agitation. Kids on the autistic spectrum might be at increased risk but there’s a post specifically with thoughts around autism right about here.

I found the image of the Peacock Mantis Shrimp in the Creative Commons area of flickr an it’s unchanged here from the version posted by Kyle Williams.

Following are a bunch of things you might like to read because going to the source literature is always rewarding:

Dahmani S, Delivet H, Hilly J. Emergence delirium in children: an updateCurr Opin Anaesthesiology. 2014;27:309-15. 

Dahmani S, Stany I, Brasher C, et al. Pharmacological prevention of sevoflurane- and desflurane-related emergence agitation in children: a meta-analysis of published studies. Br J Anaesth 2010;104:216-23.

Sikich N, Lerman J. Development and Psychometric Evaluation of the Pediatric Anesthesia Emergence Delirium Scale. Anesthesiology. 2004;100:1138-45.

Hilly J, Hörlin A-L, Kinderf J, et al. Preoperative preparation workshop reduces postoperative maladaptive behavior in children. Pediatr Anesth. 2015;24:990-8.

Frederick HJ, Wofford K, de Lisle Dear G, Schulman SR. A Randomized Controlled Trial to Determine the Effect of Depth of Anesthesia  on Emergence Agitation in Children. Anesth Analg 2016;122:1141-6. 

Makkar, JK, Bhatia N, Bala I, et al. A comparison of single dose dexmedetomidine with propofol for the prevention of emergence delirium after desflurane anaesthesia in children. Anaesthesia. 2016;71:50-57. 

Hauber JA, Davis PJ, Bendel LP, et al. Dexmedetomidine as a Rapid Bolus for Treatment or Prophylactic Prevention of Emergence Agitation in Anesthetized Children. Anesth Analg. 2014;121:1308-15.

Did you scroll this far? Good on you. Did you also note that there were a lot of easy jokes about working with animals and surgeons that were resisted? Just wanted it acknowledged.

4 responses to “Things That Come Afterwards

  1. Pingback: Things That Come Afterwards — Songs or Stories | Prehospital and Retrieval Medicine - THE PHARM dedicated to the memory of Dr John Hinds·

  2. Thanks for an interesting insight from the anesthetist point of view. My son had post-op delirium after a surgery at age 2 and it was really distressing – very similar to a child experiencing a night terror. He had to have ENT surgery at 5 and after talking through his history with the amazing anesthetist he had the smoothest ride!
    You guys do amazing work.


  3. Thanks for taking the time to read. While that better experience might partly be that little bit of extra age, it’s great to hear it worked out so well that next time.

    And that’s nice (but mostly we get given the chance to do cool work).


  4. Thanks for the great round up. I do a fair number of ENT lists filled with kids for T’s and A’s. I have been very impressed with the decrease in delirium that I have encountered since I moved from Sevoflurane to a propofol TIVA. I can think of instance in the last year.

    It is particularly striking when I compare it to the one day hospital where I often revert to volatiles as there aren’t enough syringe drivers. I do find in these instances that ketamine does the trick but often more of a cure than a prevention. I will have to try the dose of propofol at the end of the case. This is obviously just my experience and not exactly hard evidence ☺️

    Lastly, you mentioned a familiar and friendly environment. I always try to have a favorite bear, blankie or dummy in the recovery room. I think it is comforting.

    Again, as an aspiring paediatric anaesthetist, I really appreciate your blog! Thanks for all the effort that goes into it!


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