Balanced Sedation in the ED. St.Emlyn’s
So I said………..
…., because I was trying to be a bit cheeky.
There is a serious point here though. I don’t know the exact motivation for asking the question but there is still a fair bit of scepticism out there about whether ED docs can do procedural sedation, but as it would be spectacularly dull to go over that ‘again’ and this is hardly the place to discuss it (anaesthetic common room seems to be the best place), it is fair to ask about whether we can do it better. Have you ever heard any of your colleagues (or maybe it’s you) say the following?
“I only ever use propofol for procedural sedation in the ED”
“Ketofol is fantastic, for everything”
“I never use Midazolam”
“Alfentanyl is loads better than Morphine’
Really? I have and when I do I secretly smile to myself and think that 1. You’re a bit of an idiot. 2. You are wrong at least some of the time 3. You are about to ‘get some learning‘……, and it may not be entirely cosy learning. I’m only joking of course as it really is a conversation that can get ED docs thinking about their practice in a way that can benefit patients.
So, what’s my problem here? Basically I have two issues. Firstly there is the one size fits all issue, and secondly (and perhaps more importantly) there is the issue of balance (which conveniently will help us deal with the first problem). Why don’t we start with a couple of examples and if you are in the ‘one size fits all camp’ give me your thoughts on the following cases.
Fracture dislocation 1
Fracture dislocation 2
So, if you were in the one size fits all camp…., are you still there? I hope not as although these patients have very similar injuries and very similar requirements for the ‘procedure’ the approach to how we facilitate this must surely be different. For starters let’s just break down what we are trying to achieve when we give procedural sedation. I think it is essentially four fold, and ‘sedation’ is just one part of what we require.
- Sedation - OK, let’s start with the obvious one. Sedation involves a reduction in the conscious level for the patient. This is beneficial in many ways as it allows a procedure to take place in a controlled manner with the patient’s passive or active cooperation.
- Analgesia - Most (if not all) the procedural sedation procedures we do in the ED involve pain so analgesia is clearly important.
- Amnesia - If you are going to do something unpleasant then perhaps there are benefits to not remembering it.
- Anxiolysis - If your patient is terrified, scared and anxious they will not be having a great time and may well be more sensitive to pain and distress. Surely it’s a good thing to do something about this?
- Muscle relaxation? - Did I say 4?? I think I did but I’m just going to put this 5th one in here as you might be thinking about it, and therefore you might be wrong……Some procedures (such as relocating shoulders) might well benefit from a degree of relaxation, but this is not the sort of muscle relaxation anaesthetists talk about when discussing balance. I would argue that in the ED ‘muscle relaxation’ is really just about sedation and analgesia rather than ‘true’ muscle relaxation, so although some people talk about muscle relaxation I don’t really buy it as a primary concern. Let’s not advocate microdosing muscle relaxants & if you suggest buscopan I will refer you to the regulator………(only joking, actually on second thoughts….).
In essence what I’m trying to say here is that the aim of procedural sedation is at least 4-fold (‘cos I still think muscle relaxation is actually about pain!). For patients the requirements for each of these elements will differ. In the earlier example we had two patients. One with extreme pain and anxiety, the other with moderately managed pain but pre-existing medical conditions.
Now it is entirely possible for us to use the same method in both patients. Let’s take an example of Propofol which seems to be very popular at the moment. We could give Propofol to the second chap, but we would have to give a TON of drug to achieve all the elements as although Propofol is a great sedative it ‘pants’ as an analgesic! Sure if we give enough of the magic milk to our patient their pain will be controlled (in that they won’t move to pain), but once that ankle is reduced and the pain is also relieved then they will quite possibly not breathe to pain either! As a learning opportunity that’s great as you get to practice your ventilation skills, and if you are really enthusiastic you might be able to run through a few ALS protocols as well, but as a clinical episode – pants. In the second patient we could use Midazolam, but really? Sedation requirements are minimal and do you really want to give a fairly long acting respiratory depressant to this man? I don’t and I don’t want you to do it in my resus room.
Arguably we could do either procedure (any procedure) with enough Fentanyl or morphine or midazolam or pretty much whatever you like really. The problem is that if you intend to use single agents then you may well end up giving a large dose of drug in order to get an adequate effect in all 4 of the areas that your patient needs.
The most important thing to remember is that sedation does not equal analgesia.
Getting a balance.
Balanced anaesthesia has been around for ages. Once we moved away from Ether as a sole agent (give enough and your patient will be asleep, relaxed and analgesed – oh and nearly dead) our anaesthetic chums have been mixing exquisite cocktails of drugs tailored to ever nuance and subtlety of the patients in front of them. A drop of this, a dash of that, sometimes it’s like watching Tom Cruise in Cocktail, and although such subtly is beyond our requirements we should be able to manage a pretty good G&T rather than serving warm beer all the time.
Balanced sedation is exactly the same principle. Evaluate your patient’s relative requirements for sedation, analgesia, anxiolysis & amnesia. How much of each do you need and which drugs shall we choose? Another example you ask? Why of course, let’s revisit our earlier patients and devise a strategy for each of them…
Fracture dislocation 1
What did we do? OK. This is a tricky one and if you said that you were just going to crack on and apologise for the pain later I think that’s OK. The foot needs to get back into position and you cannot wait until theatre is ready. Similarly if you wanted to phone a friend (our anaesthetists are great) then sure go right ahead, this is not straightforward, but what did we do?
We evaluated the patient and reviewed his meds, past medical hx and obs. As this was going to be a fairly quick procedure to reduce the fracture and to apply a POP we did not need a long acting agent. So
Analgesia – Yes, needed, but probably not huge amounts. Already has long acting opiate on board, and you don’t really want to give him lots of additional long acting opiate as pretty soon he will hopefully be in a a POP with less pain (and more reason to suffer resp depression effects of the opiate). He doeshave a requirement for some additional short acting increased analgesia though.
Sedation – minimal requirement has to be cardiovascularly stable
Anxiolysis – not a major problem
Amnesia – would be nice.
So our choice was Ketamine IV. Short acting with rapid onset and combined sedation and analgesic qualities. Good CVS stability and unlikely to cause respiratory problems (if anything likely to improve them). A total of 30mg Ketamine gave good sedation and excellent amnesia. Job done .
Fracture dislocation 2
This is a scenario where you can really put the principles of balanced sedation into action. Clearly this chap is in a lot of pain and you need to get on top of that first, and before you start with any sedation. If you just used propofol here you would be heading towards an OD. So with a fair bit of pain here and a painful procedure to come you want something that is going to work fairly quickly. Fentanyl is a good choice in this situation and so 100mcg of Fentanyl with some IV paracetamol and some 30mg IV Ketoralac (NSAID) will get you well on the way to good analgesia. Next up is arguably the anxiolysis and amnesia elements. A smidge (technically 1-2mg Midazolam in a fit healthy chap – beware the elderly) can go a long way to reducing the amount of stimulation this man is currently experiencing (might help with a bit of amnesia too). That then gives you time to ensure that you are ready to proceed to sedation with incremental doses of propofol until he is deep enough to facilitate manipulation and POP application.
At this point there will be at least one person saying….’Ketamine does all of this, that is the one agent I need, and to be honest it’s all 4 elements of sedation in one’. I would say yes…, but also no. Sure, if you are out in the sticks and you are limited in terms of time, facility, access, support, drugs I think you can make a reasonable argument that Ketamine is a pretty god agent. However, it’s not as elegant a solution to the one described above in achieving a balance. Having said that in our second patient if you were insistent on giving them just one agent then I would be happier if you used Ketamine than if you tried to kill them will with Propofol. Well maybe not kill them, but you really must understand the drug if you are going to use it, start with listening to the Propofol assassins.
Key to getting the balance right is to control pain first. There is no doubt that you will need to use less sedative agents if you control pain first. Then consider anxiolysis, often this is linked to pain so it may not be an issue once that is sorted, then, and only then is it worth embarking on sedation. Amnesia will hopefully follow as a natural consequence of the first three elements, but you may have to specifically address in rare cases.
If you are an anaesthetist who has reached this point with a systolic blood pressure of >200, chill. This is a blog post and not a textbook. The blog is here to raise the concept and to get docs to reflect on their practice. Relax and enjoy the discussion that I hope will follow.
In summary, if you are going to be good at procedural sedation you need to evaluate the needs of the patient assess their needs and then select the appropriate drugs to tailor their effects to what the patient requires.