• 16 Mar 2021
  • 23 min 16
  • 16 Mar 2021
  • 23 min 16

David Liew talks to anaesthetist and pain medicine physician Gavin Pattullo about managing patients’ pain once they are discharged from hospital after surgery.  Read the full article in Australian Prescriber.


Welcome to the Australian Prescriber podcast. Australian Prescriber, Independent, peer-reviewed and free.

I'm David Liew, your host for this episode. Today I'm joined by Gavin Pattullo, who's the Director of Acute Pain Services at the Royal North Shore Hospital in Sydney. Gavin, welcome to the program.

Thank you for having me along, David.

Thank you for writing such an excellent article in Australian Prescriber on management of postsurgical pain in the community. Certainly it's a topical area, but why does this really matter? Why do we have to specifically focus on this particular issue in amongst all the opioid issues that we presented with?

Thank you, David. That's a good question. I think it's very pertinent for us to have a conversation, particularly for clinicians working outside of hospitals. And that really was the target of the paper. And I think it's important because a lot of changes have happened in the last few years. We've got obviously all of these regulatory authorities for warning us about the misuse of opioids and many of the strategies we've used in the past have kind of been taken off the table.

We're seeing an increase in enhanced recovery after surgery-type programs, which is where we're trying to get people up and out of hospital quickly. That means a lot of patients are coming out of hospital much earlier and they often have an expectation of functional improvements that can be very, very difficult for us to deliver. I think with all those things to consider, it's the free pertinent paper that we tried to address some of those issues.

I mean, it's really a time in the patient journey where there's a lot going on with pain. And at the same time, I get the sense that this is a point in the patient journey which can be quite critical in terms of how things go on in the future.


Great. Before we actually get into how you might approach this, what can go wrong at this point?

I think the major issue, which we didn't really go into too much in the paper. So I'm going to go a bit off script if that's okay, David. Is our understanding of what pain is. It's been a factor reiterated previously in journals that medical students get less training about pain than veterinary students. It's just assumed that as doctors, we understand pain. Pain is often been analogised to our perception of colour. What you David see as blue may be different to what I see as blue and the same kind of analogy can be used in pain. When I have a trainee on my round, we'll spend quite a bit of time actually covering that topic of what actually is pain. And the key point that we'll go through is to reiterate the line from the IASP, International Association for Study of Pain, just that first line is the key line, pain is an unpleasant, sensory and emotional experience.

There are three key words in there, unpleasant, then sensory and then emotional. When we talk about unpleasant, other words can be used such as bothersomeness, troublesome or can't cope. It has to be that specific issue that we're dealing with. And in sensory and emotional, what we're referring to is the human body's sensory systems. We have an ability to detect nociception, so noxious stimuli, and that is then integrated in the human body with the emotional component, which comes from our limbic system, that's quite a unique human experience. And that’s when you get the whole experience of pain. The IASP goes on to ensure that clinicians differentiate between pain and nociception, that they are two completely different entities. What often you'll have is a patient telling you how much nociception they're feeling, how much sensory inputs they're getting, when you are hoping to find out how much pain they're getting, or they might be trying to explain to you how much pain they're getting, where you're trying to get an idea of how much nociception they're getting.

That's one of the key issues we have clinically is for both the clinician and the patient to be very, very clear. What are you actually talking about? Is it how much stuff you're feeling, how much sensation you've got, or are you telling me how much you're bothered by this pain? And that's why we've moved away particularly from pain scores. When we do the pain round, we will very, very rarely ask for a pain score on you if we're doing research, but in clinical practice, the zero to 10 numerical rating scale has just too many flaws in it unless it's done correctly. We're talking more about, is this troubling you? Can you cope? Those sorts of questions are more our emphasis nowadays.

Hm, well, what does that really mean for ... What are the implications of that for the way we prescribe and the way we manage pain as a whole?

Good question. The emphasis we give to our trainees is first and foremost, let's try and deal with the nociception. Let's stop the signal, making its way up to the thalamus. In our hospital where it's a little bit different, we've got the option to use neural blockades so epidurals or peripheral nerve blocks, that's the most effective way to stop nociception. When that's not available, to clinics in the community, then the next most effective strategy is a use of the anti-inflammatory class of medications, the NSAIDs/COX-2s.

They are the most effective agents that we've got to stop nociception. And so we'll put a real emphasis on ensuring that nociception-blocking modalities are emphasised and optimised. And that's usually the most common thing that we see clinically in terms of medication, that the NSAID/COX-2 class has been not included. That's where we go into in some detail in the paper about the myriad relative contraindications that persist out there in terms of the use of the NSAIDs/COX-2s. And a lot of our strategy is educating about whether or not those are valid contraindications and really looking closer at those to make sure that this class of medication is optimised.

Mm. Do you think that we underutilise anti-inflammatories in practice in the postoperative space?

Yeah, I would definitely say yes. That is sort of the most common medication that I'm adding to a patient on their acute pain round is an NSAID/COX-2. I don't think sometimes it's not unreasonable for a clinician to withhold that because they’re concerned about whether or not the patient's going to need it, or it's going to get some adverse effect. How we particularly know that someone needs an NSAID or a COX-2, the sine qua non will be that they'll have movement pain. And that is the type of pain that responds most effectively in NSAID and COX-2s. Because there's, as we all know, they kind of work in the periphery that prevent that peripheral sensitisation, prevent the signal from ramping up and getting out of control.

If the patient can't move, can't breathe, can't cough, they're reporting all those sorts of what we call dynamic pain then that's a clear indication that they will need the NSAID/COX-2. If it's rest pain, which is not so common, it's unlikely that the NSAID/COX-2 will be effective for those. We'll often withhold that in that scenario, but if they're saying, yeah, I can't get out of bed, and all they've got is Panadol and an opioid, it will be quite clear that they need an NSAID/COX-2 added in that. You've just got to go through all the common contraindications.

I guess it's probably a relevant point to stop and think about what kind of things are going to influence the experience of pain. Obviously in the postsurgical period, it depends on what surgery we're dealing with, but there are also a whole lot of other factors, I guess.

Absolutely. We sort of touched on a little bit about the biological processes of what's going on in the neurological system. Undoubtedly, a large component and a lot of the emphasis these days is on the psychosocial component. Remember we talk about pain requiring a biopsychosocial management. The bio we're all very familiar with in medicine, we're taught all about the medicines that's about medications or interventions. We're all over that. The psychosocial thing is this kind of like grey box that no one really knows what that means. It's kind of like, oh, do we get a social worker in, it's this grey zone and we're not really taught it very well. But certainly the emphasis on that now is the psychosocial is very much to do with communication with the patients. With message framing, in terms of how you deliver your message. One other area, that's very exciting that we're moving a lot in is what's called a placebo-enhancing communication strategy, which is where we induce the endogenous coping system to provide analgesia for a patient. That can be done very successfully by our communication with our patients.

Such things is, you'd say to the patient, these are very, very helpful medications, they're very powerful medications. They're going to help you to cope with what you're feeling and most patients find them very, very helpful. Whenever you need to say that script to accompany any medication you're providing to a patient, we do know placebo is very, very powerful. What I'm talking about there is, there's two sort of sub categories of placebo. There's, we talk about placebo response, which is just progression to the mean that's, everybody just gets better with time. Well, not everybody, but most people do. And there's also placebo effect. And that's the effect you get due to expectations and conditioning, which is actually a biological process that you induce in the patient purely by expectation.

I've been to see a doctor, he seemed to know what they were doing. They were in a nice room and they provided me this new fancy medication, for example. And I'm used to that when you take a new fancy medication, you get better. That's all the conditioning and expectation. What we want to do is very much induce that as best as we can clinically. That's taking the psychosocial approach.

Hmm. All right. Well, let's start to talk a bit about opioids and I think that's the thing that we all realise has been a looming issue for a number of years now in Australia. What's your approach to trying to manage opioids in this postoperative space, especially in that dealing with postsurgical pain in that transition of care from a hospital setting to a community setting?

Certainly, I think the first is, that's why we, with our trainees, we really emphasise and understand what's going on with the patient, with their pain. Making sure that you've optimised your anti-nociceptive strategies. Opioids then really should be seen not as a frontline, but they’re kind of second or third line. They are in fact, if anything, like a rescue strategy. If your other things haven't worked, then you roll in your opioids.

Opioids are most effective at relieving the distress component of the pain. If the nociception that's coming in is too much for the patient to cope with, that's when opioids will work very well. They will have a little bit of a role in terms of mopping up excessive nociception that you haven't been able to deal with other medications, your NSAIDs/COX-2s, because there are some people that you just can't give it to for whatever reason. Someone who's got renal impairment is a nice example. Then you've no choice but to resort straight to the opioids.

But the key thing is to understand what that opioid can do and how it's working. That's predominantly removing the affective, distressing component of that patient's pain. It’s not going to be so effective at actually stopping the signal getting in, so they’re going to still feel stuff as we say, sensations, but as long as the patients understand the role of the opioid, I think that's really important as clinicians too, that we often think analgesics are all exactly the same, they're all interchangeable. But they're not, they all have very, very unique qualities in how they work. And that's the key with the use of an opioid is for patients to understand what its role is, it’s particularly to help them to cope, to relieve their distress.

And that's what we want to try and see, from when we provide it, when we initiate an opioid, is be very clear, well, this is how I want you to be using it. I don't want you to just be using it because you're feeling ... I mean, we come across it all the time. People are taking it because they feel their stitches. Well, that's not what opioids are, they won't stop you from feeling your stitches. You're still going to feel the stitches. If that feeling is too much for you to cope with, maybe we can look at some other strategies first, which is, again, message-framing and placebo-enhancing communication strategies to induce the endogenous coping systems.

Hmm. How do we approach this in practice? Obviously it is partially about identifying those high-risk groups, but how do you go about trying to assess a patient?

The first thing is really trying to work out is that distress that they've got going to respond to an opioid and then it's really essentially a trial of an opioid and we're going to trial a short-acting opioid or an immediate-release opioid and gauge the patient's response from that, bearing in mind that there's quite a variation in patient's dose requirements. And sometimes you may need to escalate the dose acutely. Someone who has 5 mg of oxycodone and says it doesn't work, well it may be because the pain doesn't respond to opioids or maybe you just haven't reached the effective dose for them. So sometimes it's a matter of judging whether or not that's the appropriate dose for them.

And dosing, we've made a mention about that, one of the common pitfalls we see clinically is this extrapolation that opioid dosing is based on weight, which is not the most valid determinant of opioid dosing, it’s actually age, with the peak being in the early 20s. And as you get older, your dose requirements reduce. That's important, because you'll often see someone who's in the obese category and someone says to you, oh, that patient needs more because they're 150 kilos. If anything, actually, they probably need less because they're more likely got either known or unknown diagnosis of destructive sleep apnoea. And they are very vulnerable to a ventilator-impairment effect of the opioids. You would be very careful about prescribing in the overweight group of patients.

That would be the overall approach we would take. Drug selection really depends on largely your experience, I suppose, but we're tending to roll in with pure opioid agonists, as we've mentioned, their coding is not really a favourite agent, just because you have such variable pharmacology that we're all aware of. Whereas if you're using a pure opioid agonist, you know for sure that the patient's receiving what you've prescribed them.

Okay. And I guess speaking about opioids, we've known about tramadol for a while. There's been a lot of talk about tapentadol, and I think it's probably a bit of a leading question, but are these a panacea for all the issues that we've got or is it a little bit more complicated than that?

Yep. Probably leading question. Our own experiences at our hospital is that tapentadol has led to a very, very rapid escalation in the prescribing of it because it's seen as, and rightly so it is a very, very safe medication. There's been something like four deaths in the world since it came out, it's extremely safe, but that then does not give us a carte blanche licence to just give it to everybody, which unfortunately seems to be what is happening. What the concern is with that approach is that you are again, instilling in the patient a belief that they've got a drug-deficiency state, that all they need is take more medications that will start on tapentadol. And then that will then be pressure that they will apply when their pain isn't relieved on a clinician to get something stronger.

That's the main concern that we have about these newer medications. We should still see them like any other analgesic. You have to determine whether it's appropriate for that patient before prescribing it. And ensure that if they're not getting the response that you expect that they have a cessation of that medication.

I guess that's really what happened at the beginning, if we're to kind of go back and thinking about oxycodone --

Yeah. I mean, that's a topic in itself I suppose, but we've also seen the same problem with the gabapentinoids that kind of peaked probably more five or 10 years ago. We all saw that as people started getting concerned about opioids, that people started prescribing gabapentinoids more commonly and for conditions that it really wasn't appropriate for, but because there was this pressure to give them something we do know that it can also cause issues of dependence. There is some concern that it adds to the risk of opioid overdose, particularly when people are sort of taking high doses of some of the gabapentinoids.

I guess it's really all about agent selection, but mainly thinking about beyond that about really what the cause of the pain is and how to best deal with it.

Absolutely. And we haven't really gone into too much detail in this paper and also setting a limitation on your opioids. One of the advances I suppose we made in the last few years is this advocating of setting the limit of the 100 mg morphine equivalent per day is a sort of ceiling dose. That was really very, very helpful, because we do know that as the doses escalate to get up to those higher doses, the risk of overdose really escalates. There was one big Canadian study that if you're on more than 200 mg morphine equivalents a day, your risk of opioid harm triples compared to someone who's on less than 20 mg.

That's multitude of reasons. Paradoxically patients who are on higher doses are actually at greater risk of ventilator impairment. Although you develop tolerance to the analgesia of opioids, you don't develop so quickly tolerance to the ventilator-impairment effect of opioids. We tend to think that patients on high doses are immune to ventilator impairment, but in fact, they are probably more vulnerable. And so we have to be very, very careful with these patients on high doses of opioids.

I guess things can escalate very quickly from that 20 to 200.

Yeah, we certainly do see it.

How do we actually deal with that progression in terms of dosing? I guess what we'd like to see is to be able to see deescalating opioid doses in the postsurgical period. How do we manage that in practice?

Definitely it is a challenge. You often have patients who just do not have the coping skills and are difficult patients to manage. And those are the ones that usually escalate, they've usually got significant other psychological issues to deal with as well. And they can be very, very problematic. And that's certainly why when things are going in the wrong direction, that's why more and more are advocating referral to a pain management specialist, get some help kind of thing because it can escalate very, very quickly and people can feel like they have to do it. But if you get someone else to give you a hand, then that was certainly going to be a good strategy for these patients.

Obviously you've always got to be ensuring that you've eliminated or excluded possibility of some new pathology going on. And we've sort of mentioned about that. Occasionally there are new things going on that the cancer's recurred or whatever. And so we need to be cognisant of that as well.

We've talked about high-risk patients and we've talked about setting expectations, but I guess in the patients where perhaps some of those things aren't immediate issues, is there advice on how we might go about structuring an opioid wean for patients? How that gets managed in practice? Who should be managing and watching this weaning protocol from the patients?

I think in the uncomplicated patient, someone who's had a knee replacement, for example, it's not uncommon for them to come out of hospital on still quite significant doses of opioids, often long-acting as well. If the clinician feels it's within their skillset, then that's not unreasonable to wean them yourself. That wean will need to match the expected reduction in pain or sensory inputs that you're expecting. And that's often a judgement thing. But generally it's over a week or two, for example, after knee replacement, most people can be weaned down. That weaning process, we've put some guidelines there. There's no hard and fast facts. Some people can be weaned quicker than others.

Certainly when I was doing chronic pain management patients would tell you how they would run out of their high doses of OxyContin and they'd just come off it straight away, and, "Did anything happen to you?" "Oh, no. Not really." It's quite variable and others that seem to be exquisitely sensitive to weaning. There's no hard and fast. It's a lot of just see how the patient goes, but we've put a number there of 25 to 40% every few days. I think that's a reasonable baseline for people to start at. Again, if you feel like you're out of your depth, then it's always best to seek the advice of someone else as well.

Yeah, absolutely. What about the patient where this isn't going well, and I guess I'm thinking obviously it involves referrals. What are those kind of alarm points where this is something which we really need to get a pain physician involved in?

I think alarm points would be certainly those patients who are known to have high rates of postsurgical pain that we've mentioned about, so someone for example who’s had an amputation, mastectomy, thoracotomy, those, we sort of flag. There are certain subsets of patients that we've mentioned about who are higher risk. These are usually patients who've got a family history of ongoing pain. They've had a previous history of ongoing pain after injury that lasted longer than normal. They've often got unhelpful psychology, anxious patient that catastrophises.

You certainly want to be cautious or the flag would also be for those patients who have got risk factors for opioid abuse. They will be patients who've got a history, either personal or family history, of other substance abuse or alcoholism, elicit substances. They often also have a strong history of significant psychiatric illness, schizoaffective disorders, depression, ADHD, those we’d sort of flag, patients of yeah, I'm expecting these patients to be difficult and they would be the ones that would be very, very sort of low threshold as it were for keeping an eye on things. Initially also to try and prevent things from escalating.

Well, I'm sure we can all work on trying to pick those patients at greater risk and really thinking about the whole patient.


Gavin, this has been really great chatting to you. Thank you so much for joining us on the podcast today.

Thank you for having me, David.


The views of the guests and the hosts on this podcast are their own and may not represent Australian Prescriber or NPS MedicineWise. I'm David Liew. Stay safe and thanks for joining us once again.