Our first speaker is Dr. Kodsi.

He's an Australian-trained adult medicine physician who qualifications in palliative

medicine and pain medicine.

He has a special interest in musculoskeletal and neuropathic pain,

survivorship medicine, coordinating chronic and complex disease conditions,

cancer pain, comorbidity of pain with addiction.

Today, Dr. Kodsi will be speaking

about Chronic pain, post-surgical pain management. Thanks, Dr. Kodsi.

Let me start with a story, one that might be familiar to many of you in general practice.

Margaret's a 62-year-old retired teacher who's always been independent,

active and stoic when it comes to pain.

Six months ago, she underwent a routine mastectomy for early stage breast cancer.

The surgery was uneventful and her oncologist declared her cancer-free.

But Margaret hasn't felt free. She tells you, her GP, I still have this burning,

stabbing pain along the scar and into my armpit.

I can't sleep on that site. I can't wear a bra.

I can't even hug my grandchildren. It hurts.

You've checked the site. It's clean. No signs of infection.

Her surgeon says that the wound has healed. Her oncologist has moved on. But Margaret hasn't.

This is chronic post-surgical pain. It affects about half of patients undergoing

high risk procedures such as a mastectomy, thichotomy or an amputation.

It still occurs with hip and or other orthopedic surgeons but much in a much

less degree to about 15% and the most common place that it's diagnosed,

it's not in the theatre or the ward, it's in your office.

So today we'll be exploring chronic post-surgical pain and why it happens and

more importantly how we can all have a role in trying to prevent it together.

So hi everyone, I'm Anthony Kodsi, I'm a pain specialist and a palliative care

physician, otherwise known as an unofficial human complaint sponge.

I didn't always work in pain, I started general medicine, then I did palliative

care, but somehow along the way I kept being called into situations where the

patient was in pain and no one knew what to do next.

Eventually I realised that's my job now.

I often say that I meet patients when hope is waning thin and they've had the

surgery, they've done the rehab, they've tried the medications and the pain's

still no good. Or worse, it's even worse.

I lead the pain department in Concord Hospital and I work across tertiary hospitals

and I work alongside with the orthopedic surgeons here.

And I work in both interventional pain and supportive care.

My job is to step in when it starts to intrude on people's recovery or their life.

But ideally, we don't wait for that moment. Ideally, we can collaborate early,

before surgery, before opiate escalation, before the neural pathways lay down its tracks.

That's why I'm here today, because you as GPs are not only the first port of

call, you're the most consistent voice of patients here.

And that puts you in a very powerful position to change their trajectory.

Because the best chronic pain story is the one that never happens,

the one that doesn't need to see me.

So what do pain specialists do because I

believe that sometimes there is

a bit of misunderstanding or it's not

well known what we do I do a lot of medication management counseling and deprescribing

I help try to work out undifferentiated cases and some patients have had orthopedic

surgery and they had quite a good success structurally and good range of motion

but they still have persistent issues.

So I try to assist alongside with the orthopedic surgeon in that scenario.

I do diagnostic and therapeutic nerve blocks. I do some regenerative medicine

work. We have the facilities.

It's not always employed and there's a bit of difficult literature to go through

to know which ones work best for which type of joints.

Botox for refractory, spasticity and nerve pain and migraines particularly.

Where you could see ablation pulse treatments and neuromodulation.

And I work alongside you, the general practitioner and also the patient in a shared decision model.

Most patients, the chronic pain that they have is not an indicator of harm and

they should be able to mobilize and move.

And a lot of patients have had incomplete rehabilitation after their surgery

and they believe that pain had been a hindrance to that.

So they all quite benefit from physical therapies, exercise or prescribed activity.

And clinical psychologist because the burden of mental health problems with

chronic pain patients is very severe and significant.

So a bit of a history about chronic post-surgical pain.

So a seminal paper by Sherman et al.

40 years ago had a comprehensive mail questionnaire that was sent to 5,000 US

military veterans with limb amputations.

55% responded. This seminal survey showed a few findings.

Phantom limb pain was very prevalent.

About 78%, four-fifths of patients experienced phantom limb pain.

Most of them had a lot of disability from this phantom limb pain.

It didn't go away, no matter where it happened.

And a lot of them had coexisting stump pain. In fact, it was very rare to have

phantom limb pain without coexisting stump pain.

And what was surprising, since I've only been a doctor for about 15 to 20 years,

is that most of the treatments that they've all tried are very similar to what

we have today, 40 years later.

And only less than 1% reported lasting benefits from treatment.

So this kind of shows a really high prevalence and functional impact of chronic

post-surgical pain despite that the surgeons made sure that there's no other

underlying structural issues are gone and they treated anything that they could see.

Another seminal paper was a study 10 years later by Crombutyl and they had a

survey of 5,000 patients.

Sorry, this is too loud.

Of 10 chronic pain clinics in Northern Britain.

And they looked at the frequency of how many patients in the pain clinics were

due to surgery or trauma.

And they found about one-fifth of patients had surgery beforehand and is why

they're in the pain clinic.

So this is a very high prevalence of post-surgical pain issues.

And most of them didn't have any other underlying pathology.

The surgeons cleared them and they still had persistent pain.

This also is a study that showed that the demographics between the surgery-related

pain and those who had trauma-related pain were quite different and stark.

So, 10 years later, before the ICD-11 and ICD-10 and other diagnostic manuals,

they're starting to coin the word chronic post-surgical pain.

And most of them try to reclassify them to other types of what surgeries they

had because they had very different risk profiles.

And arthroplasty also was seen as well.

And most of it defines pain as that persists three months after the recurrence

or persistence of the pain. So it has to stay for longer than three months to

be considered chronic post-surgical pain.

And it began or increased after surgery, usually in that very post-operative

window or in a few months after the surgery.

It's in the area of the surgery and it needs to be going on for three months.

And they've excluded the most common causes, which is usually infection,

the pre-existing condition, and the NCR and ER of alternative cause.

The reason why this is different from acute pain is that acute pain is a physiological

response to tissue injury.

It is protective and it's usually time-limited.

Chronic pain, on the other hand, involves neuroplastic changes that sustain

pain long after tissue healing, and I'll be talking about that in a minute.

The pain persists without ongoing noise-disceptive input, suggesting that there

is central mechanisms of wind-up and loss of descending inhibitory control.

So what happens? So interestingly, in the preoperative phase,

people are set up to have failure and to have chronic pain.

The odds ratio for certain demographic behaviours that are biologically not

under anyone's control is being female, being younger sex, and having coexisting

or chronic pain issues to start off with.

Also psychological distress, being prone to catastrophic beliefs,

Catastrophic beliefs have been probably the number one thing that's been now

starting in the last 10 years Of trying to reduce that preoperatively to see

if that improves and stops bad post-surgical outcomes,

Unfortunately, most education and other interventions have not shown to really

benefit or is either prohibitively too costly.

The other thing that I'll talk about in a second is preoperative opioid use.

And then after the postoperative period in our pain rounds, we look at these

type of things, whether they had catastrophic beliefs there and we give them education.

We look at also the other things. In the preoperative planning stage,

I often talk to the anaesthetists about what their usual protocol or regime is,

their regional blockade to try to reduce central sensitization and what kind

of adjuvant analgesics can decrease wind-up pain.

The surgical technique is also important.

Preoperative opioids have been shown to have a very strong negative impact on a patient's recovery.

It affects infection rates, readmission, prolonged stay,

it causes higher costs and complications and longer hospital stays and they

have worse pain and functional outcomes and it's not very clear that the opioid

use just signifies that they have severe pain or a problem to start off with.

It's really just the opioids.

And tapering and multimodal strategies have been always suggested to try to reduce the risk.

In fact, if you reduce the opioids by about 50% within two to three months before

their operation, their risk is substantially decreased and they usually behave

like the baseline population.

The incidence per procedure is quite significant.

And for our purposes today, amputation and hip arthroprasty and knee arthroprasty

still have significant risks of chronic post-surgical pain.

The surgical risk factors is not surprising at all.

High tissue trauma surgeries have quite significant rates of chronic post-surgical pain.

Nerve injury during surgery is another factor and adequate acute pain control.

And surgical techniques, a study by Melko et al looked at prophylactic in the

inner nerve excision during hernia repair.

This is a famous study, and it found actually, interestingly,

that if you excise the ingling nerve, there was less pain than just preserving

the ingling nerve and it being under pressure by the mesh.

So surgical techniques are always in every kind of field of surgery.

There's always ongoing discussions about how best to reduce the risk of nerve

injury and reduce chronic pain.

So the reason for chronic pain involves both peripheral things that happen in

the tissues and central sensitization.

Peripheral injury causes a release of inflammatory mediators,

particularly calcitonin receptor gene peptide, which lowers noisiceptive thresholds.

It causes sensitization of the existing noisiceptive fibers.

It causes more noisiceptive fibers. It causes collateral sprouting.

It couples with the sympathetic overflow, which also lowers,

again, the noisiceptive thresholds.

And where nerve is cut, there is a nervi neborum.

And central mechanisms also exist. Sensitization and other things that happen

in the dorsal horn of the spine increases its more input and trafficking of

noisiceptive signals and decreases dysinibutory control.

So I'm going to talk about a controversial subject, but I'll talk about what we seem to know so far.

We used to think preventative analgesia might be helpful, but there has been

a lot of fortunate research in that department and less is known about where

the place of preventative analgesia is.

What is less controversial is the use of pre-emptive analgesia.

So pre-emptive analgesia is treatment given prior to the incision.

Pre-emptive analgesia is giving

analgesia before and during and after the operation and the closure.

The idea is this, that during surgery there's a lot of noise deceptive input

and then there's less as the patient recovers from that first day and then they

get another phase of increased noise deceptive input, more swelling,

more inflammation, etc.

And the hypersensitivity that occurs if you measure it also follows that noise deceptive input.

If we just gave analgesia after the surgery, we might dampen that neurodeceptive

input for a little bit, but that hypersensitivity doesn't really shift.

If we gave pre-surgical analgesia, the idea is that they might not get much

hypersensitivity from any inflammation, etc., that occurs in the operation,

but they still will get hypersensitivity and that doesn't seem to improve outcomes

for chronic post-surgical pain.

The idea is that with pre-emptive analgesia,

analgesia given throughout the trajectory for both in the operation and after

closure that we can dampen or reduce or mitigate hypersensitivity.

How do we measure hypersensitivity? One thing that we often do is look for alodynia

by using a von Frey filament near the incision. So they're always quite tender.

But using a filament that shouldn't cause pain or is not that noxious,

if they feel allodyneed towards that, then they're likely very sensitized.

So a study, a nice study was done

by Levander-Home in 2005 looking at interoperative epidural analgesia.

This was 85 patients with colonic cancer resected. They had two interventions.

They all had epidural 30 minutes before incision and they had treatment between

the incision and closure and then second are after skin closure.

So all patients had a thoracic epidural catheter and both had IV and epidural infusions.

Some of them though would have the study medication and the others would have saline.

The consistent story is this.

That if they had epidural buprenorphine, sorry,

bubivacaine, and they had good analgesia postoperatively, their outcomes were very different.

They had better postoperative pain, they were able to mobilize and cough,

and this is surprising with epidurals because that caused hypertension and they

might have less ability to mobilize because of just having the catheter.

And they had decreased normally pain consistently.

They were able to do other functional outcomes postoperatively.

And the interesting thing is that they all had decreased hypersensitization.

So when they were tested, they had much less sensitization in the epidural groups.

And this had a translation effect months after the surgery.

Those that received preemptive analgesia had decreased rates of chronic pain six or 12 months later.

So in the orthopedic space, they don't often use epidural catheters.

They often do regional analgesia and that has been shown to be just as good

and might be safer than epidural catheters in reducing sensitization.

The other techniques that we use, using gabapentinoids,

etc., they had its place but it increases sedation risks and other problems

in the postoperative periods and their benefit compared to their risks,

haven't been shown to be something that we should be routinely using.

In the post-operative phase, me as a pain specialist often tries to reduce their

opioid use and look at their functional pain assessment outcomes rather than just the pain scores.

And I also look for whether they have neuropathic pain because when they have neuropathic pain,

they are more likely to benefit from a neuropathic agent to try to reduce their

pain and reduce their opioid consumption as well.

So I look for aledonia, I use the static and dynamic superficial techniques,

I use a pin or I use a toothpick or a clip,

I use a dynamic brush to see if there's a brush aledonia and I try to diagnose

whether they have neuropathic pain as a reason for their high opioid use postoperatively.

So opioids have a lot of risks that we'll discuss in the next slide.

I often try to use non-steroidals as well with the surgeon's permission,

particularly because it can affect healing.

That's always a contentious issue of discussion.

But a lot of surgeries have been shown that preoperatively even,

that high doses of lexamethasone or COX-2 inhibitor like celicoxib can reduce

their post-operative pain and outcomes.

So this is worth discussing with your surgeon.

Gabapentanoids, in some protocols,

gabapentanoids have been shown to be helpful preoperatively to be used,

such as with shoulder surgery, but they also have its own risk profile and in

the elderly particularly,

they're much less likely to tolerate it.

Ketamine has its place but also not always well tolerated and IV lidocaine for short term as well.

So, we have in the post-operative phase, we have a lot of options of opioids to use.

Because today we're talking about the elderly, I have a few things to say.

So fentanyl PCAs we often use because it's very short and it's more forgiving

in renal failure, which is very common in the elderly.

But it's not a great analgesic all the time because it has tachyphylaxis.

So I don't know if anyone has tritrated a fentanyl patch before and gone to

really high figures and not getting much pain relief.

That's a property of fentanyl that doesn't seem to happen with other opioids.

Another issue with fentanyl is because it has less euphoric effects.

Some patients don't seem to get much benefit until we switch over to morphine or oxycodone.

Morphine is very well tolerated still, but it has a more high incidence of nausea

and histamine release compared to oxycodone.

So oxycodone is preferred in many places.

That said, very quickly we try to transition them from pure opioid agonists

to pentadol or buprenorphine.

And you might have noticed in the last five years that you're getting a lot

of these post-op patients now on polexia and buprenorphine.

But I'll say another thing. Tepentadol in the elderly has a higher risk of delirium.

It also does seem to have a lowest seizure threshold, a bit more than other

opioids and maybe a bit less than tramadol.

It still has a bit of a small risk of increased constipation compared to the other things.

And Tepentadol in Australia at least is not very titratable.

In the United States, Tepentadol comes in as an oral syrup. It comes in 25 milligrams.

We don't have these things, and that limits its use in the elderly.

So in a few hospitals that I work with, terpentadol is not usually used for patients above 70 or 75.

Buprenorphine, though, there is increased and increased data and more studies,

particularly where I come from in Royal Prince Alfred, of using low doses of buprenorphine.

It seems to be much more tolerated. Now the reason to talk about both dipentadol

and buprenorphine and how this fits in opioid stewardship these days is these

are both what's called atypical opioids.

They are not pure opioid agonists and most of their mechanism for pain relief

does not seem to be just their new opioid receptor agonist activity.

It's more due to other mechanisms. That also decreases sensitization.

And so therefore, it's not yet proven

but there seems to be that if

we shift to these other less drugs not

only are patients less likely to misuse or

abuse them in the post-operative period or continue to use them months and months

later but it might have an impact in decreasing central sensitization in the

post-operative period and thus decreasing the risk of chronic post-surgical pain.

Another thing in the post-operative setting is

that sometimes patients have increasing opioid use even in the community after

they've been discharged and it's not explainable by believing that there might

be a missed pathology or that the surgeons need to look again as to what is occurring.

And that is diagnosed by a

higher index of suspicion and the pain usually is very diffuse and poorly localized

even beyond the surgical site and there's aladynia as I described on how to

test and there's a lack of response when you escalate the opioid.

So it could be neuropathic pain, that's the other differential and this usually

occurs when the pure opioid agonists are used as well.

So what do we do? I often try to rotate the opioid to try to mitigate the risks

of the opioid-induced hyperalgesia.

In the inpatient setting, I might use other treatments and in your setting,

anti-inflammatories and gabapentinoids might be beneficial.

So multimodal strategies are not only helpful in the intraoperative phase,

it is still useful in the postoperative and in the community setting.

And opioid sparing strategies like early rehabilitation is also important.

So takeaways, post-surgical pain is persistent and recurrent pain lasting more

than three months after surgery, after excluding other causes.

The risk factors for chronic post-surgical pain is not just the surgery,

it's also biological and demographic factors.

And in particular, there are multiple factors, particularly still under your

control, which is a preoperative opioid use and their psychological distress.

The surgical impact has a key relationship with their chronic post-surgical risk history.

There are preventative ways that both you and the anaesthetist,

and pain specialist can employ in putting multimodal analgesic strategies even

before incision and opioid management is important to mitigate the risks And

if we look at the opioid and be stewards for them,

we can also reduce possibly the chronic post-surgical pain history.

Okay. So, thank you.