Latest / European Society for Vascular Surgery / Analgesia Management Before, During And After Major Limb Amputation

Transcript

Analgesia Management Before, During And After Major Limb Amputation · European Society for Vascular Surgery

0:12
Good afternoon and welcome to the ESVS podcasts.
0:16
I'm Justin Woolgar and today we will be discussing
0:20
a topic that is probably one of the less glamorous
0:23
aspects of vascular surgery but still very important
0:27
and that is amputations. and more specifically,
0:31
pain management. Despite our heroic efforts and
0:35
attempts at limb salvage, the situation often
0:38
arises where the only solution is an amputation.
0:42
These patients are often in a desperate place,
0:45
as ischemic pain is notoriously difficult to
0:49
manage. As if things could not get any worse
0:52
for these patients, their pain management after
0:55
amputation is further complicated by not only
0:59
the discomfort of having one's leg amputated,
1:03
but also by various neuropathic and phantom pains,
1:07
which I know very little about. Fortunately,
1:11
I'm joined by someone who does, and happens to
1:15
also work not a million miles from me, Mr David
1:19
Bosanquet, consultant vascular surgeon. at the
1:23
South East Wales Vascular Network in Cardiff,
1:27
UK. Dave Bosanquet, welcome to the ESVS podcast.
1:33
Thank you for having me on. First off, both of
1:38
us are practising vascular surgeons and we are
1:41
all too aware of how much pain these patients
1:44
frequently have. My question is though, what
1:48
are the main types of pain we see before and
1:51
after amputation? And why is this so difficult
1:54
to manage? Yes. Yeah. Pain after amputation is
1:59
really important. We actually did a piece of
2:02
work a few years ago looking at what are the
2:04
top research priorities within the field of amputation
2:08
surgery and improving pain outcomes was right
2:12
at the top. I think it was number four. So pain
2:14
management for these patients is so key and critical.
2:19
The types of pain. that these patients suffer.
2:22
So there's the classic, isn't there? There's
2:24
phantom limb pain, which we all know about. It's
2:27
sensations that are felt in the limb that's been
2:31
amputated. They're painful. There's also stump
2:35
pain or residual limb pain. So that's pain that's
2:38
felt at the site of the residual limb. That could
2:42
be due to a surgical site infection. It could
2:45
be due to ischemia. It could be due to a wound.
2:48
Maybe there's a prosthetic issue. And then there
2:51
is the musculoskeletal pain that these patients
2:55
struggle with as well. Back pain, hip pain, the
3:00
pain and discomfort of the mechanical changes
3:04
that the body has to make to adapt to moving
3:07
through the world with only one limb. So these
3:10
are the three types of pain. And I think it's
3:12
because it's difficult for us sometimes to disentangle.
3:16
what pain a patient is complaining of if we are
3:19
not careful with our history taking. And then
3:21
there's a battery of various drugs and treatment
3:23
options that we have available to us. And that's
3:26
part of the challenge of treating amputees and
3:29
their pain. I guess as surgeons, you know, we
3:34
probably don't know too much about pain management
3:37
as our anaesthetic colleagues, which I suppose
3:40
can cloud. one's judgment or one's knowledge
3:44
or experience in this field. Suppose we do not
3:49
get perioptic pain management optimized. Is there
3:52
any evidence that this can adversely affect long
3:55
-term outcomes in amputees? Yes, yes. So the
4:01
pain management around the time of surgery is
4:04
critical because we know that if you have increased
4:07
pain pre -optively, And also, if you have increased
4:10
pain in the immediate perioperative period, that
4:14
predicts for worse, longer phantom limb pain
4:19
and other such pain. And I completely agree with
4:21
your first point, Justin. The issue is, is that
4:24
we need to work as an MDT here. It needs to be
4:28
that the surgeons and the anaesthetists and the
4:31
pain specialists work together to come up with
4:34
individually the best treatment options for.
4:37
the patient that comes through the door. If we
4:42
look at pre -operative pain management, and I'm
4:46
going to be showing my age in a minute, I can
4:47
certainly recall about 20 years ago, there was
4:50
a vogue for inserting epidural catheters in amputation
4:55
patients pre -op. Does pre -existing pain influence
4:59
post -operative pain and phantom limb pain? And
5:04
is there any evidence that analgesia strategies
5:07
should begin preoperatively? Yeah, really good
5:11
question. I mean, yes, so we know that it makes
5:16
sense to reduce the pain preoperatively. That
5:20
would make sense, wouldn't it? If we know that
5:22
increased pain preoperatively predicts for worse
5:24
outcomes, it would suggest that that is a place
5:26
that you can target pain and improve long -term
5:30
outcomes. I would say that the evidence for epidurals
5:33
is... partly there but it's not overwhelming
5:36
so for example i believe there's a 65 patient
5:39
rct which does suggest that if you give an epidural
5:43
or if you give something else pre -operatively
5:46
which can improve your pain experience then you
5:50
do get improved outcomes in terms of phantom
5:52
pain afterwards i guess the challenges with epidural
5:57
are actually myriad right you have issues such
6:00
as there's risks to them There's the challenge
6:04
of actually finding an individual who's got time
6:07
and space to insert them. The timeline for these
6:11
amputees, quite often what happens is when patients
6:14
are teed up for an amputation, certainly in the
6:17
emergency setting, they are then booked into
6:20
theatre within the next 24 to 48 hours. So sometimes
6:23
there isn't this protracted time where you can
6:26
provide an epidural and then have a gap before
6:29
the amputation. epidurals in general have fallen
6:36
out of favor you know we're in the enhanced recovery
6:38
after surgery type era and so we want our patients
6:43
up mobile engaging with the physiotherapists
6:46
and epidurals certainly post -op have a risk
6:49
of slowing the patients down yeah thanks for
6:53
that i i totally agree with you uh about the
6:57
you know amputations which often occur in the
7:00
middle of the night you don't really have much
7:03
time for an MDT discussion with the anaesthetist
7:05
to optimise and find out what's the best way
7:08
of treating an individual's pain prior to an
7:13
amputation. But it is food for thought. And I
7:18
guess with best practice, this is something that
7:21
perhaps we ought to be looking at in the future.
7:25
But it's all resource intense, as you well know.
7:32
Can I just really quickly bounce back on that?
7:34
There was a recent Delphi study within the UK
7:36
looking at pain management practices around the
7:40
time of amputation surgery. It was Patrice Forget
7:44
from Scotland who was led on that. One of the
7:47
questions was about epidurals and amputation
7:50
surgery. And that was one of the statements that
7:52
couldn't reach consensus. The statement was along
7:54
the lines of, you know, we should be looking
7:56
towards more routine use of epidurals. And that
7:59
failed to garner. 50 % agreement. So it was less
8:05
than 50%. So that's clearly an area that within
8:08
the UK, we don't have a definitive answer as
8:13
to the best use of epidurals. And I would say
8:18
that anecdotally, it's only a handful of centers
8:20
that routinely reach for an epidural prior to
8:23
an amputation in the UK. Yeah, it'd be interesting,
8:26
wouldn't it, to know what people's practice is
8:30
in other centres and other places around the
8:33
world. I mean, you know, obviously yourself and
8:36
I are UK vascular surgeons, but obviously, you
8:42
know, the ESVS reaches, you know, a substantial
8:46
audience, not only in Europe, but across the
8:49
world. And it'd be interesting to know what people's
8:52
experiences are dealing with this type of problem
8:55
in different centres. And again, just to bounce
9:00
off that comment as well, yeah, so a recent meta
9:02
-analysis was comparing general anaesthetic versus
9:05
regional anaesthetic of any type, you know, so
9:08
it could be an epidural, it could be a spinal
9:11
or various other types of regional anaesthetic.
9:14
GA accounted for a bit over 80 % of all these
9:18
patients, so thousands of patients, about 10
9:21
papers that were being reported. And so within...
9:24
those cohorts and those countries where those
9:27
papers have come from, the vast majority actually
9:30
get GAs. Moving on to something I know has a
9:34
special interest of yours, Dave, perineural nerve
9:37
catheters placed at the time of surgery. Can
9:41
you tell us more about these and are there any
9:44
advantages of using a continuous blockade with
9:47
a perineural nerve catheter as compared to, say,
9:50
a regional nerve block or epidural? Yeah, thanks.
9:54
And it's very topical that we're talking about
9:57
this because, in fact, the very first time I
10:00
saw an interruptive nerve catheter used was when
10:03
I did my training and when I came through your
10:05
unit in Swansea, Justin. So I'm very grateful
10:08
for that. And it's lovely to be able to talk
10:11
on it now. So, yes, nerve catheters placed at
10:14
the time of surgery. So this is an above knee.
10:16
This is to the sciatic nerve. And for a bologna,
10:19
this is to the tibial nerve. These are. Small
10:22
catheters, we typically use the epidural kit
10:25
to thread a small catheter next to the nerve
10:27
or with inside the nerve and then infuse local
10:31
anesthetic. And I guess that from a logical and
10:36
theoretical point of view, it would make sense
10:38
that that should improve pain outcomes. And certainly
10:42
the best meta -analyzed data that we have suggests
10:46
that it does reduce opioid consumption, which...
10:50
is an important thing for us to try and do, and
10:53
also probably reduces acute pain. Now, that said,
10:56
the quality of data that's currently out there
11:00
is really rather poor. So this is a technique
11:03
which actually is used quite frequently in certain
11:05
countries. Within the UK, it's probably around
11:07
the 75 % to 80 % level, but the evidence base
11:10
to back it up that it does actually improve outcomes
11:12
is relatively flimsy. Yes, I think I can remember.
11:19
A few years ago, when we started putting in epidural
11:23
catheters, it seemed to make sense. I mean, sometimes
11:27
the anaesthetist place an ultrasound guided block
11:30
or catheter prior to amputation, either in the
11:33
anaesthetic room or occasionally on the ward.
11:36
What about the role of ultrasound guided interventions
11:39
in these patients? Have you got any comments
11:41
on that? Yes, well, the published evidence on...
11:46
ultrasound guided blocks or catheters to the
11:49
major nerves is actually quite a lot less than
11:52
for surgical placed nerve catheters. But it makes
11:56
sense, doesn't it? You've got data from operating
12:00
on the leg in other territories and in other
12:03
fields, for example, in orthopedic surgery, which
12:07
does suggest that if you target the nerve supply
12:10
in the leg, that you have improved pain outcomes.
12:14
So, yes, there are a number of anaesthetists
12:17
who will either block with a single shot block,
12:20
let's say the femoral nerve, if you're doing
12:22
an above knee amputation, or they may place an
12:25
ultrasound guided catheter. They may place an
12:28
ultrasound guided sciatic catheter if you're
12:30
doing a below knee amputation. Sometimes these
12:35
blocks and catheters are to reduce the amount
12:39
of pain solely. So that just for analgesia. But
12:43
sometimes they're actually used as the sole anesthetic,
12:46
particularly in patients who are quite high risk.
12:48
So there is low quality, poor quality data that,
12:52
first of all, you can use these to take a patient
12:55
through an entire amputation if they're too high
12:58
risk for GA and neuroaxial techniques. And there's
13:03
also some evidence that they do improve pain
13:06
outcomes. if you use them as an adjunct to your
13:10
general anaesthetic or whatever else, whatever
13:12
you do for an anaesthetic. I think we always
13:17
curse the anaesthetists for taking so long to
13:20
put their blocks in, but I think we all have
13:22
to realise that they are for patient benefit
13:25
at the end of the day. As we are discussing perineural
13:29
nerve catheters, I have to ask about the placement
13:32
trial, which... you are chief investigator for.
13:36
Can you tell us more about this and what questions
13:39
it's hoped to answer? Yes, thank you. So the
13:43
placement trial is a trial to answer the question
13:47
of surgically placed nerve catheters, do they
13:50
impact patients in terms of acute pain and also
13:54
longer term pain up to six months. And so we
13:58
secured funding from the NIHR to look at 650
14:02
patients. who are randomized 50 -50 to either
14:06
receive or not receive a nerve catheter. And
14:09
for every patient within the trial, they get
14:12
the best perioperative analgesia and anesthesia
14:17
otherwise. So they get the anesthesia that is
14:21
best for them. You're allowed to place ultrasound
14:24
-guided blocks and catheters, if you wish, in
14:27
either arm. You can inject the nerve with local
14:30
anesthetic or not, as you see fit. We will capture
14:35
acute pain up to five days. That's our primary
14:37
outcome. And our secondary outcome will be looking
14:40
at phantom limb pain and such outcomes up to
14:42
six months. So placement is a critical trial
14:47
because it's going to be one of the largest randomized
14:50
controlled trials within the sphere of amputation
14:54
surgery. And we'll provide some robust evidence
14:58
as to if surgical placed nerve catheters are
15:01
a benefit or not. Moving on to a different topic
15:06
slightly, a lot of these patients are on a cocktail
15:09
of analgesics such as opioids, non -steroidals,
15:12
paracetamol, etc. How effective are these multimodal
15:17
regimes and how should we prescribe them? And
15:21
what about drugs such as gabapentin and pregabalin?
15:26
Yeah, that's a really interesting question. So
15:29
the first thing to say is that multimodal pain
15:31
relief is considered gold standard. It just is.
15:34
So there are numerous guidelines which for outside
15:38
are much more all -encompassing rather than just
15:42
amputation surgery. And in broad strokes, they
15:44
all suggest multimodal therapy. Within the Delphi
15:48
that I mentioned previously, it was very much
15:52
agreed that we should be treating patients in
15:54
this multimodal way. So this is clearly recognised
15:57
as the way to go. Opioid sparing. it's typically
16:02
a phrase that you will find when you're treating
16:04
these type of patients so you do want to minimize
16:06
the amount of opioids that are available that
16:10
sorry the patients need there are there's scope
16:15
for using NSAIDs in appropriate patients to improve
16:20
their symptoms that they're getting And you mentioned,
16:25
well, pregabalin and gabapentin. I think it's
16:28
worthwhile picking up the gabapentin specifically.
16:31
We had a careful look at gabapentin recently.
16:35
And what we found is that whilst it can be used
16:39
in the postoperative period to treat phantom
16:41
limb pain, but there's no good evidence that
16:43
we should be starting it routinely for everybody
16:45
preoperatively. And there's a similar type of
16:48
finding with ketamine. This is another drug.
16:50
which people do sometimes reach for when they're
16:53
struggling with postoperative symptoms. But there's
16:57
no good evidence that routine ketamine use before
17:00
surgery improves outcomes. So yes to multimodal.
17:05
Yes to opioid sparing. Consider your NSAIDs as
17:10
long as it's appropriate for the patient population.
17:13
But there's certain drugs which shouldn't just
17:15
be given carte blanche routinely to everybody
17:16
pre -op. And I would put... carbapentin and ketamine
17:20
in that bracket. Thanks for clarifying that,
17:25
Dave. I guess I suppose that pain begins and
17:32
starts in nerves. So if we're doing an amputation,
17:37
then the problem we need to deal with is at the
17:42
nerves. Are there any developments that you're
17:45
aware of? that are coming along which describe
17:50
techniques that directly involve dealing with
17:54
the nerve problem, which can, as you know, become
17:58
problematic in patients with amputations. Yeah,
18:02
absolutely. I mean, this is such a critical issue
18:06
with these patients. So as soon as you divide
18:08
a nerve, it will start to try and heal itself.
18:12
And invariably, it will form some type of neuroma.
18:16
So standard teaching for amputation surgery is
18:21
to want to take a traction neuroectomy. The nerve
18:23
is pulled down. The nerve is cut high. The idea
18:26
is it springs out of the operative field. It
18:28
minimizes the inflammatory response that occurs
18:31
around it. If it does create a neuroma, the idea
18:34
is it's buried deep within some tissue somewhere.
18:38
But that's relatively simplistic. And so there
18:40
have been lots of studies. What can we do to
18:43
reduce the risk of neuroma formation? Can we
18:45
cauterize it? Can we inject it with various substances?
18:49
Can we cap it with epineurin? Can we bury it
18:53
in bone or in muscle that's presently there?
19:01
What can we do? And essentially, lots of... Techniques
19:06
were tried and none of them showed any promise
19:08
over and above traction anorectomy. And so traction
19:11
anorectomy should certainly be viewed as the
19:13
gold standard and the basic way of undertaking
19:18
the division of the nerve. Over the last few
19:23
years, a couple of surgical techniques have come
19:26
onto the block. This is from our plastic surgical
19:27
colleagues. So we have RPNI and TMR. So RPNI,
19:33
regenerative peripheral nerve interface, takes
19:37
the nerve and what it does is it takes some non
19:41
-innovated muscle and you take the nerve and
19:46
you wrap the muscle around the nerve. It has
19:48
to be non -innovated. That muscle has to have
19:51
been taken away from the innovation which it
19:53
currently has. If you place a nerve within muscle
19:56
that's already innovated, It doesn't have an
19:59
area to grow into, but if it's not innervated
20:01
by nerve, then the idea is that as the nerve
20:05
heals, it will heal into the muscle and it will
20:08
actually create connections to that muscular
20:10
tissue itself, which will then support more ordered
20:13
firing rather than disordered firing in the symptoms
20:16
with neuromas. And so RCTs have demonstrated
20:21
that this can be a very effective treatment for
20:23
symptomatic neuromas, RPNI. as well as potentially
20:28
for patients having primary amputations. The
20:33
other plastic surgical technique that has come
20:37
onto the scene over the last few years is TMR.
20:41
So this is targeted muscle re -innovation. And
20:44
the idea is you find a motor nerve, which is
20:48
going to a muscle, and you divide that motor
20:51
nerve, and then you attach the cut end of the
20:55
nerve to this. to this motor nerve and so again
20:59
the idea is that rather than the disordered sprouting
21:02
of this nerve it has somewhere to go and actually
21:05
ends up innervating that muscle and the idea
21:08
is that it reduces pain and again subject to
21:11
RCTs and suggesting that there's reduced pain
21:14
when treating symptomatic neuromas and potentially
21:18
also for primary amputees. I think the next few
21:22
years are going to be quite interesting when
21:24
the results of these procedures start to emerge
21:28
and be very interested to hear how successful
21:33
they are and how they develop. They do sound
21:36
very interesting techniques. I know in a few
21:40
months time, we will be publishing the ESVS amputation
21:44
guidelines, which you have also been involved
21:47
in. Without giving too much away. What are the
21:52
areas of controversy in this area and what are
21:56
the unanswered questions in chronic post -amputation
21:59
pain and perhaps some of the controversies of
22:04
amputations in general? Yeah, thank you. Well,
22:08
probably actually the role and scope of TMR and
22:13
RPNI is certainly a big question mark in my mind.
22:19
They're techniques which have real promise. And
22:21
yet, if we were to ask vascular surgeons across
22:26
the globe to undertake these routinely for their
22:28
amputation operations, I think that would be
22:31
really challenging to implement. And so there'd
22:35
be lots of questions to be asked. So where exactly
22:38
should these techniques fall? Is it for highly
22:42
selected patients? Is it only for patients with
22:45
symptomatic neuromas? Should it be done for primary
22:47
amputations, et cetera? I think another question
22:50
that's going to come up is what is the best local
22:55
anesthetic technique? So we've talked about surgical
22:58
placement nerve catheters. We've talked about
23:00
ultrasound -guided nerve catheters. We've talked
23:03
about ultrasound -guided blocks. It makes sense,
23:05
local anesthetic, but how is it best to be delivered?
23:09
And is there any evidence that... one technique
23:12
is better than the other and i think if it's
23:16
okay if i can just go slightly left field it's
23:19
like night moves thinking but when we're talking
23:21
about controversies and things of interest within
23:23
the guidelines it'd be remiss of me not to talk
23:25
about through the amputations i think that through
23:28
the amputations are a bit of a vascular surgeon's
23:33
blind spot it's one of these operations where
23:36
certainly during my training i'd Heard about
23:39
and maybe seen one or two patients with, but
23:42
it wasn't commonly thought about as a realistic
23:45
amputation option. It's either below knee or
23:48
it's above knee. That's the typical way of approaching
23:52
these type of patients. But what I noticed as
23:55
chairing this group and being part of an international
23:59
multidisciplinary team is there are a lot of
24:02
voices from various different specialties, from
24:06
various different countries as well. saying that
24:08
through knee amputations are perhaps overlooked
24:12
and that is to the detriment of patients. So
24:17
it may well be that there is a significant cohort
24:19
of patients who would be suitable for and would
24:23
garner significant benefits from a through knee
24:25
amputation over and above, let's say, an above
24:28
knee amputation. Within the UK, we've actually
24:32
got an RCT, the Hamlet trial running, which compares
24:35
these. two amputations, through knee and above
24:38
knee. But there's lots of questions about through
24:42
knee amputations. Who are they best suited for?
24:45
Are they best for the young athlete who had a
24:48
traumatic amputation? Or are they maybe suited
24:51
for an older amputee who is less likely to ambulate
24:55
but wants a better sitting balance, et cetera,
24:58
et cetera. And then there's a technique of how
25:00
you undertake a through knee amputation. So I'm
25:03
delighted to say. There's going to be many, many
25:05
years and decades of amputation research which
25:08
needs to happen in the coming years. Yes, I think
25:13
you're probably right. You know, I must admit,
25:16
being a bit of a dinosaur, I've always gone for
25:19
either below knee or above knee. And I think
25:22
through knee amputations do certainly have their
25:26
place. And it'd be interesting to get more evidence
25:29
on them. The issue with through -knee amputations,
25:34
which probably has led to them having a bit of
25:37
a bad reputation, is the technique. And I think
25:39
as soon as we can iron out what's the best way
25:42
of doing it and everybody is singing from the
25:44
same song sheet, I think we will probably find
25:46
that the through -knee amputation does produce
25:49
the results. And it certainly is, from a rehabilitation
25:53
point of view, is certainly a better option.
25:56
Perhaps a discussion for another day. Finally...
26:00
Most of our patients requiring amputations in
26:02
our unit, and I'm sure it's a similar case in
26:05
Cardiff, present as emergencies. In your opinion,
26:08
what would be the ideal analgesic pathway for
26:12
these patients? Yes, thank you. So we have recently
26:20
started using more and more preoperative sciatic
26:23
place nerve catheters for patients who present
26:26
with severe pain, chronic limb threat and ischemia.
26:31
And so I would say that if someone was in pain
26:33
and was struggling with other means of controlling
26:38
their pain, I think a pre -operative ultrasound
26:41
guided sciatic catheter would be very welcome,
26:45
not only just to reduce the pain, but also to
26:48
elevate the limb to reduce any edema. I think
26:51
the difference between general surgery and a
26:54
neuroaxial technique. is an individual discussion
26:59
with the patient. So I want an anaesthetist who
27:01
is able to offer both. And I think that I can
27:05
see the theoretical benefits of an ultrasound
27:08
guided nerve block to nerves which a surgeon
27:12
is never going to get near in amputation surgery,
27:15
such as the femoral nerve. And I can see theoretical
27:19
and randomised evidence supporting. placing a
27:25
surgical nerve catheter. So I think that's probably
27:28
how I would suggest as your optimal pathway intraoperatively.
27:33
I think the traction neurectomy has to be standard
27:37
care at this precise point in time. It's worthwhile
27:40
pointing out it's not just the sciatic nerve.
27:43
It's not just the tibial nerve that we're dealing
27:44
with. You've also got the saponis nerve. You've
27:47
got the sural nerve. You've got the perineal
27:49
nerve. All of these really should be dissected
27:52
out. and cut under traction and maybe inject
27:56
with a bit of local anesthetic as well, as is
27:58
my standard practice. And then postoperatively,
28:01
it would be a matter of an MDT type decision
28:03
as to what is the best medication for these patients
28:08
to be on, but certainly moving towards an opioid
28:10
sparing multimodal analgesic combination. Well,
28:18
I think that's about all we have time for. Dave
28:21
Bozenkett. Thank you for your time and taking
28:23
part in this podcast. I think our listeners will
28:26
find this discussion very useful and informative
28:29
on a topic that probably does not get the attention
28:33
it deserves. Thank you very much and all the
28:37
best. Well, thank you. It's been a pleasure.
28:39
If you would like to listen to this podcast again
28:42
or any of the other ESVS podcasts, you can download
28:47
them on Apple Podcasts, Spotify. and from the
28:51
ESVS Library. Until the next time, bye for now!