Popliteal + Adductor Canal blocks not working for Achilles repairs

[soorg]

Hi. I've been having varied success and just plain straight-up weirdness with these blocks for Achilles repairs.

Had two the other day, both easy blocks, saw the LA spread around the sciatic (I'm injecting above the bifurcation), plus good spread in the adductor canal. 20 mL of 0.5% Ropi for the popliteal, with 10 mL of 0.25% Ropi for the adductor canal. After blocks, kept patients on 4% Et Desflurane. 50 ug fentanyl and nothing else during case. Zero change in vital signs throughout the entire hour-long procedure. Get to PACU and both patients are in pain! One complaining of heel pain, and the other just saying "I'm definitely not numb." Both were satisfied with 0.4 mg Dilaudid, and they were on their way. Still, how are they having pain?! Again, zero signs that the blocks weren't working during the operation, and only at 4% Desflurane. Healthy males for both. Grrrr...

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[anbuitachi]

Hi. I've been having varied success and just plain straight-up weirdness with these blocks for Achilles repairs.

Had two the other day, both easy blocks, saw the LA spread around the sciatic (I'm injecting above the bifurcation), plus good spread in the adductor canal. 20 mL of 0.5% Ropi for the popliteal, with 10 mL of 0.25% Ropi for the adductor canal. After blocks, kept patients on 4% Et Desflurane. 50 ug fentanyl and nothing else during case. Zero change in vital signs throughout the entire hour-long procedure. Get to PACU and both patients are in pain! One complaining of heel pain, and the other just saying "I'm definitely not numb." Both were satisfied with 0.4 mg Dilaudid, and they were on their way. Still, how are they having pain?! Again, zero signs that the blocks weren't working during the operation, and only at 4% Desflurane. Healthy males for both. Grrrr...

Test the dermatomes.
Adductors have higher fail rate imo bc easier to mess up

 

[UscGhost]

Don't think Adductor canal adds much value for a Achilles. Adductor covers medial ankle. 0.25 ropiv won't do much either.

The popliteal should work well, use 30ml 0.5 bupiv. Bupiv works better and lasts longer

 

[abolt18]

Hi. I've been having varied success and just plain straight-up weirdness with these blocks for Achilles repairs.

Had two the other day, both easy blocks, saw the LA spread around the sciatic (I'm injecting above the bifurcation), plus good spread in the adductor canal. 20 mL of 0.5% Ropi for the popliteal, with 10 mL of 0.25% Ropi for the adductor canal. After blocks, kept patients on 4% Et Desflurane. 50 ug fentanyl and nothing else during case. Zero change in vital signs throughout the entire hour-long procedure. Get to PACU and both patients are in pain! One complaining of heel pain, and the other just saying "I'm definitely not numb." Both were satisfied with 0.4 mg Dilaudid, and they were on their way. Still, how are they having pain?! Again, zero signs that the blocks weren't working during the operation, and only at 4% Desflurane. Healthy males for both. Grrrr...

Maybe try doing your sciatic right at the split? Putting the needle RIGHT in the crotch of the nerves. Where there's 2 distinct nerves but they're still connected. You can then scan down the leg and see local spreading around both nerves separately. That's how I like to do them.

 

[Hoya11]

Hi. I've been having varied success and just plain straight-up weirdness with these blocks for Achilles repairs.

Had two the other day, both easy blocks, saw the LA spread around the sciatic (I'm injecting above the bifurcation), plus good spread in the adductor canal. 20 mL of 0.5% Ropi for the popliteal, with 10 mL of 0.25% Ropi for the adductor canal. After blocks, kept patients on 4% Et Desflurane. 50 ug fentanyl and nothing else during case. Zero change in vital signs throughout the entire hour-long procedure. Get to PACU and both patients are in pain! One complaining of heel pain, and the other just saying "I'm definitely not numb." Both were satisfied with 0.4 mg Dilaudid, and they were on their way. Still, how are they having pain?! Again, zero signs that the blocks weren't working during the operation, and only at 4% Desflurane. Healthy males for both. Grrrr...

well could they wiggle their toes?

if they wiggle the toes you know the issue is the POP block failure

if its just vague heel pain and they can't wiggle their toes then you know its the adductor block failure/inadequacy

the 10cc for saphenous is very low volume i usually do at least 20, but for achilles i rarely do it at all unless surgeon is known to struggle and take forever and generate medial sided pain - which some do.

for popliteal try a different approach: block the nerves individually, not above the bifurcation, but just below it. this may mean you need a little more volume so maybe try 30cc 0.375%

you see the nerves coming together and they are almost touching but still separate

then come in and put local around them both individually, all around not just in one spot, so they are both floating in a circular pool of local.

that block is going to work.. i have found that the sciatic sheath is thick and sometimes hard to penetrate above the bifurcation in some patients. for knees (posterior knee pain), i will go above the bifurcation and typically get a motor and sensory block, but sometimes just sensory, and rarely an incomplete block with some breakthrough nociception despite the nerve looking completely circumscribed in local - and i attribute it to the thick sheath.

hope this helps let us know

 

[Arch Guillotti]

Never done an adductor for achilles repair.

 

[vector2]

Either bad local or bad block. Common reason for sciatic block failure above the bifurcation (or partial/inadequate block) is that you didn't put local inside the sheath (subparaneural).

 

[Simba1711]

Yes agree with what the others said about the popliteal. You can also scan more proximal after injecting to make sure the individual nerves are surrounded in local. For the acb I don’t see the nerve but I know I’m in the adductor canal when the femoral artery moves down during injection. You will be dangerously close to artery during injection so very important to aspirate.

 

[rick roller pump]

Duke channel is best IMO. I do as the video says and put local in the sheath.

Also for adductor, make sure to do it high up enough to get nerve to vastus medialis

 

[gunnershow]

Duke channel is best IMO. I do as the video says and put local in the sheath.

Also for adductor, make sure to do it high up enough to get nerve to vastus medialis

you don't need nvm for an achilles. you don't even need saphenous for an achilles

 

[sevo00]

Why would you do an adductor for an Achilles? Adductor covers the saphenous which doesn’t provide coverage to the posterior foot nor leg?

 

[dannyboy1]

Why would you do an adductor for an Achilles? Adductor covers the saphenous which doesn’t provide coverage to the posterior foot nor leg?

Agreed. Our podiatrists always ask for them. I always tell them that at the ankle level the adductor only covers skin at the medial side. Just put some local in the medial incision.

 

[DocVapor]

Duke channel is best IMO. I do as the video says and put local in the sheath.

Also for adductor, make sure to do it high up enough to get nerve to vastus medialis

As an aside, every time I watch one of these videos with excellent ultrasound anatomy (nerves <1cm deep like in this video) and they call it "typical" my eyes go into a near-unstoppable rolling seizure.

Anyone have any video series out there for nerve blocks on the Biscuit-And-Gravy diet patient?

 

[Simba1711]

Antidotally I find it easier for obese patients. Getting them in position is really difficult tho. For the muscular young patients it’s hard to differentiate the nerves from the other tissue. Tilting the probe toward the knee usually helps but even then it’s difficult sometimes.

 

[woopedazz]

Agree with everyone else. Local at the level of bifurcation, inside the sheath, scan down halfway through injecting to ensure its bathing both nerves. If only one --> put the other half of the local around the missed nerve. Efficient and good blocks.

 

[GassYous]

Antidotally I find it easier for obese patients. Getting them in position is really difficult tho. For the muscular young patients it’s hard to differentiate the nerves from the other tissue. Tilting the probe toward the knee usually helps but even then it’s difficult sometimes.

Do it prone

 

[sevo00]

Do it prone

Agree. That’s how I do all mine. Makes it so much easier

 

[Simba1711]

I just do it supine. Takes too long to get some patients to flip over in position. I can also do the adductor canal if needed without changing position.

 

[Arch Guillotti]

I just do it supine. Takes too long to get some patients to flip over in position. I can also do the adductor canal if needed without changing position.

yeah it seems like half the time they can't even move around in bed

 

[UscGhost]

I just do it supine. Takes too long to get some patients to flip over in position. I can also do the adductor canal if needed without changing position.

Same here.

Cables and IVs get tangled, etc.

Grab 4 blankets and prop them up and get started

 

[sevo00]

Id rather not get an arm workout in by pushing up on the ultrasound probe just to get a good view. Why work hard when patient positioning can make it so much easier, surgeons seem to understand this concept better than us

 

[gunnershow]

Id rather not get an arm workout in by pushing up on the ultrasound probe just to get a good view. Why work hard when patient positioning can make it so much easier, surgeons seem to understand this concept better than us

Because it's far more work to have to flip them prone. Most people you do a pop-saph on are ankle fractures who aren't really going to be able to flip for you anyway.

 

[Anestheezee]

I tell patient to bend their knee so their foot is resting on the table about halfway up the calf compared to the other foot. Sometimes requires an assistant to support the foot at the ankle to stabilize and perform a slight internal rotation of the knee (prevent it from sagging outward). I pass the probe through the hole in their leg with one hand. No need for sterility of probe or probe hand bc needle insertion site is far away from probe placement.

Adductor canal block completely unnecessary for these cases and in fact prevents you from devoting the full allowance of LA to the sciatic block, esp on thinner patients.

My sauce is 30mL 0.5% bupi in 1:200k PF epi + 0.2 mg/mL PF dexamethasone +/- 1mcg/kg dexmedetomodine. Sets up very quickly (addition of decadron makes it maybe 15 mins to insensate). I quote pts 20-24h of duration but can often go much longer with pop blocks. I drop the epi for diabetics and vasculopaths. I drop the precedex or but it back if concern that the chance that slight hypotension would prevent discharge home from pacu.

On approach to nerve, get needle right up next to the sheath and advanced verrrry slowly. You want to see tenting of the sheath from the needle pressing on the nerve then FEEL a pop and SEE the rebound of the tissue. No more certain way to be within the subparaneural space.

I do one approach under the nerves and then an approach on top of the nerves to endure a full donut of local around them. Check up and down the leg to make sure your spread is staying within the sheath.

100% of the time it works 100% of the time.

 

[Maz777]

Stop doing adductors for Achilles. Complete waste of local if doing GA.

It doesn’t matter if you do a post-bifurcation block, pre-bifurcation, subparaneural, subepimyseal, etc. Identify both components with 100% certainty and get circumferential spread around both. Subparaneural only makes a difference if you are doing catheters.

I do sciatics lateral facing me. Prone is annoying to position and doesn’t buy you any better working conditions. Supine is akin to a surgeon doing a prone umbilical hernia repair. No effing thanks. Don’t make your life hard.

 

[Test Boy]

I never had to do an adductor canals for any Achilles repair. Popliteal should cover everything. Popliteal is easily done either lateral position or supine (but need a fairly large ramp to elevate the leg). Agree that prone position doesn’t add anything and it’s just more headache.

 

[GassYous]

I actually also do it supine but I elevate the foot with a few rolled up blankets. But if you're having trouble, getting the probe in position and keeping it steady is easier in prone position.

 

[cytocide]

Adductor canal barely makes sense for a knee. The sciatic should cover it - not clear why it didn’t work for you.

 

[Simba1711]

The rare times I do prone for popliteal I make sure to mark both the front and back of knee. Have heard of a few situations in which after the patient is flipped wrong side is blocked when switching from pop to acb.

 

[nimbus]

The rare times I do prone for popliteal I make sure to mark both the front and back of knee. Have heard of a few situations in which after the patient is flipped wrong side is blocked when switching from pop to acb.

Usually but not always the leg with the big splint on it

 

[FiO2@21]

I just do it supine. Takes too long to get some patients to flip over in position. I can also do the adductor canal if needed without changing position.

Same here.

Cables and IVs get tangled, etc.

Grab 4 blankets and prop them up and get started

Id rather not get an arm workout in by pushing up on the ultrasound probe just to get a good view. Why work hard when patient positioning can make it so much easier, surgeons seem to understand this concept better than us

Because it's far more work to have to flip them prone. Most people you do a pop-saph on are ankle fractures who aren't really going to be able to flip for you anyway.

Just do it after flipping prone after induction. The block seems to set up in time and I have some extra prop to paint over the onset speed if needed. Paralyzed anyway, they won't move with incision.

 

[nimbus]

Just do it after flipping prone after induction. The block seems to set up in time and I have some extra prop to paint over the onset speed if needed. Paralyzed anyway, they won't move with incision.

You do popliteal sciatics asleep? Are you peds?

 

[Maz777]

Just do it after flipping prone after induction. The block seems to set up in time and I have some extra prop to paint over the onset speed if needed. Paralyzed anyway, they won't move with incision.

That deviates highly from the standard of care. No thanks.

 

[GassYous]

I usually don't do blocks asleep but I don't think it's a deviation from standard of care. Most of my failed blocks are from when overly anxious/chronic pain patients are screaming from the needle stick and make me concerned that I misplaced the needle so I don't go in deep enough.

I think the popliteal block is one of the more forgiving blocks and less likely to have permanent nerve injury.

 

[gunnershow]

I usually don't do blocks asleep but I don't think it's a deviation from standard of care. Most of my failed blocks are from when overly anxious/chronic pain patients are screaming from the needle stick and make me concerned that I misplaced the needle so I don't go in deep enough.

I think the popliteal block is one of the more forgiving blocks and less likely to have permanent nerve injury.

It's probably one of the highest risk blocks for nerve injury lol

 

[Simba1711]

I do my popliteal blocks , adductor canal blocks , and ipacks under general anesthesia. I do my brachial plexus blocks under conscious sedation.

I don’t think there is strong evidence showing that there is higher risk of nerve injury for blocks performed under ga compared to sedation.

 

[UscGhost]

I do my popliteal blocks , adductor canal blocks , and ipacks under general anesthesia. I do my brachial plexus blocks under conscious sedation.

I don’t think there is strong evidence showing that there is higher risk of nerve injury for blocks performed under ga compared to sedation.

The theory is that a intraneural needle placement is more easily detected in an awake patient prior to subsequent injection. Or at least that is the traditional teaching.

I am not necessarily convinced of that, as nerve pain will cause the patient to jump even under GA.

However, if the surgeon or tourniquet causes sciatic nerve injury, then it's one thing that may help you to defend yourself if you can show that the patient was awake and you didn't do an intraneural injection.

I don't necessarily think it's up to the level of standard of care, but it's definitely the more traditional teaching. So I wouldn't do it under GA routinely unless there is a good documented reason, or sporadic

 

[repititionition]

it doesn’t matter what you think. it only marginally matters what’s true.

what matters is what the plaintiffs attorney can find an expert witness to say. And they will have an easy time finding an expert witness who will testify that blocks under GA carry inherently higher risk of occult nerve injury.

 

[teacher2md]

it doesn’t matter what you think. it only marginally matters what’s true.

what matters is what the plaintiffs attorney can find an expert witness to say. And they will have an easy time finding an expert witness who will testify that blocks under GA carry inherently higher risk of occult nerve injury.

That’s the sad truth

 

[Maz777]

I usually don't do blocks asleep but I don't think it's a deviation from standard of care. Most of my failed blocks are from when overly anxious/chronic pain patients are screaming from the needle stick and make me concerned that I misplaced the needle so I don't go in deep enough.

I think the popliteal block is one of the more forgiving blocks and less likely to have permanent nerve injury.

Blocks are completely elective. If a patient can't tolerate an awake block with mild sedation, you probably shouldn't be blocking that person to begin with. Plenty of non-interventional ways to achieve analgesia. Take the needle out and call it a day if they can't tolerate a simple poke. This isn't the pediatric population.

 

[cytocide]

Blocks are completely elective. If a patient can't tolerate an awake block with mild sedation, you probably shouldn't be blocking that person to begin with. Plenty of non-interventional ways to achieve analgesia. Take the needle out and call it a day if they can't tolerate a simple poke. This isn't the pediatric population.

Even adductor canal? What’s the worst that can happen? It works.

 

[Maz777]

Even adductor canal? What’s the worst that can happen? It works.

I've heard about a number of saphenous nerve injuries after orthopedic surgery. It's lovely when you do a block at the exact site of their 2-3 hr tourniquet, ain't it?

 

[pgg]

The rare times I do prone for popliteal I make sure to mark both the front and back of knee. Have heard of a few situations in which after the patient is flipped wrong side is blocked when switching from pop to acb.

Patients should be marked before blocks and that marking should be visible before the block, and specifically verbally noted during the timeout. I know a lot of people are sloppy about not doing timeouts before blocks, but those people are wrong.

I remember an M&M when I was a resident and this happened. The usual care at my program then was to sedate the hell out of block patients, so the patient wasn't even aware enough to know the wrong side was getting done. Midazolam, fentanyl, +/- some ketamine. Kind of weird to look back on it now. I don't do a huge number of blocks these days, but I can't remember the last time I gave a patient any sedation for one.

Fortunately, in the grand scheme of things blocking the wrong limb is more embarrassing than injurious.

 

[pgg]

You do popliteal sciatics asleep? Are you peds?

Asleep ultrasound guided blocks are absolutely safe - probably safer than awake blocks since the the patients never move and the general anesthetic raises the seizure threshold.

I and other military anesthesiologists did many many many asleep peripheral single shot blocks, perineural catheters, and epidurals in Iraq and Afghanistan and nerve injuries just weren't happening. Of course, immunity to lawsuits (Feres Doctrine) made the legal risk a non-issue, else you couldn't have talked me into doing it.

Admittedly, the risk/benefit profile was skewed too - it's probably not right to compare those patients with some of the horrendous extremity injuries they had with some random person who fractured an ankle stepping off a curb. The expected postop pain levels and opioid requirements aren't comparable so we were motivated to push the envelope of regional anesthesia. (Also, does it really matter if you bag the popliteal nerve in a person who doesn't have a foot any more?)

Even though I'm convinced asleep blocks are perfectly safe, I don't do them now and I wouldn't consider it. It's maybe an overstatement to say they're outside the standard of care, but it sure would add a burden to the defense of a malpractice suit. There's just no upside to doing it.

 

[nimbus]

Asleep ultrasound guided blocks are absolutely safe - probably safer than awake blocks since the the patients never move and the general anesthetic raises the seizure threshold.

I and other military anesthesiologists did many many many asleep peripheral single shot blocks, perineural catheters, and epidurals in Iraq and Afghanistan and nerve injuries just weren't happening. Of course, immunity to lawsuits (Feres Doctrine) made the legal risk a non-issue, else you couldn't have talked me into doing it.

Admittedly, the risk/benefit profile was skewed too - it's probably not right to compare those patients with some of the horrendous extremity injuries they had with some random person who fractured an ankle stepping off a curb. The expected postop pain levels and opioid requirements aren't comparable so we were motivated to push the envelope of regional anesthesia. (Also, does it really matter if you bag the popliteal nerve in a person who doesn't have a foot any more?)

Even though I'm convinced asleep blocks are perfectly safe, I don't do them now and I wouldn't consider it. It's maybe an overstatement to say they're outside the standard of care, but it sure would add a burden to the defense of a malpractice suit. There's just no upside to doing it.

I also believe they are safe but they’re not yet accepted and can cause medicolegal issues if there’s a postop nerve injury.

 

[nimbus]

The theory is that a intraneural needle placement is more easily detected in an awake patient prior to subsequent injection. Or at least that is the traditional teaching.

I am not necessarily convinced of that, as nerve pain will cause the patient to jump even under GA.

However, if the surgeon or tourniquet causes sciatic nerve injury, then it's one thing that may help you to defend yourself if you can show that the patient was awake and you didn't do an intraneural injection.

I don't necessarily think it's up to the level of standard of care, but it's definitely the more traditional teaching. So I wouldn't do it under GA routinely unless there is a good documented reason, or sporadic

I probably did a lot of intraneural injections doing nerve stimulator blocks before ultrasound became popular. No issues that I know of.

 

[nimbus]

I do my popliteal blocks , adductor canal blocks , and ipacks under general anesthesia. I do my brachial plexus blocks under conscious sedation.

I don’t think there is strong evidence showing that there is higher risk of nerve injury for blocks performed under ga compared to sedation.

You’re right. The awake only blocks is not supported by evidence. In fact the pediatric literature has shown it is safe. People were doing a lot of asleep blocks until the early 2000s. The practice changed based on a series of 4 cases. It would be difficult to duplicate the complications using modern ultrasound guided technique.

Permanent Loss of Cervical Spinal Cord Function Associated with Interscalene Block Performed under General Anesthesia

PERFORMING an interscalene block (ISB) during general anesthesia (GA) for postoperative shoulder surgery analgesia is a common procedure. Although epidural, 1–3subarachnoid, 4–6and motor nerve root 7injections have been reported during the performance of ISB, there have been no cases reported in...

pubs.asahq.org

 

[abolt18]

Did an asleep adductor/sciatic on a 40 or 50 something year old developmentally delayed adult guy living in an assisted living facility a couple weeks ago for his Tib/Fib ORIF. It was quite lovely doing it while he was under GA. He would not have sat still for the block.

 

[FiO2@21]

That deviates highly from the standard of care. No thanks.

That is not true in my community. There is not significant evidence to support insisting on awake blocks. Barring patient preference I do blocks depending on the accepted workflow of the facility. Some places have block bays where they get awake blocks. Others get it under GA. Thoughtful needling under ultrasound is safe and supported by pediatric anesthesia literature.

 

[Maz777]

That is not true in my community. There is not significant evidence to support insisting on awake blocks. Barring patient preference I do blocks depending on the accepted workflow of the facility. Some places have block bays where they get awake blocks. Others get it under GA. Thoughtful needling under ultrasound is safe and supported by pediatric anesthesia literature.

You should really hope you don't get blamed for a nerve injury. Lawyers will have a field day with expert witnesses lining up at the door.

 

[Dr. Rude]

You’re right. The awake only blocks is not supported by evidence. In fact the pediatric literature has shown it is safe. People were doing a lot of asleep blocks until the early 2000s. The practice changed based on a series of 4 cases. It would be difficult to duplicate the complications using modern ultrasound guided technique.

Permanent Loss of Cervical Spinal Cord Function Associated with Interscalene Block Performed under General Anesthesia

PERFORMING an interscalene block (ISB) during general anesthesia (GA) for postoperative shoulder surgery analgesia is a common procedure. Although epidural, 1–3subarachnoid, 4–6and motor nerve root 7injections have been reported during the performance of ISB, there have been no cases reported in...

pubs.asahq.org

There was an editorial specifically condemning the practice in Anesthesiology a long while ago. (Pre ultrasound).
It would be nice if they would revisit the topic and put their nickel down one way or another.