Femoral nerve block and quadriceps weakness

[Gas]

Hi all, question for the regional experts. Some of our orthopods have said they do not want femoral nerve blocks for their TKR or ACL patients anymore, citing quadriceps weakness. I am not aware of femoral blocks contributing to quadriceps weakness, but I was wondering what others out there are doing.

At our small community hospital, we do a single shot, 20-30cc 0.25% marcaine with epi, half with U/S, half without. Some of our guys refuse to learn it. No catheters.

I haven't found much in the literature that says femoral blocks should be witheld for this reason, but some do say the block can be associated with quad weakness, but it seems like it would be caused by the surgery itself rather than the block. But better quad strength does lead to better surgical outcomes.

The orthopods cannot find the studies, nor do they know anything about what dose/concentration local, single shot vs. catheter, ultrasound vs. non-ultrasound. Go figure.

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[BLADEMDA]

Femoral nerve block (FNB) is considered the gold standard for total knee arthroplasty (TKA) postoperative analgesia. However, there is a measurable quadriceps weakness in one third of patients with FNB after TKA {1}. More concerning, a retrospective review of TKA patients after single injection FNB (n=729) versus no block (N=241) demonstrated an increased risk of fall of 1.6 versus 0.4% {2}. Furthermore, quadriceps dysfunction may persist beyond two days after cessation of FNB as a result of femoral nerve palsy based on a review by Brull et al. {3}. Adductor canal block (ACB) has been advocated as an alternative with less risk of motor weakness.

The authors of this current double blind placebo-controlled randomized crossover study compared ACB with FNB using maximum voluntary isometric contraction for quadriceps and adductor muscles, along with three standardized functional tests as outcome measures. Femoral nerve block and adductor canal injections were performed with either 30ml 0.1% ropivacaine or isotonic saline. Quadriceps strength was significantly reduced when comparing ACB with placebo, FNB with placebo, and FNB with ACB. The mean reduction from baseline was 8% with ACB (presumed to be related to vastus medialis or side-to-side difference) and 49% with FNB. Performance in all mobilization tests was reduced after FNB compared with ACB.

We now have objective evidence that ACB spares quadriceps function, possibly reducing the risk of falls and quadriceps dysfunction. Compared with placebo, the ACB significantly reduced 24-hour morphine consumption and pain scores during 45° flexion of the knee in TKA patients {4}. However, there are no studies directly comparing both ACB and FNB for TKA. Until well-designed studies show similar benefit and side effects, there should not be an immediate change in clinical practice.

We must use caution in placing blocks within the surgeon's working environment. The location of the ACB directly below the thigh tourniquet is concerning for new complications not unique to FNB. Neurotoxic local anesthetic administered within the adductor canal at the site of neuronal ischemia related to the thigh tourniquet may potentially predispose the patient to the ‘double-crush' concept and prolonged peripheral nerve injury. Trial registration: NCT01449097
References
1.
Femoral nerve block using ropivacaine 0.025%, 0.05% and 0.1%: effects on the rehabilitation programme following total knee arthroplasty: a pilot study.
Paauwe JJ, Thomassen BJ, Weterings J, van Rossum E, Ausems ME. Anaesthesia 2008 Sep; 63(9):948-53
PMID: 18540926 DOI: 10.1111/j.1365-2044.2008.05538.x
2.
Complications of femoral nerve block for total knee arthroplasty.
Sharma S, Iorio R, Specht LM, Davies-Lepie S, Healy WL. Clin Orthop Relat Res 2010 Jan; 468(1):135-40
PMID: 19680735 DOI: 10.1007/s11999-009-1025-1
3.
Neurological complications after regional anesthesia: contemporary estimates of risk.
Brull R, McCartney CJ, Chan VW, El-Beheiry H. Anesth Analg 2007 Apr; 104(4):965-74
PMID: 17377115 DOI: 10.1213/01.ane.0000258740.17193.ec
4.
Effects of adductor-canal-blockade on pain and ambulation after total knee arthroplasty: a randomized study.
Jenstrup MT, Jæger P, Lund J, Fomsgaard JS, Bache S, Mathiesen O, Larsen TK, Dahl JB. Acta Anaesthesiol Scand 2012 Mar; 56(3):357-64
PMID: 22221014 DOI: 10.1111/j.1399-6576.2011.02621.

 

[BLADEMDA]

A1123
October 15, 2012
1:00:00 PM - 4:00:00 PM
Room Hall C-Area L
Adductor Canal Block Versus Femoral Nerve Block for Total Knee Arthroplasty
David H. Kim, M.D., Yi Lin, M.D.,Ph.D., Jacques Yadeau, M.D.,Ph.D., Enrique Goytizolo, M.D., Richard Kahn, M.D., Asha Manohar, M.D., Minda Patt, M.D., Dorothy Marcello, B.S.
Hospital for Special Surgery, New York, New York, United States
2012 ASA Abstract

Background: Optimal pain relief is essential for functional recovery, especially in patients who undergo total knee arthroplasty. Several studies have noted that femoral nerve blocks (FNB) provide superior pain control and shortened hospital stay, in comparison with epidural or intravenous PCA alone.1-2 However, in recent years, studies have reported a small (2% incidence), but significant risk of falls after prolonged motor blockade from FNB's.3

An anatomical study of the adductor canal (AC) have demonstrated that the resulting sensory changes are not limited to the distribution of the saphenous nerve.4 They noted that medial, anterior, and lateral aspects of the knee showed sensory loss extending from the superior pole of the patella to the proximal tibia, without any noticeable motor effect in the quadriceps muscles. The AC may serve as a conduit for more than just the saphenous nerve, possibly including the vastus medialis nerve, medial femoral cutaneous nerve, articular branches from the obturator nerve, as well as the medial retinacular nerve.5-7

The question our study attempts to answer is: "Does the Adductor Canal Block(ACB) provide adequate analgesia while sparing significant motor weakness?"

Methods: This was a prospective double-blinded randomized controlled trial evaluating either a FNB or ACB's effect on quadricep strength and analgesia after total knee arthroplasty. A dynamometer was used to assess quadriceps strength. Both operative and nonoperative legs were assessed preoperatively, and 6-8 hours, 24 hours and 48 hours post-anesthesia administration. A pinprick sensory exam was also performed to confirm successful blockade.

Results: 38 patients received FNB, 41 patients received SNB. While there was no significant difference in dynamometer readings prior to surgery, patients with a FNB had significantly lower dynamometer readings 6-8 hour post-anesthesia vs. the ACB treatment group. For postoperative days 1 and 2, there was no statistical difference in dynamometer results between the two groups. Analysis of NRS pain scores revealed no significant difference throughout the hospital course.

Comments: This comparison study shows that while there was no difference in pain control in the postoperative care unit, quadriceps strength was more spared with use of the adductor canal block.

References

1. Anesthesiology. 1999;91:8-15.

2. Anesth Analg. 1998;87:88-92.

3. The Knee. 2009;16:98-100.

4. RAPM. 2009;32(4):369-70.

5. RAPM. 2009;34🙁5):486-89.

6. Knee Surg Sports Traumatol Arthrosc. 2008;16:855-858.

7. RAPM. 2009;34(6):578-80.

Table 1. Mean Dynamometer Readings Over Time

*P-Values were obtained from .

Table 2. NRS- Pain Scores Over Times

 

[sevoflurane]

I am not aware of femoral blocks contributing to quadriceps weakness, ....

NO doubt it contributes to quad weakness.
If you are doing these blocks, you need to know the side effects. 😳
100% of patients receiving a fem. nerve block will have quad weakness.

Adductor canal is pretty darn good, but it is not anywhere close to a fem. nerve block...although with considerable less weakness (if any).

Remeber that as soon as you cross the inguinal ligament, the fem. nerve has already branched into many small tributaries. Therefore, the adductor canal is not a silver bullet.

 

[sevoflurane]

 

[BLADEMDA]

NO doubt it contributes to quad weakness.
If you are doing these blocks, you need to know the side effects. 😳
100% of patients receiving a fem. nerve block will have quad weakness.

Adductor canal is pretty darn good, but it is not anywhere close to a fem. nerve block...although with considerable less weakness (if any).

Remeber that as soon as you cross the inguinal ligament, the fem. nerve has already branched into many small tributaries. Therefore, the adductor canal is not a silver bullet.

Correct. No free lunch here. FEMORAL blocks are much better in terms of pain control but have quadriceps weakness as a side effect.

Adductor Canal block is decent for post pain control but inferior to a Femoral block. Minimal quadriceps weakness.

 

[Planktonmd]

A successful Femoral nerve block ALWAYS causes quadriceps weakness.
The duration and intensity of that weakness is proportional to the concentration of your local anesthetic, the volume, and the kind of local anesthetic used.
Many people think that Ropivacaine causes less weakness than Bupivacaine although it appears it's more a question of potency.
On my single shot Femoral blocks I use 20 cc Bupivacaine 0.25% and this seems to produce good analgesia and very limited Quadriceps weakness.
Still, some of our surgeons have elected no nerve blocks and instead they started using a peri-articular infiltration of Ropivacaine+ Toradol + Morphine.
I used to be skeptical about this strange cocktail but it does work!
And these patients do well without nerve blocks!

 

[fakin' the funk]

I haven't found much in the literature that says femoral blocks should be witheld for this reason, but some do say the block can be associated with quad weakness, but it seems like it would be caused by the surgery itself rather than the block. But better quad strength does lead to better surgical outcomes.

The orthopods cannot find the studies, nor do they know anything about what dose/concentration local, single shot vs. catheter, ultrasound vs. non-ultrasound. Go figure.

😱

 

[excalibur]

OK, I just did one today.

Adductor canal block and sciatic nerve block for TKA.

Pt did well. He required some supplemental fentany, and I gave some IV acetaminophen, but overall did well. No narcs needed in PACU.

30 mL of Bupi 0.5% with 4 mg of PF Dexamethasone used in this nondiabetic pt.

21 mL for sciatic and 9 mL for adductor canal block.

I visualized fem art under sartorius around mid thigh with US. I could see the saphenous nerve lateral to the artery. I actually also used a nerve stimulator at 1.00 MHz to elicit a paresthesia in the medial ankle.

My question: Are you guys still adding the sciatic for your TKA's??

In doing a quick literature search it appears that there is evidence that pt's don't do as well with femoral block alone as compared to fem + sci block, which would lead me to believe that pts would do better with adductor canal block + sciatic as compared to adductor canal block alone.

Do orthopods feel sciatic block causes problems like potential foot drop? weakness with falls? masking common peroneal pain compression pain?

 

[climbingak]

Biggest worry with the addition of the sciatic is the surgeon not sleeping as well that night. Most of my surgeons want to see the common peroneal working after surgery and then they let me block it if needed. Its been good because more than half of my patients haven't needed it. Those that feel they do, get it in the PACU. I do fem caths up front.

 

[Pooh & Annie]

NO doubt it contributes to quad weakness.
If you are doing these blocks, you need to know the side effects. 😳
100% of patients receiving a fem. nerve block will have quad weakness.

Adductor canal is pretty darn good, but it is not anywhere close to a fem. nerve block...although with considerable less weakness (if any).

Remeber that as soon as you cross the inguinal ligament, the fem. nerve has already branched into many small tributaries. Therefore, the adductor canal is not a silver bullet.

We do ACs as our standard for TKRs. I don't agree that it isn't close to the same for pain relief. Even though you may miss some of the proximal femoral branches, it works incredibly well. Keep an eye out for an upcoming study in RAPM out of vieginia mason.

 

[reanimatore]

We do ACs as our standard for TKRs. I don't agree that it isn't close to the same for pain relief. Even though you may miss some of the proximal femoral branches, it works incredibly well. Keep an eye out for an upcoming study in RAPM out of vieginia mason.

I agree.

In my experience the analgesia provided by an ACB for TKA seems pretty darn similar to that of a femoral block. Several surgeons that I've worked with now specifically request ACB block, and I wouldn't be surprised if it supplants femoral blockade in many settings/institutions down the road. The ability to participate in PT on POD1 is quite impressive with ACB, and many will consider this worth any small decrease in analgesia (if there is one) when compared to FNB. Head to head data is coming down the pike.

 

[dhb]

I might give ACB a try but my main problem is that i have a much higher percentage of patient complain of sciatic pain after TKA or ACL surgery than the reported 20% i would almost say it's the other way around 80% sciatic pain...

 

[Pooh & Annie]

I might give ACB a try but my main problem is that i have a much higher percentage of patient complain of sciatic pain after TKA or ACL surgery than the reported 20% i would almost say it's the other way around 80% sciatic pain...

That's high. Surgical technique issue? Is it true with all of your surgeons?

 

[excalibur]

So are you gurus who do ACB adding sciatic block?

 

[BLADEMDA]

Adductor canal block and selective tibial. The sweet spot for postop pain relief after total knee replacement.

We have been using selective tibial for the past 150 total knees. Only 3 patients required a common peroneal nerve block in pacu.

FYI, studies suggest that 15 mls of local completely fills the adductor canal. So I suggest 12-15 mls of volume for the best adductor canal block possible. Don't forget to place local
Anterior and posterior to the artery as well as local around the saphenous nerve itself

 

[sevoflurane]

The ability to participate in PT on POD1 is quite impressive with ACB... [/B]

This is the biggest draw for ACB.

I recently had a long conversation with the director of acute pain medicine in a near by orthopedic hospital (he has personally performed 5000 blocks at this site). We had a conversation about ACB and how they compare to FNB.

His perception is the same as mine: ACB are great, they indeed to provide good analgesia, but it is not the same level of analgesia/anasthesia you can achieve with a FNB.

Here is why:

1) The anatomy of the femoral nerve is very variable. Sometimes dividing extensively before traversing the inguinal ligament. There are papers and cadaver dissections on this topic in relation to surgical exposure. ie: aorto-bifem bypasses.

2) There are 2 divisions of the femoral nerve. The anetrior and posterior divisions:
Anterior division: Middle cutaneous and Medial cutaneous nerves. These branches may provide cutaneous sensation to the superior anterior aspect of the patella. They may also communicate with the infrapatellar plexus of the saphenous. We miss this with an ACB.


Posterior division: Posterior devision is what we are blocking in the adductor canal. It is mainly the saphenous nerve... but it CAN and DOES (in most cases) give branches to the patellar plexus.. which comunicates with the anterior cutaneous branches of the ANTERIOR division of the fem. nerve.

Again, the ACB is great. Tomorrow I'm putting in a AC catheter in a morbidly obese patient that had respiratory arrest from his last knee due to severe sleep apnea and intolerance to narcotics.
He will also get 2% lido FNB for the case + 2% lido/.2% rop. low sciatic single shot. Should be a narctotic free anesthetic and will hopefully get him walking around the floor on POD 0 with minimal weakness.

I'd like to see more studies out there. If we could reliably get the infra and supra patellar plexus with the ACB, it would be excellent. Unfortunately, we are not all built the same and significant anatomical variations exist.

Great topic. Can't wait to see more studies on this.

 

[sevoflurane]

FWIW, another trick we've been using is ACB + local infiltration (lateral more than medial).

This seems to work really well.

 

[periopdoc]

If you want them to have full strength for PT the next day, skip all the single shot B.S. You will never find the perfect balance that works for every patient.

Just put in a catheter, run a surgical block with lidocaine, and run a dilute bupi post-operative block for pain control. Turn it off at midnight and it will be worn off in all patients by the time PT comes in to see them. Turn it back on in the evening for a good night sleep then pull the cath the next day.

Of course the "intrarticular" injections and pain buster pumps are the bomb. I am doing a TKA right now and will use 100 mcg of fent to get her through until the block sets up. Same thing I did for her other knee last month and she was so happy that she requested me again.

- pod

 

[excalibur]

Adductor canal block and selective tibial. The sweet spot for postop pain relief after total knee replacement.

We have been using selective tibial for the past 150 total knees. Only 3 patients required a common peroneal nerve block in pacu.

FYI, studies suggest that 15 mls of local completely fills the adductor canal. So I suggest 12-15 mls of volume for the best adductor canal block possible. Don't forget to place local
Anterior and posterior to the artery as well as local around the saphenous nerve itself

Selective tibial?

Are you just using ultrasound to isolate the tibial immediately after the divide and dumping local circumferentially? 10-15 mL?

And I think Blade you said you are not using decadron for this ACB with selective tibial. Is that right?

 

[sevoflurane]

If you want them to have full strength for PT the next day, skip all the single shot B.S. You will never find the perfect balance that works for every patient.

Just put in a catheter, run a surgical block with lidocaine, and run a dilute bupi post-operative block for pain control. Turn it off at midnight and it will be worn off in all patients by the time PT comes in to see them. Turn it back on in the evening for a good night sleep then pull the cath the next day.

Of course the "intrarticular" injections and pain buster pumps are the bomb. I am doing a TKA right now and will use 100 mcg of fent to get her through until the block sets up. Same thing I did for her other knee last month and she was so happy that she requested me again.

- pod

I think you mean "periarticular". 😉

 

[dhb]

That's high. Surgical technique issue? Is it true with all of your surgeons?

Not really. Only a couple of surgeons doing knees one more than the other

 

[ASA6]

Silly question here: We have been using "mid thigh" saphenous blocks. Is this the same thing as an adductor canal block? Or are these blocks performed in different locations?

 

[psychbender]

Silly question here: We have been using "mid thigh" saphenous blocks. Is this the same thing as an adductor canal block? Or are these blocks performed in different locations?

Same block.

 

[BLADEMDA]

If you want them to have full strength for PT the next day, skip all the single shot B.S. You will never find the perfect balance that works for every patient.

Just put in a catheter, run a surgical block with lidocaine, and run a dilute bupi post-operative block for pain control. Turn it off at midnight and it will be worn off in all patients by the time PT comes in to see them. Turn it back on in the evening for a good night sleep then pull the cath the next day.

Of course the "intrarticular" injections and pain buster pumps are the bomb. I am doing a TKA right now and will use 100 mcg of fent to get her through until the block sets up. Same thing I did for her other knee last month and she was so happy that she requested me again.

- pod

I've got a magical single shot block which lasts for 72 hours and doesn't cause weakness. At least equal to your "catheter" but without the hassle. Patients love it. PM me or start a thread in the private forum

 

[BLADEMDA]

Selective tibial?

Are you just using ultrasound to isolate the tibial immediately after the divide and dumping local circumferentially? 10-15 mL?

And I think Blade you said you are not using decadron for this ACB with selective tibial. Is that right?

http://www.ncbi.nlm.nih.gov/pubmed/22543069

I'm enjoying great success with the selective tibial block. FYI, I use PF decadron (2-4 mg) with my local for Femoral blocks. This way patients sleep through the night pain free. I usually add 1 mg of decadron to my single shot tibial blocks as well.

For adductor canal blocks I prefer my special solution or 0.5 percent Bup with 4 mg decadron (15 ml)

 

[BLADEMDA]

FWIW, another trick we've been using is ACB + local infiltration (lateral more than medial).

This seems to work really well.

Agree. ACB, selective tibial plus local infiltration. Minimal weakness and patients can easily ambulate the next day. Skip the selective tibial if you prefer ambulation on POD 0

 

[Planktonmd]

I've got a magical single shot block which lasts for 72 hours and doesn't cause weakness. At least equal to your "catheter" but without the hassle. Patients love it. PM me or start a thread in the private forum

Sure... it's called intraneural injection... sometimes it lasts years 😀

 

[Mman]

I've got a magical single shot block which lasts for 72 hours and doesn't cause weakness. At least equal to your "catheter" but without the hassle. Patients love it. PM me or start a thread in the private forum

when somebody invents the magic local anesthetic that blocks pain transmission but not motor transmission our patients will all love us dearly, until then you can't reliably get 1 without the other

 

[stonemd]

Options to block sciatic component

Preop Infiltrate between femus shaft and pop artery proximal to femoral condyles
Or
Intraop let surgeon inject trans post cruciate ligament

Both should get nerves innervating post knee while avoiding sciatic/tibial/fibular nerve block

 

[sevoflurane]

http://www.nysora.com/nysora_newsletters/3380-nysora-newsletter-march-2013.html

Fun little read (scroll down past the first page).

 

[BLADEMDA]

when somebody invents the magic local anesthetic that blocks pain transmission but not motor transmission our patients will all love us dearly, until then you can't reliably get 1 without the other

You are so 2011. We have a drug which lasts for 72 hours slim. Try it. No motor weakness with good sensory block:

A: To us, that is a hypothetic question, because in Denmark, the surgeons made us abandon the FNB for most surgical procedures some time ago. But, the advantage of the ACB is that it does not hamper mobilization, with the potential to enhance rehabilitation and avoid fall episodes postoperatively. In our study in healthy volunteers we showed that all subjects could be mobilized and perform three standardized ambulation tests without gait aids with an ACB. In comparison, only half of the subjects could be mobilized after a FNB, and of those who could be mobilized, three subjects might be considered non-responders.

We have also compared the ACB with placebo, in patients following TKA, and found that the ACB enhanced mobilization, probably due to better analgesia. In contrast, ACB did not confer further benefits in patients receiving a basic analgesic regimen with paracetamol and ibuprofen after arthroscopic ACL reconstruction, probably due to low pain scores in our control group.

As we don’t use the FNB for TKA anymore, in our practice there was a need to replace/supplement LIA, which we found to be inadequate. Of course, in order to compete with the FNB, the ACB will have to provide comparable analgesia, and that is what we have looked at next.

 

[sevoflurane]

AC catheter. They are simple to do. You just have to be careful with the fem. art (9 o'clock and a little blurry) and vein (squished at 6 o'clock). The Touhy can put a big hole in that sucker. What I've been doing is hydrodissecting the saph nerve OFF of the artery and fascia... creating a space for my catheter to be placed. Works great, especially when the catheter correctly places a doughnut of LA around the nerve (multi port stiff catheter). In the attached pic, you can see the saph nerve dissected from the fascia and artery. It took about 5 minutes start to finish (with full on sterile technique).

 

[sevoflurane]

BTW, single shot ACB with exparel sounds really nice as well. We don't have it... yet.

 

[Mman]

You are so 2011. We have a drug which lasts for 72 hours slim. Try it. No motor weakness with good sensory block:

what drug do we have the selectively blocks sensory fibers for 72 hours but not motor fibers? I'm unaware of one approved for clinical use by the FDA.

I'm not sure what you are even referring to.

 

[OB1🤙]

Presumably we're tunneling these ac catheters through the sartorius. Any discomfort associated with that?

I have only done this as a single shot but I love this block. If I had exparel I'd love it even more.

 

[BLADEMDA]

BTW, single shot ACB with exparel sounds really nice as well. We don't have it... yet.

Yes. I have it and use it. 72 hours. No catheter

 

[Planktonmd]

Yes. I have it and use it. 72 hours. No catheter

You are not talking about Exparel are you?

You know that the drug has only been FDA approved for infitration and only for Hrmorrhoids and Bunions.

 

[BLADEMDA]

You are not talking about Exparel are you?

You know that the drug has only been FDA approved for infitration and only for Hrmorrhoids and Bunions.

BLADEMDA approved for TAP, SUBCOSTAL TAP, ADDUCTOR CANAL AND TPVB.

Safe and effective.

 

[Planktonmd]

BLADEMDA approved for TAP, SUBCOSTAL TAP, ADDUCTOR CANAL AND TPVB.

Safe and effective.

How do you know it's safe without any supporting data?

 

[BLADEMDA]

How do you know it's safe without any supporting data?

The data is out there. Company in the process of getting FDA approval for sensory nerve blocks. They expect approval this year or early next year

 

[fakin' the funk]

The arrogance and bombast in this thread is simply breathtaking.

 

[BLADEMDA]

The arrogance and bombast in this thread is simply breathtaking.

Exparel has been used for TAP/Subcostal TAP blocks tens of thousands of times on patients. The Company, Pacira, has a huge trial underway right now with dozens of hospitals. The sales Reps are PROMOTING the use of Exparel for Tap blocks.

Top Ten medical centers are using this drug for that block as well. There is no issue with it for sensory blocks. Motor block approval is at least 12-18 months away.

 

[Mman]

The data is out there. Company in the process of getting FDA approval for sensory nerve blocks. They expect approval this year or early next year

We all expected Suggamadex to have approval years ago as well. Stuff happens.

As for exparel, it is not selectively block sensory neurons. It's still bupivicaine. The local is the same, it's the liposomal preparation that provides the duration of action.


Just a question, though, what's the cardiac toxicity profile of such a drug? We know Bupivicaine isn't great for the myocardium. Does the exparel preparation make it even harder to treat toxicity than regular old bupivicaine?

 

[Mman]

The sales Reps are PROMOTING the use of Exparel for Tap blocks.

They better not be as I'm pretty sure that violates federal law.

 

[Arch Guillotti]

The sales Reps are PROMOTING the use of Exparel for Tap blocks.

So what? Of course they are promoting it.

 

[Ipassgas]

At one of our hospitals, our ortho guys told us to stop doing FNB due to weakness before I started. They infiltrate Exparel and love it. I can't get them interested in adductor canal blocks. 🙁

 

[sevoflurane]

Presumably we're tunneling these ac catheters through the sartorius. Any discomfort associated with that?

I have only done this as a single shot but I love this block. If I had exparel I'd love it even more.

HB. Not as bad as you'd think. Sedation then local with a small gauge spinal needle followed by an epidural 17g touhy. A lot less stimulating than a LP catheter... more like a pop catheter. Do it man. It's good stuff with little to no motor weakness. 👍

 

[sevoflurane]

At one of our hospitals, our ortho guys told us to stop doing FNB due to weakness before I started. They infiltrate Exparel and love it. I can't get them interested in adductor canal blocks. 🙁

😡

 

[reanimatore]

HB. Not as bad as you'd think. Sedation then local with a small gauge spinal needle followed by an epidural 17g touhy. A lot less stimulating than a LP catheter... more like a pop catheter. Do it man. It's good stuff with little to no motor weakness. 👍

Agreed. It's not difficult to place a catheter once you're comfortable with the block in general. I tunnel mine superiorly and medially using the touhy needle. If you place your AC block roughly at the border of the proximal and middle thirds of the thigh, once tunneled the catheter will emerge pretty close to where a femoral catheter would be (and it will definitely be clear of the surgical field).

If you are worried about traversing the body of the sartorius, you can always enter with the touhy further anteriorly and sneak below it rather than going through it (although this is not aways possible if you have an obese patient as your needle won't be long enough). But honestly, I haven't had any complaints from patients who end up with a trans-sartorial approach.