Testing adductor block

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kmurp

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When evaluating an adductor block for efficacy can one use loss of sensation to cold (alcohol wipe) or do you have to use pinprick? Some of my blocks seem to have no loss of sensation to cold but seem to work ok anyway.
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kmurp said:
When evaluating an adductor block for efficacy can one use loss of sensation to cold (alcohol wipe) or do you have to use pinprick? Some of my blocks seem to have no loss of sensation to cold but seem to work ok anyway.
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thats why FNBs are better. Way easier to assess a successful block. "Pick up your leg" "I cant" - little doubt about it. Makes you wonder how many failed ACBs youve done? Hard to tell...
 
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Best way is with an ice cube in the saphenous distribution. Alcohol wipe is too equivocal for any block in my opinion. I agree that it doesn't make you feel all warm and fuzzy the way a good motor block does though.

If you know what you are doing though, you should be able to see the sap. nerve about 90% of the time, and also see it floating in local at the end of the block. That's good enough for me. If it's one of those pts that doesn't image well (or you're one of those anesthesiologists that doesn't image well) then just do your best and don't check it!
 
I test both medial ankles with alcohol pads. There is always a difference.
 
Planktonmd said:
I think about 50% of AC blocks effects are mainly placebo affecting both the patient and the anesthesiologist.
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Pretty strong placebo when you chop someone's knee off.
I would say 100% of people that don't see an effect from TAPs ACBs etc are not doing them right.
 
dhb said:
Pretty strong placebo when you chop someone's knee off.
I would say 100% of people that don't see an effect from TAPs ACBs etc are not doing them right.
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Placebo can be very strong, don't under estimate the power of faith! 😉

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3626115/

Concluding remarks
In summary, the available scientific evidence indicates that placebo analgesic responses are mediated by psychoneurobiological mechanisms and molecular targets and that these effects substantially contribute to the overall effectiveness of analgesic treatments. Recent advances in the field have paved the way for how neuropsychological, genetic and brain-related variables may predict individual differences in placebo responsiveness. Further insights into the mechanisms of placebo analgesia, its modulation of analgesic drug pharmacodynamics, and importantly, its predictability is urgently needed to guide future translational research and improve the methodology of clinical trials and clinical practice
 
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Hoya11 said:
thats why FNBs are better. Way easier to assess a successful block. "Pick up your leg" "I cant" - little doubt about it. Makes you wonder how many failed ACBs youve done? Hard to tell...
Click to expand...
I agree it probably has better coverage due to the adductor canal missing some of the perforaters. We've been doing them mostly for knees where the ortho wants them up and walking right after, I'd say 95% are super comfortable in the pacu. If continuous adductor, even better.
 
They
OTCAwesome said:
I agree it probably has better coverage due to the adductor canal missing some of the perforaters. We've been doing them mostly for knees where the ortho wants them up and walking right after, I'd say 95% are super comfortable in the pacu. If continuous adductor, even better.
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They better be super f'n comfy in PACU. They just left the OR. I wouldn't expect them to be uncomfortable for hours even if they didn't have a block.
 
Noyac said:
They

They better be super f'n comfy in PACU. They just left the OR. I wouldn't expect them to be uncomfortable for hours even if they didn't have a block.
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I'm at a small academic center, you'd be surprised how many times I get called for patients with inadequate pain control in the pacu. Our call people see inpatient post ops the next morning, most with adductor canals are doing well, especially if we popped in a continuous.
 
OTCAwesome said:
I'm at a small academic center, you'd be surprised how many times I get called for patients with inadequate pain control in the pacu. Our call people see inpatient post ops the next morning, most with adductor canals are doing well, especially if we popped in a continuous.
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Probably the ones with continuous eventually get the local anesthetic to migrate cephalad and the rest of the femoral nerve gets blocked!
 
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You can check in the saphenous distribution above medial malleolus. We are doing a study on this particular block and at 15 to 20 minutes pretty much everyone has a change to pin prick. Almost none of the blocks fail.

That said I've done about a million of these I feel like now... so when it isnt specifically for a study I don't check it. It's gonna work if done properly (deep to sartorius, anterior to SFA between vastus medialis and adductor).

Very reliable block. No need to destroy quad function and limit PT by doing a femoral.

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OTCAwesome said:
I'm at a small academic center, you'd be surprised how many times I get called for patients with inadequate pain control in the pacu. Our call people see inpatient post ops the next morning, most with adductor canals are doing well, especially if we popped in a continuous.
Click to expand...

I'm using exparel and patients are comfortable for 48 hours. Adductor canal and I packs combined with LIA.
 
floridaboy18 said:
You can check in the saphenous distribution above medial malleolus. We are doing a study on this particular block and at 15 to 20 minutes pretty much everyone has a change to pin prick. Almost none of the blocks fail.

That said I've done about a million of these I feel like now... so when it isnt specifically for a study I don't check it. It's gonna work if done properly (deep to sartorius, anterior to SFA between vastus medialis and adductor).

Very reliable block. No need to destroy quad function and limit PT by doing a femoral.

Sent from my SM-N910V using Tapatalk
Click to expand...


http://www.wakehealth.edu/uploadedF...ents/Issues_2016/wfjsm2016v2i1p73 Henshaw.pdf

I thought you would enjoy the article. Anyway, I usually try to block the saphenous nerve as well as the nerve to the vastus medialis. I place local on both sides of the artery (semi lunar over the artery). The results are very good when combined with ipack and LIA.
 
BLADEMDA said:
http://www.wakehealth.edu/uploadedF...ents/Issues_2016/wfjsm2016v2i1p73 Henshaw.pdf

I thought you would enjoy the article. Anyway, I usually try to block the saphenous nerve as well as the nerve to the vastus medialis. I place local on both sides of the artery (semi lunar over the artery). The results are very good when combined with ipack and LIA.
Click to expand...
It is a good article, actually written by two of my mentors and the group I am joining next year ;-)

We haven't ventured into I Pack blocks yet, though. We normally do a single shot sciatic, adductor canal catheter, and spinal for TKAs. Take adductor catheter out on post op day 2.

What do you feel like you are covering with the i Pack block that is not covered by the above approach? Or is it an attempt to get same analgesic coverage without sacrificing posterior flexors (i.e. hamstrings)?

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BLADEMDA said:
http://www.wakehealth.edu/uploadedF...ents/Issues_2016/wfjsm2016v2i1p73 Henshaw.pdf

I thought you would enjoy the article. Anyway, I usually try to block the saphenous nerve as well as the nerve to the vastus medialis. I place local on both sides of the artery (semi lunar over the artery). The results are very good when combined with ipack and LIA.
Click to expand...
P.s. we like to see spread in similar fashion to what you described if possible, too (i.e. between the SFA and satorious)

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floridaboy18 said:
It is a good article, actually written by two of my mentors and the group I am joining next year ;-)

We haven't ventured into I Pack blocks yet, though. We normally do a single shot sciatic, adductor canal catheter, and spinal for TKAs. Take adductor catheter out on post op day 2.

What do you feel like you are covering with the i Pack block that is not covered by the above approach? Or is it an attempt to get same analgesic coverage without sacrificing posterior flexors (i.e. hamstrings)?

Sent from my SM-N910V using Tapatalk
Click to expand...

The ipack replaces the single shot sciatic block. I was amazed just how well they worked when done properly. I've have not done a single rescue sciatic block since implementing the ipack block.

Why risk foot drop or postoperative paresthesias in the sciatic nerve distribution when the ipack is good enough? In addition, patients can ambulate the same day and be discharged on postop day 1 or 2.
 
BLADEMDA said:
The ipack replaces the single shot sciatic block. I was amazed just how well they worked when done properly. I've have not done a single rescue sciatic block since implementing the ipack block.

Why risk foot drop or postoperative paresthesias in the sciatic nerve distribution when the ipack is good enough? In addition, patients can ambulate the same day and be discharged on postop day 1 or 2.
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Our surgeons perform a posterior capsule injection with morphine, toradol, and local I believe in addition to what we do.

Do your surgeons do these injections prior to closing as well or does the I Pack block replace this?

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floridaboy18 said:
Our surgeons perform a posterior capsule injection with morphine, toradol, and local I believe in addition to what we do.

Do your surgeons do these injections prior to closing as well or does the I Pack block replace this?

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Click to expand...

I do the ipack for a few of the older surgeons. The young guys do their own posterior capsule injection intraop.

The ipack is a posterior capsule injection under ultrasound. If the injection is done properly a sciatic nerve block isn't needed for the posterior knee pain.
 
OTCAwesome said:
I agree it probably has better coverage due to the adductor canal missing some of the perforaters. We've been doing them mostly for knees where the ortho wants them up and walking right after, I'd say 95% are super comfortable in the pacu. If continuous adductor, even better.
Click to expand...

Is your goal to please the ortho docs or the patients? If you were a patient which would you have for yourself? Would you really go with the adductor to get in that extra day of PT on POD 0? Does anyone really buy that rehab on POD 0 is better than POD 1? Not me...

Also about the US technique, maybe its not that the imager is failing to see the saphenous nerve due to poor US skill, maybe its that the other imager is easily convinced that a random piece of hyperechoic tissue sitting in the area that the book says it should be is the saphenous nerve and surrounds it with local... then drinks the placebo effect cool aid (surgeon is injecting local, antinflammatories, and narcotic in the knee anyways plus general, plus some femoral spread, lots of reasons a poorly done AC block will have decent results)

Just another perspective. I do believe it is a useful block, the more I do the more I believe. But I dont believe it to make any sense as it is inferior to FNB and we are only doing it to please surgeons at the possible detriment to patients.
 
Well you can argue that catheter succes rate isn't 100% some are misplaced some move or are pulled out. So a single shot acb + dexa gives you a good reliable analgesia for 24+h.
If patients are averaging 5-10mg of morphine for the first 48h post op they can't be that uncomfortable and you are therfore not gaining much with a Fem cath.
 
Hoya11 said:
Is your goal to please the ortho docs or the patients? If you were a patient which would you have for yourself? Would you really go with the adductor to get in that extra day of PT on POD 0? Does anyone really buy that rehab on POD 0 is better than POD 1? Not me...

Also about the US technique, maybe its not that the imager is failing to see the saphenous nerve due to poor US skill, maybe its that the other imager is easily convinced that a random piece of hyperechoic tissue sitting in the area that the book says it should be is the saphenous nerve and surrounds it with local... then drinks the placebo effect cool aid (surgeon is injecting local, antinflammatories, and narcotic in the knee anyways plus general, plus some femoral spread, lots of reasons a poorly done AC block will have decent results)

Just another perspective. I do believe it is a useful block, the more I do the more I believe. But I dont believe it to make any sense as it is inferior to FNB and we are only doing it to please surgeons at the possible detriment to patients.
Click to expand...

I agree that a Fem cath provides superior analgesia, but . . . we don't practice in a vacuum. If your orthopods are convinced that PT on DOS is beneficial (I have no idea whether it makes a lick o' difference or not - but they sure seem to think it does), and they ask you to provide an anesthetic that facilitates that, what are you gonna do?? You can't just say "F you, this MF'er is getting a Fem block!" Maybe for a big time chronic-painer I would make a case for the fem, but for the average run of the mill TKA an adductor works well and keeps the surgeon and pt happy - sorry if it doesn't keep you happy.

Also factor in that the fall risk is not zero after a fem block. I think it's a bit of a stretch to say that ACB's are a "detriment" to the pt.
 
Traditionally, the ACB is done at mid belly of the sartorious. I actually go more cephalad (higher up in the thigh) to try and pick off more fem. nerve fibers and get some proximal spread. I also use a crap ton of volume (25-30ccs). I haven't had <significant> quad weakness (yet). Anecdotally, I feel like my patients are more confy than the traditional approach. With LIA done appropriately, I am very satisfied with the analgesia that I see with my patients.
Pain scores are 0-3 over 24 hrs. which is pretty good all things considered.
 
Hoya11 said:
Is your goal to please the ortho docs or the patients? If you were a patient which would you have for yourself? Would you really go with the adductor to get in that extra day of PT on POD 0? Does anyone really buy that rehab on POD 0 is better than POD 1? Not me...

Also about the US technique, maybe its not that the imager is failing to see the saphenous nerve due to poor US skill, maybe its that the other imager is easily convinced that a random piece of hyperechoic tissue sitting in the area that the book says it should be is the saphenous nerve and surrounds it with local... then drinks the placebo effect cool aid (surgeon is injecting local, antinflammatories, and narcotic in the knee anyways plus general, plus some femoral spread, lots of reasons a poorly done AC block will have decent results)

Just another perspective. I do believe it is a useful block, the more I do the more I believe. But I dont believe it to make any sense as it is inferior to FNB and we are only doing it to please surgeons at the possible detriment to patients.
Click to expand...

1. I would want an Adductor canal block with exparel plus an ipack block with exparel
2. I wouldn't mind a single shot Femoral block upfront with 0.25% Ropivacaine as ambulation would not be impeded

So, I don't believe it is detrimental to patients whatsoever.
 
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BLADEMDA said:
1. I would want an Adductor canal block with exparel plus an ipack block with exparel
2. I wouldn't mind a single shot Femoral block upfront with 0.25% Ropivacaine as ambulation would not be impeded

So, I don't believe it is detrimental to patients whatsoever.
Click to expand...

So you yourself would rather less concentrated local in order to ambulate POD o ? Wow is all that I can say to that.

I agree that we dont practice in a vaccum and we do what the surgeon desires to some degree, which is the only reason i do the ACBs. And yes the patients are "happy" but could they be happier?
 
I know a couple of colleagues that do femorals when the orthopod always requests an adductor. They keep doing it because no one has said anything yet about it
 
Hoya11 said:
So you yourself would rather less concentrated local in order to ambulate POD o ? Wow is all that I can say to that.

I agree that we dont practice in a vaccum and we do what the surgeon desires to some degree, which is the only reason i do the ACBs. And yes the patients are "happy" but could they be happier?
Click to expand...

Younger patients (under age 70) can ambulate reasonably well with a Femoral Block using 0.25% Ropivacaine. That said, the block would only last about 10 hours or so.
 
However, a weakened quadriceps femoris muscle is a risk factor for falling in elderly patients, regardless of analgesia [38]. In the current study, two subjects fell (twice in one subject for a total of three falls), and both were in the Ropivacaine group (p = 0.240). There is growing evidence that lower extremity continuous peripheral nerve blocks increase the risk of patient falls [11,14,18,29,31,41]. Whether or not the cFNB was a contributing factor to the falls of the present study remains unknown because our investigation was not powered to detect such (presumably) rare complications [24]. Nonetheless, patient falls during perineural infusion are now being highlighted in the anesthesiology and surgical literature [11,23,29].

http://clinicaldepartments.musc.edu...ation/Journal Club/December 2012/article1.pdf
 
So pain and discomfort causes weakness as well.
However, These may be realized more days out.
 
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