Peripheral Nerve Block Duration

[jetproppilot]

What kinda times are you studs seeing outta your blocks, interscalene, popliteal, femoral et al?
Our ultrasound blocks have ranged from 12 to 24 hours, with most lasting around 12-14 hours.
We've done around 40 ultrasound guided blocks so far.

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[BLADEMDA]

What kinda times are you studs seeing outta your blocks, interscalene, popliteal, femoral et al?
Our ultrasound blocks have ranged from 12 to 24 hours, with most lasting around 12-14 hours.
We've done around 40 ultrasound guided blocks so far.

This month's Regional Journal (ASRA) speculated that the amount of local injected under U/S affected block duration. Non U/S guided blocks lasted longer in the study because a larger volume was used. I suspect more studies will be coming soon. If you are using 10-15 mls with U/S the block will work but may cut short the duration.

In my experience Bupivacaine gives the longest duration blocks (don't mix it with anything). I use a minimum of 20-25 mls for my single shot blocks and routinely get 20-24 hours of post op pain relief. Since you are using u/s why not consider going back to Bupivacaine? Many of switched to Ropivacaine for safety when doing blind/nerve stimulator only blocks. But, now we can see the blood vessels and nerves.

 

[dhb]

I aim for overnight relief so 16-24h. I've been adding dexamethasone 10mg with good succes. Some blocks came out short but most lasted overnight.

 

[BLADEMDA]

I aim for overnight relief so 16-24h. I've been adding dexamethasone 10mg with good succes. Some blocks came out short but most lasted overnight.

We have discussed Decadron in another thread. Duration is prolonged but the evidence of safety in all patient populations is lacking. I would avoid Decadron in Diabetcs ( we can debate type 1 vs 2 and those without peripheral neuropathy) and other conditions affecting the nervous system. If I were to use Decadron in a younger, healthier patient it would be Preservative free Decadron in a 4mg dose.

 

[sevoflurane]

Depends on what LA you use, site, adjuvants and total mg.

But generally 18-26 hrs.

I've had some go wicked long....

 

[dhb]

We have discussed Decadron in another thread. Duration is prolonged but the evidence of safety in all patient populations is lacking.

In this specific indication yes but steroids have been used extensively in all forms since a very long time. Evidence based it isn't but i talked to someone from a group that had been using steroids in their PNB for 15+ years apparently without any problems.

 

[Oggg]

12-24h is about right.
Mostly 18h since I started using US. Clonidine didn't seem to help, and the research goes both ways, so i stopped after a few pts. Now I am trying out dexamethasone 4mg.

 

[BLADEMDA]

In this specific indication yes but steroids have been used extensively in all forms since a very long time. Evidence based it isn't but i talked to someone from a group that had been using steroids in their PNB for 15+ years apparently without any problems.[/QUOT

In the USA all it takes is one "problem" to call your miracle cocktail into question. I prefer my practice to be evidence based plus my decades of experience. Decadron may turn out to be a great adjunct for our blocks but for all patient populations? Would you really add 10 mg Decadron to your local for an 80 year old diabetic with peripheral neuropathy and preexisting neurological disorder? In Europe you won't have a problem but in the USA caution and prudence may be advisable.

 

[Endee]

For my hand surgery, my anesthesiologist did a nerve stim supraclavicular block. Complete motor block lasted about 9 hours. Complete sensory block lasted another few hours, and analgesia lasted until the next morning, so probably about 20-24 hours.

 

[IN2B8R]

What kinda times are you studs seeing outta your blocks, interscalene, popliteal, femoral et al?
Our ultrasound blocks have ranged from 12 to 24 hours, with most lasting around 12-14 hours.
We've done around 40 ultrasound guided blocks so far.

I always tell patients that, on average, they can count on 12-14 hours of "numbness." I use 0.5% Ropivicaine, 15-30 mL for brachial plexus blocks (all my blocks are u/s guided). If my intent is to have a distal, longer lasting block, I tend to use the 30 mL volume. If all I am doing is a shoulder arthroscopy, I will go as low as 15 mL's. People who have been doing this long enough will tell you that, in terms of LA's toxicity, there is greater inter-patient variability than inter-LA agent variability (the whole Ropivicaine is safer than Bupivicaine argument...).

 

[bostonblaz]

.5% Marcaine with epi 1:400 k 30 cc for every block and I do all with ultrasound. I get on average 21.5 hours for interscalene, 23 for femoral, 16 for axillary, 36 for popletial/saph and 20 for infraclavicular. I have just started with adding dexamethasone 4mg and I have about 30 mail back questionares to go through and do the numbers and will have much more data after a few more months but it is looking like it pushes all of the average times into the 30 hour mark. Blaz

 

[thegasman]

In my experience Bupivacaine gives the longest duration blocks (don't mix it with anything). I use a minimum of 20-25 mls for my single shot blocks and routinely get 20-24 hours of post op pain relief. Since you are using u/s why not consider going back to Bupivacaine? Many of switched to Ropivacaine for safety when doing blind/nerve stimulator only blocks. But, now we can see the blood vessels and nerves.

Agree with this. I was using 0.5% ropiv with 1:400K epi and getting 12 hours. Now that I am using exclusively US guidance I have gone to 30 cc 0.5% bupiv with 1:200K and block time is more like 18-24 hours. Not too worried about increased toxicity since I can see the injection of local.

 

[dhb]

Would you really add 10 mg Decadron to your local for an 80 year old diabetic with peripheral neuropathy and preexisting neurological disorder?

No

 

[BLADEMDA]

.5% Marcaine with epi 1:400 k 30 cc for every block and I do all with ultrasound. I get on average 21.5 hours for interscalene, 23 for femoral, 16 for axillary, 36 for popletial/saph and 20 for infraclavicular. I have just started with adding dexamethasone 4mg and I have about 30 mail back questionares to go through and do the numbers and will have much more data after a few more months but it is looking like it pushes all of the average times into the 30 hour mark. Blaz

Thanks for sharing the info. I would love to read your posts concerning patient feedback on adding the Decadron. If 4 mg gets us to 24-30 hours consistently for post op pain relief then that's the right amount to add. If and when you Decide to add the decadron to "at risk groups" like diabetics please share you feedback with us.

 

[BLADEMDA]

Agree with this. I was using 0.5% ropiv with 1:400K epi and getting 12 hours. Now that I am using exclusively US guidance I have gone to 30 cc 0.5% bupiv with 1:200K and block time is more like 18-24 hours. Not too worried about increased toxicity since I can see the injection of local.

We are seeing eye to eye on this issue. I wonder if adding Decadron 4mg to you Bup mixture would prolong analgesia to 30 hours? Are you thinking of adding the PF Decadron to your cocktail?

 

[sevoflurane]

Thanks for sharing the info. I would love to read your posts concerning patient feedback on adding the Decadron. If 4 mg gets us to 24-30 hours consistently for post op pain relief then that's the right amount to add. If and when you Decide to add the decadron to "at risk groups" like diabetics please share you feedback with us.

Blade... I believe there is a paper on exactly this. Lower dose was just as beneficial as higher dose. No need for 10mg.

 

[sevoflurane]

Here ya go....

http://www.ncbi.nlm.nih.gov/pubmed/21681533

June 17th 2011

 

[jetproppilot]

Depends on what LA you use, site, adjuvants and total mg.

But generally 18-26 hrs.

I've had some go wicked long....

I appreciate all responses here and on the Ultrasound Is The Bomb thread.

Did an ultrasound guided interscalene block yesterday.

Young cooperative easy going dude, athlete.

Block lasted until 9pm when his shoulder started to "wake up". I'm big on educating the patient to begin taking opioids as soon as the "twinges" start; not to wait for excruciating pain. He took a Percocet at 9pm and went to bed. Awoke at 3am to take a whizz, had "some" pain, took another Percocet. This morning he described his shoulder as "tender" but very manageable.

So 14 hours 'till first "twinge."

Guess that's good but lemme ask you some technical questions:

1) I'm pretty good now with visualizing the needle tip upon initial insertion. I see the anterior and middle scalene muscle bellies with the hypoechogenic plexi branches sandwiched in between or something close to that. I generally aim for the middle, guide it right up there, check for twitch, yeah ok got a twitch down to .28, disappears below that,

INJECT THE LOCAL HOLDING POSITION.

2) Are you studs say, on an interscalene, guiding superior, squirt some, guiding middle, squirt some, guiding inferior, etc etc?

I'm thinking in advance that would help consistently prolong my blocks but once I get a super good visualization of the anatomy and subsequently guide needle tip to exactly where I want it I'm hesitant to let go of that picture so to speak since yeah, I can find the anatomy, guide the needle, and squirt the local but

I don't wanna let go of my great view once I got it!

3) Is that the answer to consistently longer blocks?

Moving the needle around under live ultrasound guidance, with a little SPRINKLE here, a little SPRINKLE there?

Or, can you shoot for middle ground, abutting the plexi with your needle, squirt the local, and achieve the same

ENDPOINT?

CHIME IN, ALL ULTRASOUND

SENSAIS!

 

[epidural man]

Here ya go....

http://www.ncbi.nlm.nih.gov/pubmed/21681533

June 17th 2011

This study has some peculiarities which I think significantly weaken the study. First of all, the evaluations were done by forms that were filled in and sent later. Who knows when the patient actually filled the sheet in. They were not called until weeks later. This presents a BIG problem for the study. Second, the groups are not matched - not a big deal, but a problem nonetheless. Thirdly, there is no systemic control. Is the steroid a systemic or local affect? This lack of control make the results essentially useless in my mind. Fourth, WTF about motor block outlasting analgesia. Also, it seems that the steroid significantly prolonged motor block far beyond that of analgesia. This is NOT what I want happening with blocks - in fact, I want the exact opposite.

Candido has done two studies with buprenorphine - and he inlcuded a systemic control in both. In both studies, the additive prolonged analgesia. I really like the axillary bock study with a short acting LA. In this study, he was able to prolong the block as far out as I would expect a bupivicaine block should work. The reason this is significant for me is because I would hate to have a bupivicaine toxicity cardiac event - I know it is rare - but holy crap that would suck. If I can use the relatively safe mepivicaine - and get the same duration I would with bupivicaine - why would I not do that? And the block sets up much faster.

 

[sevoflurane]

I appreciate all responses here and on the Ultrasound Is The Bomb thread.

Did an ultrasound guided interscalene block yesterday.

Young cooperative easy going dude, athlete.

Block lasted until 9pm when his shoulder started to "wake up". I'm big on educating the patient to begin taking opioids as soon as the "twinges" start; not to wait for excruciating pain. He took a Percocet at 9pm and went to bed. Awoke at 3am to take a whizz, had "some" pain, took another Percocet. This morning he described his shoulder as "tender" but very manageable.

So 14 hours 'till first "twinge."

Guess that's good but lemme ask you some technical questions:

1) I'm pretty good now with visualizing the needle tip upon initial insertion. I see the anterior and middle scalene muscle bellies with the hypoechogenic plexi branches sandwiched in between or something close to that. I generally aim for the middle, guide it right up there, check for twitch, yeah ok got a twitch down to .28, disappears below that,

INJECT THE LOCAL HOLDING POSITION.

2) Are you studs say, on an interscalene, guiding superior, squirt some, guiding middle, squirt some, guiding inferior, etc etc?

I'm thinking in advance that would help consistently prolong my blocks but once I get a super good visualization of the anatomy and subsequently guide needle tip to exactly where I want it I'm hesitant to let go of that picture so to speak since yeah, I can find the anatomy, guide the needle, and squirt the local but

I don't wanna let go of my great view once I got it!

3) Is that the answer to consistently longer blocks?

Moving the needle around under live ultrasound guidance, with a little SPRINKLE here, a little SPRINKLE there?

Or, can you shoot for middle ground, abutting the plexi with your needle, squirt the local, and achieve the same

ENDPOINT?

CHIME IN, ALL ULTRASOUND

SENSAIS!

Hey jet...

Glad you are digg'n USD. It is fun as hell and is def. gonna help you in the more challenging patients. Learning curve isn't so steep either. I think you'll be a master USD blocking machine in no time.

As for your questions...

I never let go of my probe or my needle. I like to see the LA as it is being pushed. I have my nurses run the stimulator, aspirate, and slowly inject X volume with asp. q5cc's intervals. They also freeze and save my USD images which then get uploaded via wifi for billing. Pretty easy actually... especially since they usually have my patients prepped and ready to go. The hole thing doesn't take but a couple of minutes if set up correctly. I'm pretty sure you have the help you need where you are at.

With regards to squirting here and there... I don't do that unless I see a reason to do so. For example, once in a while when you do a supraclav, you will see your target on both sides of the artery. I'll def. selectively hit them both.

Or say I'm injecting and the LA is forming a crescent superiorly. I might reposition my needle tip to get underneath my honeycomb target, ultimately getting a complete doughnut around the target at hand.... but not always. Just depends on what lives around the nerve. If I see a couple of red and blue land mines in the area, I'll just take one pass and be happy with my twitch. They wake up comfy...

If you are going for axillary n.b. under USD... I'll pick off the MC independently and may take a couple of passes to make sure I get in front and behind the artery as the nerves like to live in both locations. I don't think this is completely necessary however.

So... generally, I don't move my needle around as it can cause some discomfort to my patients and I don't think it's necessary. All bets are off if I have an unusual stim response for the procedure (ie. diaphragm/trap for ISB=very rare with USD). I get the twitch I want and go for it. For ISB, delt, biceps, triceps or any twitch in the forearm (I don't take the pectoralis although some do). I usually back off if I'm below .4ma.

This is just the way I do my blocks. I'm sure others differ.

Hope this helps out in your quest.

 

[sevoflurane]

CHIME IN, ALL ULTRASOUND

SENSAIS!

I'm no sensai, just a dude that likes what he does.

 

[Planktonmd]

Any of you adding Buprenorphine to your local?
I have been doing it for a few years and I feel it is doing something.
My interscalene analgesia is frequently 24 hours.

 

[epidural man]

Any of you adding Buprenorphine to your local?
I have been doing it for a few years and I feel it is doing something.
My interscalene analgesia is frequently 24 hours.

Yep - did it today.

 

[bostonblaz]

JET, I have not seen any real difference in the set of patients that I have done when it comes to position of local. I do have a way I do it. I drive the needle and I inject the local. If it is my butt on the line I want that last modality of feel to be sure I am not injecting somewhere I am not sposed to. I do 1-2 cc right out side of the scaline goove. I pop in and drop 5cc and watch it spread. I scan up and down as I do so and if I see spread up and down along the space along the nerves(both caudad and cephalad). Once I know I am spreading the way I like and I drop the rest. I do the same thing for all other sites as well except for paravertibral. I dont reposition after that if I get the spread. I leave a whole 30 cc's. The only time I have a true target is when I leave a continous cath. I like to leave the tip of the cath on the medial side of the plexus cause it will move over the course of the next five days. blaz

 

[jetproppilot]

Any of you adding Buprenorphine to your local?
I have been doing it for a few years and I feel it is doing something.
My interscalene analgesia is frequently 24 hours.

Wow thats awesome.

Mine aren't.

Interscalene from yesterday...nurse called her this AM....14 hours...not shabby but can be better.

Thanks for the technical feedback Sevo and everyone.

 

[sevoflurane]

Any of you adding Buprenorphine to your local?
I have been doing it for a few years and I feel it is doing something.
My interscalene analgesia is frequently 24 hours.

One of my partners used to use buprenophine in all his blocks. He swore by it. Now he uses depomedrol.

 

[thegasman]

I appreciate all responses here and on the Ultrasound Is The Bomb thread.

Did an ultrasound guided interscalene block yesterday.

Young cooperative easy going dude, athlete.

Block lasted until 9pm when his shoulder started to "wake up". I'm big on educating the patient to begin taking opioids as soon as the "twinges" start; not to wait for excruciating pain. He took a Percocet at 9pm and went to bed. Awoke at 3am to take a whizz, had "some" pain, took another Percocet. This morning he described his shoulder as "tender" but very manageable.

So 14 hours 'till first "twinge."

Guess that's good but lemme ask you some technical questions:

1) I'm pretty good now with visualizing the needle tip upon initial insertion. I see the anterior and middle scalene muscle bellies with the hypoechogenic plexi branches sandwiched in between or something close to that. I generally aim for the middle, guide it right up there, check for twitch, yeah ok got a twitch down to .28, disappears below that,

INJECT THE LOCAL HOLDING POSITION.

2) Are you studs say, on an interscalene, guiding superior, squirt some, guiding middle, squirt some, guiding inferior, etc etc?

I'm thinking in advance that would help consistently prolong my blocks but once I get a super good visualization of the anatomy and subsequently guide needle tip to exactly where I want it I'm hesitant to let go of that picture so to speak since yeah, I can find the anatomy, guide the needle, and squirt the local but

I don't wanna let go of my great view once I got it!

3) Is that the answer to consistently longer blocks?

Moving the needle around under live ultrasound guidance, with a little SPRINKLE here, a little SPRINKLE there?

Or, can you shoot for middle ground, abutting the plexi with your needle, squirt the local, and achieve the same

ENDPOINT?

CHIME IN, ALL ULTRASOUND

SENSAIS!

I usually go for at least two needle locations, for example one on the inferior aspect of the plexus and one near the superior aspect. Sometimes 3-4 different locations depending on how I see the local spread. This just looks nice to see the local spread uniformly around the plexus. Multiple injections (at least 2) are frequently recommended when performing ultrasound blocks to increase success rate. In my experience they do not significantly increase block duration, nor does the use of ultrasound by itself. I use ultrasound only no stimulator. If you want longer blocks you must alter your local anesthetic solution. I havent used decadron yet, have been pretty happy with 30 cc 0.5% marcaine with epi giving 18-24 hrs.

 

[C.P.]

CHIME IN, ALL ULTRASOUND

SENSAIS!

Honestly, once you get better at needle visualization, it all depends on the local spread and where your targets are.
The thing that makes people nervous is moving the needle once you've started injection (i.e. likely killed you nerve stimulator twitch that was reassuring you before).
If I get a nice puddle of local, I'll happily float my needle around inside it to different corners, doing a little "hydrodissection" to increase the direction of favourable local spread.

For other blocks, where simply injecting volume may not always push the local to all the targets, then I'll strategically insert the needle in different areas to accomplish more effective spread (for example, on an axillary block, I'll usually hit the ulnar nerve first, then withdraw slowly while injecting, pausing around the median nerve. withdraw further, and if needed, re-insert the needle deeper, under the artery for the radial nerve. coming back to the skin, but not out, I'll then drop the needle steeply down to hit the musculocutaneous, which is usually almost below my original needle insertion site.

The tough thing about Ultrasound guided blocks is that there are numerous aspects of the block that provide you with feedback. Some of them you have to give up to others, like injecting. The resistance on injection and the ease of injection, both provide excellent feedback as to the likely location of the needle.

Regardless of the type of block, if my local isn't spreading the way I want it, instead of dumping potentially unnecessary volume into the spot and crossing my fingers, I'll reposition and increase the spread.