regional question

[militarymd]

Here's a question to you regional gurus...from the president of SARA (Society Against Regional Anesthesia).

Teen age ASA1 (50kg) having some sort of ankle reconstruction. The family asked specifically for a popliteal fossa block.....so I did one.

8 cm proximal to the popliteal crease with the patient in prone position. 22 gauge stimuplex needle to locate sciatic nerve....inject at 0.4 mA with good twitches....30 cc of 0.25 % bupivicaine with 1:200,000 epi.

Turn her suplne, and put 10 cc of the same to the femoral nerve to get the saphenous nerve.

Put her to sleep for the case...

Now here is the weird part.

In the recovery room (1.5 hour case)...she had no pain, but she could move her toes.

Later in the day 6 hours later, she lost her motor function......ie the block got denser????

Anyone seen this before....I'm going to see her today for additional followup.
__________________

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[Gern Blansten]

Not a "guru," but I have not seen what you have described. I would pay special attention to the surgical site and make sure their is not any kind of hematoma or compartment syndrome with nerve compression going on. Is the dressing too tight? I have never heard of a clinically significant hematoma at the site of a politeal block, but I suppose it could theoretically happen. The only other thing might be if there was any kind of discrepancy in the initial exam. I suspect that you saw her yourself post op, but if you relied on someone else's exam, that could factor in some discrepancy. I will be interested to hear what you find when you see her.
I guess with this experience, this has sealed your decision to run for another term as president of SARA.

 

[Noyac]

I have no literature to prove this but I have seen blocks get denser as time goes on esp'ly with the weaker locals like 0.25% bupiv. I typically use something stronger like 0.5%. What I suppose is occurring, is absorption of the local into the nerve. But I agree with Gern, make sure there is not a hematoma or some other compression occurring. I usually us the max dose (50cc in her with 0.25% bupiv) in the popliteal block b/c i am relying on some absorption there. This is the only block that I rely on some absorption with since the nerve divides at different site in this area. And if I am doing a FNB as well then I save some for this site as well. But I rarely add the FNB to the popliteal. If the saphenous is involved postop then I do a FNB.

 

[fval28]

Here's a question to you regional gurus...from the president of SARA (Society Against Regional Anesthesia).

Teen age ASA1 (50kg) having some sort of ankle reconstruction. The family asked specifically for a popliteal fossa block.....so I did one.

8 cm proximal to the popliteal crease with the patient in prone position. 22 gauge stimuplex needle to locate sciatic nerve....inject at 0.4 mA with good twitches....30 cc of 0.25 % bupivicaine with 1:200,000 epi.

Turn her suplne, and put 10 cc of the same to the femoral nerve to get the saphenous nerve.

Put her to sleep for the case...

Now here is the weird part.

In the recovery room (1.5 hour case)...she had no pain, but she could move her toes.

Later in the day 6 hours later, she lost her motor function......ie the block got denser????

Anyone seen this before....I'm going to see her today for additional followup.
__________________

Guy I work with was in the Navy and said he would bring all of his patients in first thin in the morning, block all of them w/ marcaine, then go and do his 1st case, sleep the 1st guy and run MAC's on all the rest once the blocks had time to set up. He says marcaine (esp 0.25%) take a LOOOONG time to set up (1+hours).
One other thing I have noticed is that if I inject at 0.4, my blocks take longer to set up and I have noticed a higher failure rate. I try to get response all the way down to 0.2 and then come back up to 0.4 before injecting, find that that little bit makes a big difference (in my hands anyway).
But it sounds like you did a great block on this girl- maybe you should consider stepping down from your executive level position

 

[militarymd]

I saw her today. The block is wearing off. She got over 30 hours of good analgesia, and many more of residual analgesia.

I limit myself to 2 mg/kg of bupivicaine because we lack bypass capability...so hence 40 cc of 0.25 % in a 50kg teenager.

The block was setting up within 5 minutes of me placing it, that's why I was concerned when the block set up even more after 2+ hours of surgery and more time in the PACU.

I checked the injection sites, and there wasn't any evidence of bleeding or bruising....I had considered doing a quick ultrasound scan of the injection site, but because it was so atraumatic, I decided just to see her the next day.

 

[Spleen]

First year student here...

I'm curious how prevalent the 'SARA' opinion is and why a person would feel that way?

Mil,
What is your opinion of the Virginia Mason residency in Seattle that focuses on regional?

Thank you!

 

[militarymd]

First year student here...

I'm curious how prevalent the 'SARA' opinion is and why a person would feel that way?

Mil,
What is your opinion of the Virginia Mason residency in Seattle that focuses on regional?

Thank you!

S.A.R.A. tongue in cheek humor from my CCM half of my training where there is little use for it...

As for Virginia Mason....I hear good things about it....that's all that I can say. I have no personal experience with their program.

 

[Planktonmd]

I saw her today. The block is wearing off. She got over 30 hours of good analgesia, and many more of residual analgesia.

I limit myself to 2 mg/kg of bupivicaine because we lack bypass capability...so hence 40 cc of 0.25 % in a 50kg teenager.

The block was setting up within 5 minutes of me placing it, that's why I was concerned when the block set up even more after 2+ hours of surgery and more time in the PACU.

I checked the injection sites, and there wasn't any evidence of bleeding or bruising....I had considered doing a quick ultrasound scan of the injection site, but because it was so atraumatic, I decided just to see her the next day.

Good to hear.
Regional anesthesia is a great thing but when things go wrong they go really wrong.

 

[pmichaelmd]

I have also seen delayed onset of action, but we don't use bupiv or epi in any of our regional blocks because of potential for nerve ischemia, etc. We only use 0.5% ropivacaine because of theoretical decreases in cardiotoxicity and we are able to get 12-18 hours of good analgesia using it. We often extend this by placing catheters, but that is a luxury we have at an academic institution with a dedicated catheter service to follow catheters

That said, I echo the sentiment about nerve compression, etc. Have heard of slow leaks from popliteal artery from medial misadventure.

For the TARs, ankle fusions, etc., we usually do popliteal catheters with 35-40 ml 0.5% rop and a ring saphenous with same rop 0.5%, 5-10 ml. We've had pretty good success, particularly with Lyrica 150mg bid and celebrex 100 bid post op.

Anybody else use this technique?

Cheers,
PMMD

 

[The_Sensei]

Here's a question to you regional gurus...from the president of SARA (Society Against Regional Anesthesia).

Teen age ASA1 (50kg) having some sort of ankle reconstruction. The family asked specifically for a popliteal fossa block.....so I did one.

8 cm proximal to the popliteal crease with the patient in prone position. 22 gauge stimuplex needle to locate sciatic nerve....inject at 0.4 mA with good twitches....30 cc of 0.25 % bupivicaine with 1:200,000 epi.

Turn her suplne, and put 10 cc of the same to the femoral nerve to get the saphenous nerve.

Put her to sleep for the case...

Now here is the weird part.

In the recovery room (1.5 hour case)...she had no pain, but she could move her toes.

Later in the day 6 hours later, she lost her motor function......ie the block got denser????

Anyone seen this before....I'm going to see her today for additional followup.
__________________

This is why I limit my use of regional anesthesia to the bare bones (i.e. interscalenes, axillary) if I MUST.

 

[amyl]

regional/pain question -- I have a patient (geriatric) with severe arterial neuropathy remaining after placement of two popliteal stents. She is in agony! Think this kind of block would help her - if yours lasted 30 h... she could go twice a week?

 

[Planktonmd]

regional/pain question -- I have a patient (geriatric) with severe arterial neuropathy remaining after placement of two popliteal stents. She is in agony! Think this kind of block would help her - if yours lasted 30 h... she could go twice a week?

Twice a week for the rest of her life?

If nothing works she might benifit from an intrathecal morphine + clonidine pump.

 

[amyl]

she is 97 so the rest of her life is relative. she is in a lot of pain, just trying to come up with anything to help her. thanks for the input

 

[Planktonmd]

she is 97 so the rest of her life is relative. she is in a lot of pain, just trying to come up with anything to help her. thanks for the input

Ok, that makes a difference, if she is 97 then here is what I would do:
1- A small dose of a TCA every night, try Amytriptilin 12.5 mg.
2- A small dose of a long acting narcotic: how about Kadian 20 mg once a day assuming she is not taking big doses of narcotics right now, and don't forget to give her a laxative with that.
3- A shot of her favorite alcoholic drink and/or a Vicodin PRN for break through pain.
She will feel better with this tratment, I guarantee it.

 

[ketafol]

Ok, that makes a difference, if she is 97 then here is what I would do:
1- A small dose of a TCA every night, try Amytriptilin 12.5 mg.
2- A small dose of a long acting narcotic: how about Kadian 20 mg once a day assuming she is not taking big doses of narcotics right now, and don't forget to give her a laxative with that.
3- A shot of her favorite alcoholic drink and/or a Vicodin PRN for break through pain.
She will feel better with this tratment, I guarantee it.

night night sweetr old lady

 

[Noyac]

Yeah, there is very little in the realm of regional that can help this lady. I doubt even lumbar sympathetic blocks would do much and if it did you can't jut keep doing them.

I'd go with the medication route.

 

[jetproppilot]

she is 97 so the rest of her life is relative. she is in a lot of pain, just trying to come up with anything to help her. thanks for the input

I hope I have pain when I'm 97.

Cuz that'd mean I'm 97.

If I make it that far, and had a pain problem, no needles for me.

I'd, uhhhhhh, break out the con bud. I've heard one-hit is all it takes.

Inhale.."WHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHUUUUPPPP."

"ERE".

Put a little Cypress Hill in the sound system, and groove to the potsmokinn' rokkstars:

yes I smoke s hit, straight off the roach clip

I roach it, roll the blunt at once to approach it

forward motion makes you sway like the ocean

the herb is much more than a powerful potion...

And pour a Petrone margarita.

Double shot.

And log on to PokerStars.net.

 

[Noyac]

I hope I have pain when I'm 97.

Cuz that'd mean I'm 97.

If I make it that far, and had a pain problem, no needles for me.

I'd, uhhhhhh, break out the con bud. Put a little Cypress Hill in the sound system.

And pour a Petrone margarita.

Double shot.

And log on to PokerStars.net.

I can respect that but my taste is a little different.

I want the needles, Load me up, morphine, heroin, you name it.

Poor me a Reyka Vodka martini.

And Some Black Keys in the background.

 

[mille125]

regional/pain question -- I have a patient (geriatric) with severe arterial neuropathy remaining after placement of two popliteal stents. She is in agony! Think this kind of block would help her - if yours lasted 30 h... she could go twice a week?

I would not do a popliteal nerve block or catheter (short term relief if any and a waste of time). I think that the best option is a tunnelled epidural catheter. That would provide good relief in the least invasive route. If she were younger, I would suggest SCS. Opioids are also an option. I disagree with kadian, however. Morphine is not a great choice in the elderly (especially at 97). Even if her serum creatinine is normal, her creatinine clearance is likely markedly impaired. Morphine just is not a good drug in this scenario (M6G). With all of this said, there are definitely good options. If in doubt, refer her to a pain specialist. We see this type of patient frequently.......

 

[jetproppilot]

I would not do a popliteal nerve block or catheter (short term relief if any and a waste of time). I think that the best option is a tunnelled epidural catheter. That would provide good relief in the least invasive route. If she were younger, I would suggest SCS. Opioids are also an option. I disagree with kadian, however. Morphine is not a great choice in the elderly (especially at 97). Even if her serum creatinine is normal, her creatinine clearance is likely markedly impaired. Morphine just is not a good drug in this scenario (M6G). With all of this said, there are definitely good options. If in doubt, refer her to a pain specialist. We see this type of patient frequently.......

Nope.

Wrong route.

See Noy and I's post's above.

 

[mille125]

Here's a question to you regional gurus...from the president of SARA (Society Against Regional Anesthesia).

Teen age ASA1 (50kg) having some sort of ankle reconstruction. The family asked specifically for a popliteal fossa block.....so I did one.

8 cm proximal to the popliteal crease with the patient in prone position. 22 gauge stimuplex needle to locate sciatic nerve....inject at 0.4 mA with good twitches....30 cc of 0.25 % bupivicaine with 1:200,000 epi.

Turn her suplne, and put 10 cc of the same to the femoral nerve to get the saphenous nerve.

Put her to sleep for the case...

Now here is the weird part.

In the recovery room (1.5 hour case)...she had no pain, but she could move her toes.

Later in the day 6 hours later, she lost her motor function......ie the block got denser????

Anyone seen this before....I'm going to see her today for additional followup.
__________________

I would not call myself a "guru" because I do not do a lot of peripheral nerve blocks now. However, in residency I did several hundred sciatic, lumbar plexus, and femoral blocks. I must say that I think your case is one of delayed spread of local anesthetic. I have seen it happen myself in a few of the combined lumbar plexus/sciatic blocks for TKA. For surgeries that are less than 2 hrs, I usually used a mix of mepivicaine with ropivicaine which prevents the block from lasting quite so long and insures faster onset. However, what you describe is not unusual given the local anesthetic that you chose. However, I would definitely access for compartment syndrome or hematoma as others have suggested.

 

[sdn1977]

OK - I'll bite once (hides head ).

You didn't give too much info about this young lady Mil and you didn't mention that the initial response you got was unexpected.

Thus, I'm guessing that the pH of the tissues was sufficient & appropriate for the anesthetic & epi to stay where they should be to give the effect you want.

But....why did the effect seem to get "deeper" at the time you expected it to lessen - right?

Well....it may be tissue diffusion due to the metabolism of epi, but if that were the case.....you'd just see the same amount or less of the anesthetic you observed in PACU - you'd still see toe wiggling & somewhat less since you'd have the same amount of drug (altho metabolism would have taken care of some of that) but over a wider range.

So...its just my supposition you have one of 3 things going on & you probably won't ever know what it was.

With local anesthetics, protein binding is directly related to the duration of effect. The more firmly the anesthetic binds to the protein of the sodium channel, the longer duration of effect. This is often a genetic characteristic. She might have had a history of "long" periods of anesthesia after dental injections which could indicate an unusual protein binding effect.

Or.....it could be related to metabolism. Amide type anesthetics like bupivacaine are metabolized by cytochrome P-450 3A4, which has a genetic component but can also be inhibited by liver disease (not probably the case in this young lady) but also by drugs....such as tetracycline (does she have acne?), SSRI's, & antifungals (has she used fluconazole in the last week or so???) as well as benzodiazepines (probably not the ones you gave her, but perhaps from other sources).

Finally, she might have been (you didn't mention) a larger girl with more adipose tissue in the area you injected, which allowed more distribution of the drug there. Potency of anesthetics is directly related to its lipophilicity. If a drug is very lipophilic & there is a lot of lipophilic tissue around, that tissue will act as a drug depot & come out very slowly when in equilibrium. However....if this were the case, you wouldn't have gotten the reaction you expected initially at the time you got it - it would have been slower since distribution would take place & not allow the drug to act on the typ C fibers. Likewise, the effect wouldn't necessarily be "deeper" - just longer.

Anyway - my guess is delayed metabolism which combined with tissue diffusion after the epi wore off & allowed you to see the effect of anesthesia which went beyond the region you originally intended & didn't metabolize in the time you expected. It became apparently "deeper" because the epi was gone which allowed the amide access to more of the type A fibers rather than what the original intent was which I think was more of the type C fibers.

But - then I might be completly off base entirely......"goes back under the covers"

 

[coccygodynia]

Welcome Back SDN!!!

 

[OldManDave]

I hope I have pain when I'm 97.

Cuz that'd mean I'm 97.

If I make it that far, and had a pain problem, no needles for me.

I'd, uhhhhhh, break out the con bud. I've heard one-hit is all it takes.

Inhale.."WHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHUUUUPPPP."

"ERE".

Put a little Cypress Hill in the sound system, and groove to the potsmokinn' rokkstars:

yes I smoke s hit, straight off the roach clip

I roach it, roll the blunt at once to approach it

forward motion makes you sway like the ocean

the herb is much more than a powerful potion...

And pour a Petrone margarita.

Double shot.

And log on to PokerStars.net.

Oh yeah Baby! You & I think alike...sorta. However, my mix would be a bit different. A DEFINITE on the herbage + waterpipe, but my tunes would lean more toward the classics: Pink Floyd, Zeppelin, Cure & so on. I live for great tunes!!! And, to wash it down - a fine single-malt on the rocks w/ a tiny splash of H2O...I gotta keep myself well-hydrated & protect my beans at such a ripe/rotten old age!!!

 

[jeesapeesa]

i've been reading sdn for a while and always i get a kick out of your posts. im taking my mcats this friday and i was wondering what you got wen you took it (out of sheer curiousity). sorry if im hijacking but i'm curious.

 

[BLADEMDA]

i've been reading sdn for a while and always i get a kick out of your posts. im taking my mcats this friday and i was wondering what you got wen you took it (out of sheer curiousity). sorry if im hijacking but i'm curious.

Blade

 

[jeesapeesa]

well, out of inspiration too, i suppose. how bout you, blade?

 

[BLADEMDA]

well, out of inspiration too, i suppose. how bout you, blade?

I really don't remember all the scores but they were considerably above the mean. After all, that is what counts- your score relative to everyone else's.
In my day they used a number on each category (I think) with 8 being average. I scored above 10 in everything with a few 12's.

Honestly, so MANY exams in my career and now CME's with optional recertification for us oldies which I will take next year. The recertification exam is offered to those with unlimited time certificates through 2009 then we must enter the new pathway if we want recertification. I plan on doing the right thing like the new boys/girls are required to do.

I think the NMBE Part 1 (now USLE part 1) was much harder than the MCAT.
In fact, Part 1 may have been the most difficult test I took in my career.

Do the best you can on the MCAT and remember it is ONE exam on a long list of exams to follow during your career.

I am really looking forward to JPP's post.

 

[sdn1977]

i've been reading sdn for a while and always i get a kick out of your posts. im taking my mcats this friday and i was wondering what you got wen you took it (out of sheer curiousity). sorry if im hijacking but i'm curious.

I must confess......I never took the MCAT. I'm a pharmacist, not a physician....so only can comment on the aspects of drugs which pharmacists might be involved in - kinetics, genetic differences, dynamics, compatibilities - stuff like that. You're really not that interested in testing of pharmacists...so I won't comment.

But, I do know how stressful the MCAT is - my daughter took it. She's past that now & past Step I, so I have to agree with Blade - there are many, many tests in the path to where you're going. Fortunately, she's becoming a bit more relaxed about them as time goes on, which makes my life easier as a parent. Sadly......pharmacology is not one of her interests (where did I go wrong ?).

But - good luck on Friday and enjoy the journey!!!

 

[Noyac]

OK - I'll bite once (hides head ).

You didn't give too much info about this young lady Mil and you didn't mention that the initial response you got was unexpected.

Thus, I'm guessing that the pH of the tissues was sufficient & appropriate for the anesthetic & epi to stay where they should be to give the effect you want.

But....why did the effect seem to get "deeper" at the time you expected it to lessen - right?

Well....it may be tissue diffusion due to the metabolism of epi, but if that were the case.....you'd just see the same amount or less of the anesthetic you observed in PACU - you'd still see toe wiggling & somewhat less since you'd have the same amount of drug (altho metabolism would have taken care of some of that) but over a wider range.

So...its just my supposition you have one of 3 things going on & you probably won't ever know what it was.

With local anesthetics, protein binding is directly related to the duration of effect. The more firmly the anesthetic binds to the protein of the sodium channel, the longer duration of effect. This is often a genetic characteristic. She might have had a history of "long" periods of anesthesia after dental injections which could indicate an unusual protein binding effect.

Or.....it could be related to metabolism. Amide type anesthetics like bupivacaine are metabolized by cytochrome P-450 3A4, which has a genetic component but can also be inhibited by liver disease (not probably the case in this young lady) but also by drugs....such as tetracycline (does she have acne?), SSRI's, & antifungals (has she used fluconazole in the last week or so???) as well as benzodiazepines (probably not the ones you gave her, but perhaps from other sources).

Finally, she might have been (you didn't mention) a larger girl with more adipose tissue in the area you injected, which allowed more distribution of the drug there. Potency of anesthetics is directly related to its lipophilicity. If a drug is very lipophilic & there is a lot of lipophilic tissue around, that tissue will act as a drug depot & come out very slowly when in equilibrium. However....if this were the case, you wouldn't have gotten the reaction you expected initially at the time you got it - it would have been slower since distribution would take place & not allow the drug to act on the typ C fibers. Likewise, the effect wouldn't necessarily be "deeper" - just longer.

Anyway - my guess is delayed metabolism which combined with tissue diffusion after the epi wore off & allowed you to see the effect of anesthesia which went beyond the region you originally intended & didn't metabolize in the time you expected. It became apparently "deeper" because the epi was gone which allowed the amide access to more of the type A fibers rather than what the original intent was which I think was more of the type C fibers.

But - then I might be completly off base entirely......"goes back under the covers"

YOu know SDN, I was thinking the exact thing.

This post just shows what we have been missing with your absence. What ever we did, please forgive us and never leave us alone again.

 

[jeesapeesa]

I must confess......I never took the MCAT. I'm a pharmacist, not a physician....so only can comment on the aspects of drugs which pharmacists might be involved in - kinetics, genetic differences, dynamics, compatibilities - stuff like that. You're really not that interested in testing of pharmacists...so I won't comment.

But, I do know how stressful the MCAT is - my daughter took it. She's past that now & past Step I, so I have to agree with Blade - there are many, many tests in the path to where you're going. Fortunately, she's becoming a bit more relaxed about them as time goes on, which makes my life easier as a parent. Sadly......pharmacology is not one of her interests (where did I go wrong ?).

But - good luck on Friday and enjoy the journey!!!

thanks. i realize that it's one of many and is probably the single most important one -- it decides whether you actually get in or not. my ex gf is a pharmacist but she never had to take the pmat since she stayed in california -- enjoys her work and gets tons of overtime. i am assuming that jet, mil, noyac, blade, et al probably had high scores on the test.

 

[Noyac]

thanks. i realize that it's one of many and is probably the single most important one -- it decides whether you actually get in or not. my ex gf is a pharmacist but she never had to take the pmat since she stayed in california -- enjoys her work and gets tons of overtime. i am assuming that jet, mil, noyac, blade, et al probably had high scores on the test.

Not me.

 

[jetproppilot]

i've been reading sdn for a while and always i get a kick out of your posts. im taking my mcats this friday and i was wondering what you got wen you took it (out of sheer curiousity). sorry if im hijacking but i'm curious.

I took it in the late eighties. It was scored different back then.

I scored in the fifties...cant remember the exact number... which was a respectable score.

I think 75 was perfect.

I knew one dude who got a 70.

Most people I knew got in the fifties.

 

[militarymd]

It's been so long...I can't remember.

 

[epidural man]

regional/pain question -- I have a patient (geriatric) with severe arterial neuropathy remaining after placement of two popliteal stents. She is in agony! Think this kind of block would help her - if yours lasted 30 h... she could go twice a week?

She sounds like a perfect patient for a spinal cord stimulator. I have seen excellent results in similar type patients. Send her to someone that can give her a stimulator trial. It could really change her life.

 

[urgewrx]

i am assuming that jet, mil, noyac, blade, et al probably had high scores on the test.

These *****s?

No way!!!!
















Disclamer: I have no idea about their scores.