Isobaric spinal

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bigeyedfish

bigeyedfish

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Is anyone doing isobaric spinals? What are you using for your solution? Are you mixing it or is it a prepared solution? As far as I can tell in the US 0.5% and .25% bupivacaine aren't approved for spinal, even if they're preservative free.

I have an attending who's used to using isobaric (he's from out of the country) and he's hounding me to find him an isobaric solution.
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http://www.rxlist.com/cgi/generic/bupivacaine_ids.htm

Just grab the 0.5% single use, preservative free vials from OBS or your epidural cart. Good enough for Epidural = good enough for spinals in most of the world.

Marcaine (bupivicaine) 0.5% is beautiful for longer hips, knees, prostates, ect. Phenomenal for your little old ladies with broken hips as they are extremely hemodynamically stable with the isobaric formulation (long as no AS hiding around). 2.5 cc of 0.5% with 10 mcg Sufent or 15mcg Fent = 2.5+ hrs of block. 3 cc with narcotic 3-3.5hr +.

For some basic papers looking at duration and hemodynamic effects a quick medline search pulls up:
http://www.anesthesiology.org/pt/re...lj7NGrpJb2fJJvyn!2092430889!181195628!8091!-1

Also I am assuming your dilution question is do we dilute the 0.5% with CSF?
Answer is no. No difference in level of block or duration but slows onset time.
http://www.blackwell-synergy.com/do...44.1995.tb05863.x?cookieSet=1&journalCode=ana

The effect of cerebrospinal fluid dilution of isobaric 0.5% bupivacaine used for spinal anaesthesia
Summary
A prospective study was conducted to see the effect on spinal anaesthesia of the dilution of isobaric 0.5% bupivacaine with cerebrospinal fluid. Sixty patients were randomly allocated to three groups. In group 1, patients received 3 ml isobaric 0.5% bupivacaine intrathecally without aspirating cerebrospinal fluid. In groups 2 and 3, cerebrospinal fluid 1 ml and 2 ml was aspirated respectively and mixed with 3 ml isobaric 0.5% bupivacaine. A total volume of 4 ml in group 2 and 5 ml in group 3 was administered. Thus, the volume of cerebrospinal fluid remained unchanged. Pinprick analgesia and motor block was evaluated from induction until recovery. No differences in onset time, duration and‘two segments regression’ were noticed. The only statistical difference was the time to reach complete motor block, which was shorter in group I as compared to groups 2 and 3 (6.9 SD 1.4 min versus 11.3 SD 3.0 and 13.5 SD 3.9 min respectively). The mean value of maximum decrease in systolic blood pressure was small, being less than 15% of the pre-operative value for each group. In conclusion, the effect of diluting isobaric 0.5% bupivacaine with cerebrospinal fluid, 1 ml and 2 ml, is minimal and it is an unnecessary procedure with limited clinical effect.
 
CanGas said:
http://www.rxlist.com/cgi/generic/bupivacaine_ids.htm

Just grab the 0.5% single use, preservative free vials from OBS or your epidural cart. Good enough for Epidural = good enough for spinals in most of the world.

Marcaine (bupivicaine) 0.5% is beautiful for longer hips, knees, prostates, ect. Phenomenal for your little old ladies with broken hips as they are extremely hemodynamically stable with the isobaric formulation (long as no AS hiding around). 2.5 cc of 0.5% with 10 mcg Sufent or 15mcg Fent = 2.5+ hrs of block. 3 cc with narcotic 3-3.5hr +.

For some basic papers looking at duration and hemodynamic effects a quick medline search pulls up:
http://www.anesthesiology.org/pt/re...lj7NGrpJb2fJJvyn!2092430889!181195628!8091!-1

Also I am assuming your dilution question is do we dilute the 0.5% with CSF?
Answer is no. No difference in level of block or duration but slows onset time.
http://www.blackwell-synergy.com/do...44.1995.tb05863.x?cookieSet=1&journalCode=ana

The effect of cerebrospinal fluid dilution of isobaric 0.5% bupivacaine used for spinal anaesthesia
Summary
A prospective study was conducted to see the effect on spinal anaesthesia of the dilution of isobaric 0.5% bupivacaine with cerebrospinal fluid. Sixty patients were randomly allocated to three groups. In group 1, patients received 3 ml isobaric 0.5% bupivacaine intrathecally without aspirating cerebrospinal fluid. In groups 2 and 3, cerebrospinal fluid 1 ml and 2 ml was aspirated respectively and mixed with 3 ml isobaric 0.5% bupivacaine. A total volume of 4 ml in group 2 and 5 ml in group 3 was administered. Thus, the volume of cerebrospinal fluid remained unchanged. Pinprick analgesia and motor block was evaluated from induction until recovery. No differences in onset time, duration and‘two segments regression’ were noticed. The only statistical difference was the time to reach complete motor block, which was shorter in group I as compared to groups 2 and 3 (6.9 SD 1.4 min versus 11.3 SD 3.0 and 13.5 SD 3.9 min respectively). The mean value of maximum decrease in systolic blood pressure was small, being less than 15% of the pre-operative value for each group. In conclusion, the effect of diluting isobaric 0.5% bupivacaine with cerebrospinal fluid, 1 ml and 2 ml, is minimal and it is an unnecessary procedure with limited clinical effect.
Click to expand...

What about this in the drug information from astrazenica?
"SOLUTIONS OF SENSORCAINE (BUPIVACAINE HYDROCHLORIDE) SHOULD NOT BE USED FOR THE PRODUCTION OF SPINAL ANESTHESIA (SUBARACHNOID BLOCK) BECAUSE OF INSUFFICIENT DATA TO SUPPORT SUCH USE. "

They also put in bold on the bottle "do not use for spinal." Are people using it for spinals anyway? I realize its persevative free and can't find any problem with it, but in the event you had a lawsuit associated with a spinal you would get dinged for this.
 
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we did an isobaric spinal for a young woman 32 wks pregnant with a femur fracture last night on call. there was no way she was going to tolerate lying in the lateral position with the fx leg down, so we flipped it up, 12.5 mg of isobaric bupivicaine 0.5%, proceed with the ORIF. patient asked to see her leg while they were prepping and bending it in unnatural positions - "oh that's gross" was the reaction, and she tolerated the entire procedure without a touch of pain.
 
bigeyedfish said:
Is anyone doing isobaric spinals? What are you using for your solution? Are you mixing it or is it a prepared solution? As far as I can tell in the US 0.5% and .25% bupivacaine aren't approved for spinal, even if they're preservative free.

I have an attending who's used to using isobaric (he's from out of the country) and he's hounding me to find him an isobaric solution.
Click to expand...

All the 0.5% we have says "not for spinal" on it. We still do. 2.5cc with 25ucg fentanyl should do the trick. 3cc for longer cases. +/- epi if you like.
 
dr doze said:
tetracaine is also a nice isobaric spinal, if you are concerned about the medical/legal implications of using a drug"not approved for spinal" take the 1% solution (10-16 mg) and add a dash of CSF one caveat, blocks can last 4-5 hours without epi. I have not used the lyophilized crystals.
Click to expand...

I have used the crystals and I mix it with D10 (not isobaric) 1cc. It last 3-5 hrs. Best I can remember.
 
I push 0.25% bupivicaine into CSE's all the time.

Actually, what I now routinely do and really like is to draw-up 8mL of 0.25% and 100mcg of fentanyl and put it on the tray. This gives you 10mL of 0.2% bupivicaine and 10mcg/mL fentanyl solution. You do your CSE, and when you put the spinal needle in, you inject 1 mL of this solution directly into the CSF. The patient immediately gets comfortable. You then thread the epidural catheter and "top up" with the 9 mL of the rest of the solution. Works like a charm for someone who is late in labor, fully dilated, and ready to push the baby out. Have done this several times and not even had to start an infusion.

-copro
 
Thanks for the replies. It's interesting to see the variety of recipies. I figured people were using the 0.5 and 0.25% solutions, but my staff are paranoid due to the labeling.
 
coprolalia said:
I push 0.25% bupivicaine into CSE's all the time.

Actually, what I now routinely do and really like is to draw-up 8mL of 0.25% and 100mcg of fentanyl and put it on the tray. This gives you 10mL of 0.2% bupivicaine and 10mcg/mL fentanyl solution. You do your CSE, and when you put the spinal needle in, you inject 1 mL of this solution directly into the CSF. The patient immediately gets comfortable. You then thread the epidural catheter and "top up" with the 9 mL of the rest of the solution. Works like a charm for someone who is late in labor, fully dilated, and ready to push the baby out. Have done this several times and not even had to start an infusion.

-copro
Click to expand...

Do you really need the top up epidural dose if they are about to push anyway? The intrathecal dose will last 1 - 1.5 hrs. I like your technique though for laboring pts that are going to need the epidural after the IT dose wears off.
 
bigeyedfish said:
Is anyone doing isobaric spinals? What are you using for your solution? Are you mixing it or is it a prepared solution? As far as I can tell in the US 0.5% and .25% bupivacaine aren't approved for spinal, even if they're preservative free.

I have an attending who's used to using isobaric (he's from out of the country) and he's hounding me to find him an isobaric solution.
Click to expand...

Recently read a few articles on the so called "isobaric" LA.The plain bupivacaine 0.25% or .5% that we usually use for epidural is physically hypobaric and not isobaric.There are no commercially available isobaric solutions.
 
serenity said:
Recently read a few articles on the so called "isobaric" LA.The plain bupivacaine 0.25% or .5% that we usually use for epidural is physically hypobaric and not isobaric.There are no commercially available isobaric solutions.
Click to expand...


We place a lot of bupivacaine spinals using the .5% solution for knees and such. Though I frequently hear it referred to as isobaric, we typically put the pt. in tburg after the spinal goes in. We do add some fentanyl and epi to the mix however. Not sure about the epi but I have always thought that the fentanyl made things a little more on the hypobaric side.
 
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Noyac said:
Do you really need the top up epidural dose if they are about to push anyway? The intrathecal dose will last 1 - 1.5 hrs. I like your technique though for laboring pts that are going to need the epidural after the IT dose wears off.
Click to expand...

We get a fair amount of calls for epidurals in women who are nearly complete and writhing on the beds. Usually they didn't want an epidural initially but realized they were in agony at 10 cm and refuse to push. I usually place a CSE w/1.75 mg bup and some fentanyl and find that they are able to deliver off that low dose though sometimes I will add a couple cc's of 1/4% to the SAB as well.
 
Noyac said:
Do you really need the top up epidural dose if they are about to push anyway? The intrathecal dose will last 1 - 1.5 hrs. I like your technique though for laboring pts that are going to need the epidural after the IT dose wears off.
Click to expand...

Probably do not need the top-up epidural dose. But, the attending who showed this to me (PP dude) liked it, and never had a BP or HR drop with it. In fact, I did this technique for another laboring patient with a separate attending at my home institution and he asked me why I was doing the top up (actually strongly suggested that I don't do it, but allowed me to show him "my" technique, which I thought was pretty damn cool for an academic attending). I told him, just like you say, that I agreed it was probably redundant, but gave a really good prolonged block for late labor and that where I'd done it at another place I had a couple of women go through second stage without any other meds.

I later heard that he was teaching it to other residents. ;)

When I'm coming up with my gameplan, I only suggest we do CSE's when they present REALLY late.

-copro
 
coprolalia said:
Probably do not need the top-up epidural dose. But, the attending who showed this to me (PP dude) liked it, and never had a BP or HR drop with it. In fact, I did this technique for another laboring patient with a separate attending at my home institution and he asked me why I was doing the top up (actually strongly suggested that I don't do it, but allowed me to show him "my" technique, which I thought was pretty damn cool for an academic attending). I told him, just like you say, that I agreed it was probably redundant, but gave a really good prolonged block for late labor and that where I'd done it at another place I had a couple of women go through second stage without any other meds.

I later heard that he was teaching it to other residents. ;)

When I'm coming up with my gameplan, I only suggest we do CSE's when they present REALLY late.

-copro
Click to expand...

Completely circumstantial. How in the world could this technique prevent the typical side effects that every other labor epidural technique sees from time to time?
 
Noyac said:
Completely circumstantial. How in the world could this technique prevent the typical side effects that every other labor epidural technique sees from time to time?
Click to expand...

Well, I didn't mean to suggest and I don't believe that I directly implied that this prevents hypotension (and sorry if you got that impression). But, actually you'd think it'd happen every time with this technique. I just haven't seen it. Also, all of our laboring patients get a 1-2L bolus of warm IVF pretty much as soon as they hit the door and well before the epidural is placed, even the late presenters.

And, I clearly recognize that this is anecdotal (which I believe was the word you were looking for). The producers are not responsible for the content of the program. These techniques should not be tried by anyone. Not even me.

-copro
 
does it matter if you sit or lay pts down after an isobaric spinal?? how does positioning effect hemodynamics and block destribution?
 
saratoga733 said:
does it matter if you sit or lay pts down after an isobaric spinal?? how does positioning effect hemodynamics and block destribution?
Click to expand...
In my experience if you lay them down too quickly you'll get a higher block maybe because of CSF movement which doesn't happen if you wait 30 sec and lay them down slowly
 
serenity said:
Recently read a few articles on the so called "isobaric" LA.The plain bupivacaine 0.25% or .5% that we usually use for epidural is physically hypobaric and not isobaric.There are no commercially available isobaric solutions.
Click to expand...

Interesting. Can you link those?
 
We do very few, if any, hyperbaric spinals anymore. We do isobaric 0.5% or 0.75% Bupivacaine for everything from RRPs to total hips and knees. When we want a 5-6 mg bupiv dose for a quick little knee scope, we use 0.5% because it is easier to draw up the exact dose.

If we want a "quadrant" block to one leg, then we use hyperbaric.

IIRC, there is a bell curve to CSF baricity, so that in 4-10% of pts, isobaric spinals act as if they are hypobaric.

Also, I cannot remember the last Lidocaine spinal around here. Maybe ten years since the last one. Probably due to the transient radicular pain problem that has been associated with lidocaine spinals.
 
Planktonmd,

I had originally typed 0.05% when I meant 0.5%, I could have sworn that I corrected that before I posted, but apparently not. Sorry for the confusion.
 
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