Isobaric VS hyperbaric
Started by epidural man
I think iso doesn't spread as far cephalad so you get less sympathetctomy. Traditionally we've done iso bupi for our hips and knees which provide a T6-10 down block at 12-15 mg. For our C-section we do hyperbaric bupi which often go to T4.
Big question is are u laying the patient down right away?
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deleted162650
Yes definitely. The degree of hypotension is less, but more significant is the onset time. Hyperbaric drops the BP fast. Iso is faaaaaar more gradual, easier to manage, and better tolerated (even if the end result is a similar degree of hypotension).
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Isobaric gives me a more even bp over time. But why does the vial say not for spinal use?
Arch Guillotti
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Not specifically FDA approved but everyone uses it anyway.
I think also because it comes in 10-30ml vials and they do not want people accidently drawing up the whole thing and giving too much intrathecally.
In this age of same-day outpatient joints, this is a negative. A spinal lasting a long time for a joint is a bad thing.
I use hyperbaric because it comes in the kit and iso vs hyper doesn’t make a lick of longterm difference in 99% of patients.
If using hyperbaric, people usually keep patient sitting up for a couple minutes? Lay them with the operative side down first? Just curious what people's approaches are.
I use hyper and lay them flat quickly and for a minute or two before rolling lateral (in the case of hips).
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I do plenty of spinals on old hip fracture patients that do great with isobaric. They will be lucky to get discharged to a SNF on POD #2 or 3, certainly not going home same day. I usually go with mepivacaine for same day joints as I find it wears off reliably faster than hyperbaric bupivacaine.
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deleted162650
What dose do you use, and what duration are you seeing (reliable surgical anesthetic duration)?
Any reports of TNS? Literature says similar incidence to lido.
usually 2 mls of 2% will get you 75-90 minutes of surgical anesthesia
I am now more likely to use a bupi vial from our pyxis than the one in the spinal kit. I have had few too many failed spinals from the kit ones that I don't feel like gambling every time, especially if it's C\S patient.
Also, can you use less hyperbaric bupi if you are positioning with a goal of one sided spinal? Or would you still use same dose\volume?
Also, can you use less hyperbaric bupi if you are positioning with a goal of one sided spinal? Or would you still use same dose\volume?
Same here. Not using the kit bupiv unless I have no choice..
Yeah I know that, but chemically there is no preservative in those vials. Must be some other asinine reason why the fda can’t approve it.
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deleted126335
Because Bupivacaine is generic, nobody ever did or is willing to pay for the studies and jump through the hoops to show the FDA that the isobaric version is safe.
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Just use a smaller dose. For outpatient tka...we use 5-8mg of opiod free isobaric. No issues with pacu discharge. We use thr larger doses for revisions. A 15mg isobaric can get me 5-7 hours worth of spinal
I thought that there were more cases of failure with doses below 7.5. I like to use 10 mg but it does give around 3 hours.
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deleted59964
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Absolutely.
If I used mepivacaine for total joints I'd have to sit them up once or twice mid-procedure to redo the spinal. Yay academic joint days.
Practically nothing has FDA approval for intrathecal use. IIRC only three drugs actually have formal approval - morphine, baclofen, and something else no one uses.
That's the one, ziconotide.
I use isobaric for all hips/knees. Pretty much 15 mg + 25 mcg fentanyl is my cocktail for all in both situations regardless of patient size, I haven't noticed much of a difference between patients in terms of it changing the course of their care. What is very noticeable is how gradual / nonexistent the subsequent hypotension is compared to hyperbaric. I've given 20 mg isobaric for a 4+ hour case a couple times, still essentially no issues with BP.
Sometimes they will still be able to wiggle their toes at time of incision, seems to still work just fine. Propofol will keep them still.
In terms of laterality, I have no evidence that this makes a difference but just because it makes me feel like I'm being thoughtful about it, I will angle the hole of the whitacre needle to the operative side slightly so that the meds will shoot UP and OVER to the operative side preferentially. I don't care about patient positioning, we just lay them down and go. Again, don't know if it makes a difference, it's not evidence based beyond my anecdotal experience.
Sometimes they will still be able to wiggle their toes at time of incision, seems to still work just fine. Propofol will keep them still.
In terms of laterality, I have no evidence that this makes a difference but just because it makes me feel like I'm being thoughtful about it, I will angle the hole of the whitacre needle to the operative side slightly so that the meds will shoot UP and OVER to the operative side preferentially. I don't care about patient positioning, we just lay them down and go. Again, don't know if it makes a difference, it's not evidence based beyond my anecdotal experience.
with faster surgeons we use 3% chloroprocaine 1.3-1.6ml range gets about 70-80 mins. if they are slightly slower we go mepivicaine 2% around 2-2.2ml and reliably get around 80-90mins. Thousands of joints a year doing these same days and not a single incidence of TNS.
We have used 5 cc of 1% chloroprocaine spinals for cases about 1 hr long.
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That's at least 15min too long
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deleted162650
Our guys definitely aren’t fast enough for CP. I doubt they’re fast enough for Mepi either, but one of them has been bugging us to try it for same day totals. Our current recipe is 7.5mg isobaric bupi no opioids.
You're talking 15 mg iso bupi, right? Which is like double dose compare to what other people use for hips/knees...
That’s some good chloroprocaine right there. I’ve used 2cc of 3% for a 70-80min total knee and they are in pain immediately in the PACU. I use 40-45mg of mepivacaine regularly depending on surgeon and type of joint and really like it’s ability for quick resolution at the surgery center. Perfect compromise between chloroprocaine and bupivacaine.
Lucky! Our surgeons take 3 hours or more. Academics.
yea mepi is great too, I don't see too much benefit of using chloro over mepi but for me personally Ive had more seemingly failed spinals (inadequate block) with mepivicaine for some reason.
Our surgeons aren't fast, patients stay overnight in the inpatient setting. Typically 2 hour hips/knees, sometimes longer. I haven't really had to think any harder about throughput. Until we get a fast joint guy that challenges the current paradigm, it's 3 cc 0.5% bupi for all and everyone is happy!
Some of our surgeons need CSE because 15 mg of bupi isn't enough
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deleted87051
I've done that in residency a few times
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Tetracaine + epi
Yeah we do all epidural for one surgeon hips
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deleted126335
Single shot phenol is simpler and gets it done.
You guys have very fast surgeons. In any case, I am using isobaric Ropivacaine. Generally 2.5ml for joints. We have had one or two outliers with a long duration but for most, the spinal wearing off is not the rate limiting step in their discharge.
isobaric more stable. use on anyone adult. even the 100 yr olds
also nto sure why so many spinals fail...
also nto sure why so many spinals fail...
What do you mean by so many? I think I've had one spinal fail.
Saw a few spinals that just doesn't work at all. Despite great csf and technically easy
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