Anesthesia question

[clubdeac]

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Ok need some help from all you anesthesiologists out there. 0.25% marcaine is 2.5mg/ml marcaine correct? 2% lido is 20mg/ml lidocaine and so on and so forth, correct. So my question is, how many mg marcaine and lidocaine would it take injected intrathecally in the lumbar spine to cause a complete spinal? A variation of this question would be, could you inadvertently inject 2cc's of 0.25% marcaine intrathecally and not have any significant motor or sensory deficits?

 

[jj337]

To do a spinal for a c-section, you generally use 1.2 to 2 mL of 0.75% bupivicaine (8 -15mg of Bupivicaine) or 1.2 to 1.6 mL of 5% lidocaine (These solutions are hyperbaric so the block stays more caudal).

IMHO, 2 mL of 0.25% Marcaine (5mg) intrathecally generally will cause something. Maybe not a complete spinal but a sympathectomy, numbness, and/or weakness.

 

[BobBarker]

For a CSE many people use .5cc of .25% bupivicaine so a couple of cc's should have immediate, noticeable effect intrathecally.

 

[Jcm800]

To do a spinal for a c-section, you generally use 1.2 to 2 mL of 0.75% bupivicaine (8 -15mg of Bupivicaine) or 1.2 to 1.6 mL of 5% lidocaine (These solutions are hyperbaric so the block stays more caudal).

IMHO, 2 mL of 0.25% Marcaine (5mg) intrathecally generally will cause something. Maybe not a complete spinal but a sympathectomy, numbness, and/or weakness.

i agree. something, but unlikley compete spinal. the volume is higher than what is generally used in C-section, but the pregnancy leads to "higher" levels than in a non-prego.

I have gotten high spinal with 1.8 cc of marcaine 0.75 in pregos that laid down to quick and were huge, but nothing that was a complete spinal...

so i would say something would be noticed for sure, but unlikely complete spinal.

now when accidently put 7 cc of Lidocaine in an "epidural catheter" that really went intrathecal, now that was a mess....

 

[clubdeac]

Ok so the consensus is maybe something?? So a patient saying they have a weak leg with some mild weakness on exam after 2cc's 0.25% could be epidural, could be intrathecal?

 

[lord_jeebus]

How fast was the onset? When I give laboring women 1 ml of 0.25% bupivacaine intrathecally, they notice sensory changes within a minute, weakness soon after that. I can't see 2 ml working so quickly if placed in the epidural space, and even in a sensitive patient it should be quite mild.

 

[bedrock]

How fast was the onset? When I give laboring women 1 ml of 0.25% bupivacaine intrathecally, they notice sensory changes within a minute, weakness soon after that. I can't see 2 ml working so quickly if placed in the epidural space, and even in a sensitive patient it should be quite mild.

Either way, this is why I never inject local once I've reached the epidural space.

 

[clubdeac]

How fast was the onset? When I give laboring women 1 ml of 0.25% bupivacaine intrathecally, they notice sensory changes within a minute, weakness soon after that. I can't see 2 ml working so quickly if placed in the epidural space, and even in a sensitive patient it should be quite mild.

How weak do they get?? This occurred once I got the patient off the table

 

[Jcm800]

How weak do they get?? This occurred once I got the patient off the table

could be pretty weak... How weak and where? bil legs, upper extremities?

i use lido in most of my TFESI in hte lumbar region, and they can get weak with 1-2 ccs for 30 minutes. Happens frequently, and these are epidural injections...

Marcaine, they stay weak for hours, thats the miserable part. I Never use marcaine in ESIs anywhere...

 

[PMR 4 MSK]

I stopped using local in my ESIs when a seemingly dry LESI started having ascending numbness with 2 cc 0.25% bupivicaine. It went to the C6 level. That was 4-5 years ago.

 

[clubdeac]

I stopped using local in my ESIs when a seemingly dry LESI started having ascending numbness with 2 cc 0.25% bupivicaine. It went to the C6 level. That was 4-5 years ago.

What? How does 2cc 0.25% marcaine go to C6?

 

[DOctorJay]

Baricity

Plain bupivacaine, however, is unpredictable in its behavior, often spreading to cervical dermatomal levels (6)

http://m.anesthesia-analgesia.org/content/100/4/1159.long

 

[PMR 4 MSK]

What? How does 2cc 0.25% marcaine go to C6?

Dunno. Hysteria maybe?

 

[epidural man]

So my question is, how many mg marcaine and lidocaine would it take injected intrathecally in the lumbar spine to cause a complete spinal? QUOTE]

Variable and based on many factors.

A variation of this question would be, could you inadvertently inject 2cc's of 0.25% marcaine intrathecally and not have any significant motor or sensory deficits?

I doubt it. This would most likely cause weakness.

However, one thing that is a scary scenario - scary because it gives such weird and unpredictable responses, is a subdural injection of any volume.

 

[epidural man]

Ok so the consensus is maybe something?? So a patient saying they have a weak leg with some mild weakness on exam after 2cc's 0.25% could be epidural, could be intrathecal?

Intrathecal injection is very unlikely to have a unilateral block (again...subdural injection?).

It sounds epidural to me.

Marcaine injections can have very rapid onsets and again depends on many factors, but I have seen it act as fast as any other local. I read a study about using marcaine for skin pre IV injection, and the onset in that study was the same as lidocaine.

 

[epidural man]

Why are you given local for an ESI again? Did we address that issue already?

 

[PinchandBurn]

Why are you given local for an ESI again? Did we address that issue already?

It's diagnostic. It tells you that you are in the right disc space/level right away. Yes you are injecting steroids, but as you know steroids take many days to work, some get absorbed systemically,etc.

I use local aneshtetic but usually a veyr small amount (1ml) diluated with NS. Additionally, at this small dosage especially when mixed with saline, I doubt one would get a profound weakness. Bupi is generally more sensory.....

 

[lobelsteve]

It's diagnostic. It tells you that you are in the right disc space/level right away. Yes you are injecting steroids, but as you know steroids take many days to work, some get absorbed systemically,etc.

I use local aneshtetic but usually a veyr small amount (1ml) diluated with NS. Additionally, at this small dosage especially when mixed with saline, I doubt one would get a profound weakness. Bupi is generally more sensory.....

My books failed me again. I cannot find literature to support a diagnostic component of local anesthetic in ESI.

That being said- if acute/hot radic- I'll use 2cc 2% lido with the steroid. Criteria is crying from acute pain. Only downside is potential weakness/numbness for an hour.

I do use a ton of local (up to 6cc) from skin to get down to epidural space. If I am deeper than expected when checking the lateral, checking the lateral, checking the lateral, checking the lateral (do you guys check laterals? ) I sometimes get a drop of lido 1% in the canal and have caused reduced sensation in the leg for 15 minutes. Then we keep them for 30 to make sure things are back to normal. Slows down the day a bit.

A lot of folks trained with 4cc lido/bupi and 4cc NSS/steroid for ILESI/CESI. Still within the SOC, just not sharp like low volume NSS/steroid. CESI with high spinal is going to ruin your afternoon schedule.

 

[Algiatrist]

And, if the person stays the whole morning and misses work, you end up buying the medical office they work at lunch.

It's a nice gesture. My fellowship director taught me that. 👍

 

[lobelsteve]

And, if the person stays the whole morning and misses work, you end up buying the medical office they work at lunch.

It's a nice gesture. My fellowship director taught me that. 👍

Nice, but clearly knows not how to run a business, or does he?

Got a spinal? If not ascending and only L spine- you owe the patient chocolate cake. One of the rules in my fellowship training.

 

[epidural man]

It's diagnostic. It tells you that you are in the right disc space/level right away. Yes you are injecting steroids, but as you know steroids take many days to work, some get absorbed systemically,etc.

I use local aneshtetic but usually a veyr small amount (1ml) diluated with NS. Additionally, at this small dosage especially when mixed with saline, I doubt one would get a profound weakness. Bupi is generally more sensory.....

there is no way that is diagnostic.

Even a "selective" nerve root block probably goes everywhere. i don't call them selective anymore, I call them targeted nerve blocks.