Intrathecal without wet tap?

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linkin06

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Had this happen to me on OB last night. This girl's been laboring all day, and I don't hear anything for an epidural, of course until right at midnight as I lay down my head for 20 minutes. I start flipping though her chart, and she's 21 and I do see things like meth at some point? OB's note only mentions marijuana though, and when I walk in the room she seems relatively normal, not whacked out. But she is screaming and hollering...her positioning is all horrible. She won't really sit still, and she's screaming that she's so tired, she hasn't slept 2 days... I get going, and she's not huge, but her moving and positioning is horrible, I'm feeling weird false losses here and there. I finally get a maybe loss, it's not the smoothest but a noticeable loss with saline. I thread the catheter in, and it goes really easy. But as I get ready to do test dose, I aspirated first, and it just keeps coming back. Now I have 3 cc test dose + 2 cc more. I squirt it all out, aspirate again, and it's definitely coming back clear. And now she says she's got a horrible headache, it's in her neck even. And then she gets nauseous and puking a little. I pull the catheter, go down a level. After she's done puking a little we really reinforce everything, get her sitting cross legged, and she's still whining and complaining a lot, but she's holding better position. I get loss at 7, this one tests fine. I bolus and really watch her closer for first 30 min, and she really calms down to the point her contractions are nothing. Still has headache, so I get a bottle of Tylenol hanging and go lay down again. I have wet tapped before of course, and I know how that free flow is. What happened exactly here? Did I nick the dura and magically threaded it intrathecal? And why such sudden symptoms? Or is she just super sensitive like that?

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Yes- happened to me a few months ago- thin lady, easy LOR, no csf thru Tuohy; threaded catheter, then nothing really upon aspiration of catheter; but after 1-2 cc test dose with lido with epi, clearly intrathecal. When laid her down, re-aspirated catheter, and csf definitely came back this time.

Lesson to take test-dosing seriously. Even if you’re ‘positive’ the catheter isn’t intrathecal due to negative csf aspiration from catheter, or negative csf from Tuohy, you can never be 100% certain…
 
Yes- happened to me a few months ago- thin lady, easy LOR, no csf thru Tuohy; threaded catheter, then nothing really upon aspiration of catheter; but after 1-2 cc test dose with lido with epi, clearly intrathecal. When laid her down, re-aspirated catheter, and csf definitely came back this time.

Lesson to take test-dosing seriously. Even if you’re ‘positive’ the catheter isn’t intrathecal due to negative csf aspiration from catheter, or negative csf from Tuohy, you can never be 100% certain…
Exactly.

Sudden headache can be caused by squirting an air bubble in the subarachnoid space.
 
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I suspect you were tenting the dura with the tuohy and pushed catheter intrathecal when you threaded it. And yes I have seen patients start complaining of pdph symptoms shortly after wet taps
 
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Yes- happened to me a few months ago- thin lady, easy LOR, no csf thru Tuohy; threaded catheter, then nothing really upon aspiration of catheter; but after 1-2 cc test dose with lido with epi, clearly intrathecal. When laid her down, re-aspirated catheter, and csf definitely came back this time.

Lesson to take test-dosing seriously. Even if you’re ‘positive’ the catheter isn’t intrathecal due to negative csf aspiration from catheter, or negative csf from Tuohy, you can never be 100% certain…
Yea doesn't seem worth chancing something like that. High risk low reward. I also don't want to leave it intrathecally cuz I don't trust the nurses at all.
 
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Were you using a wire reinforced catheter or the stiff plastic Arrow catheter? My old shop had a high rate of intravascular catheters with the stiff plastic ones, switched to the wire reinforced catheters and the problem virtually went away. My current shop only has the stiff plastic Arrow catheters, and I have seen a couple of times recently that those catheters can be bulldozed into just about anything… subarachnoid space included.

I had a similar case not so long ago with a thoracic epidural where it was a textbook placement, nice crisp loss using a continuous technique, and then while threading felt a pop and a give (which in retrospect I assume was the catheter poking through dura). Despite negative aspiration through the catheter, very clearly had a positive test dose (close to a high spinal with 3cc of 1.5% lido at T6-7!) ended up giving some contrast to the catheter just to confirm that it was intrathecal, since aspiration continued to be negative…

Moral of the story is that the floppy wire reinforced catheters will thread into whatever space the tip of the Tuohey needle is in. The stiff plastic catheters well go just about anywhere… I’m not a fan
 
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Had the same thing happen about two years ago. Average bmi (low 30?). Normal loss of resistance, no CSF drip through touhey, thread catheter, aspirate before test dose (maybe aspirated fluid but not definitive, felt normal), and test dose positive for intrathecal. Cracked open the 1.5 cc spinal bupi in a 5 cc syringe to aspirate and saw swirl as additional confirmation. Disconnected spinal bupi and left catheter as intrathecal with dosing at such rate.
I couldn’t and still can’t reconcile it as intrathecal with what I felt. Didn’t use the stuff plastic arrow catheter.
 
Had the same thing happen about two years ago. Average bmi (low 30?). Normal loss of resistance, no CSF drip through touhey, thread catheter, aspirate before test dose (maybe aspirated fluid but not definitive, felt normal), and test dose positive for intrathecal. Cracked open the 1.5 cc spinal bupi in a 5 cc syringe to aspirate and saw swirl as additional confirmation. Disconnected spinal bupi and left catheter as intrathecal with dosing at such rate.
I couldn’t and still can’t reconcile it as intrathecal with what I felt. Didn’t use the stuff plastic arrow catheter.
I know that feeling of frustration, when all signs point to a normal placement, but the test dose clearly indicates intrathecal placing. Tenting of dura, with cath going thru it seems to be the explanation. And initial negative csf aspiration from cath may be due to the end hole(s) being somehow wedged against something, thus occluding csf entrance (but then again the intrathecal space is a sea of csf, so I don’t fully get it…)
 
For those of you who had positive test dose after such a placement and didn’t leave an intrathecal catheter, did you wait until block fully resolved prior to replacing?
 
For those of you who had positive test dose after such a placement and didn’t leave an intrathecal catheter, did you wait until block fully resolved prior to replacing?
I think it should be ok to move to another spot since people do DPE all the time too
 
For those of you who had positive test dose after such a placement and didn’t leave an intrathecal catheter, did you wait until block fully resolved prior to replacing?
Just place it. Wait for the dose to wear off before you start dosing the new one if you want.
 
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I would expect one, especially since she got symptoms during the procedure, but it's not guaranteed. And personally, my threshold for a blood patch would be very low in this lady.

Just inject 20 cc of blood through the catheter before you pull it
 
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Prophylactic blood patches haven’t been shown to be helpful. Wouldn’t recommend doing that.

Perhaps, but if she already has symptoms at the time of catheter removal, then this would be a reasonable option.
 
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Perhaps, but if she already has symptoms at the time of catheter removal, then this would be a reasonable option.

Given the fact that her headache developed at the time of epidural placement after he took ~4 ml of CSF out, do you think that her headache is being caused by a dural puncture at this time?

Edit: sorry I reread this and want to clarify: I thought you were advocating putting blood into the catheter at the time of placement, but you're probably referring to putting blood through the catheter if she develops a PDPH later on down the line. Ignore the above
 
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Given the fact that her headache developed at the time of epidural placement after he took ~4 ml of CSF out, do you think that her headache is being caused by a dural puncture at this time?

Edit: sorry I reread this and want to clarify: I thought you were advocating putting blood into the catheter at the time of placement, but you're probably referring to putting blood through the catheter if she develops a PDPH later on down the line. Ignore the above

That's what I meant but that's not my practice. I do it later if symptoms persist.
 
If you get a wet tap and then switch to a different level and place it, dose it very slowly and with about 50-60% of what you would have otherwise.
Agree with the comments about the stiff plastic catheters. Far more intravascular and intrathecal placements with those.
Also agree about the headache potentially being from the peneumoencephalogram that was likely done. It can be intense, although I have also seen pretty quick onset of PDPH sx.
 
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