03 September 2008

Post-LP Headaches

When you come to the ER with certain complaints, most commonly an acute or very severe headache, it's normal for the ER doctor to do a spinal tap. This allows us to rule out serious causes of the headache, typically meningitis, subarachnoid hemorrhage, and occasionally pseudotumor cerebri, but obtaining and analyzing a sample of spinal fluid. However, one known risk of performing a spinal tap, or lumbar puncture (LP), is that the needle hole will not properly seal, and a spinal leak will develop. Unfortunately, this results in a headache which is often worse than the original headache!

In this business, it seems that things come in clusters, or at least those are the things you notice. I have noticed a large number of patients coming in with post-LP headaches. This is not only uncomfortable and a hassle for the patient, but it's a hassle for us, too, since we have to get anesthesiology to come down for a "blood patch" to stop the leak, and that throws a crimp into everybody's schedule.

Our ER docs have always done LP's with a 22-gauge "Quincke" needle -- it's a beveled, hollow-bore needle, and the standard needle in our LP kit. I've read that use of a "Whitacre" needle, which is needle-pointed and side-bored can be less traumatic and have a lower incidence of the post-LP headache.












I've tried to use a Whitacre a few times, though, and found it to be a terrible pain in the butt, or at least there seems to be a steep learning curve. The needles are thinner and more bendy, and the blunt tip makes it a lot harder to penetrate the thick, fibrous ligaments of the spinal column. Of the half-dozen tries I've made with the Whitacre, I've maybe been successful twice, had to bail and switch to a Quincke twice, and totally failed twice. (My success rate with LPs in general is well over 90%, so this is quite unusual for me.)

Anyone out there have much experience with this needle? Are they as great as they are made out to be in terms of the low complication rate? Are there any tricks or tips to make it work better? I've heard about using an 18-gauge "introducer" needle, but that seems a bit dodgy to me. I'm going to give it a few more goes to see if I can make it work, but right now I'm not feeling too great about this idea.

4 comments:

  1. I'm used to the kits that we use for spinals. They come with a Quinke, but I add a 25 G pencil point needle. I do use the 18G introducer, the trick to using one is to be careful how far you stick it in. With thin people, I only put it in halfway until the PP needle reaches the hub, then I push them in together.

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  2. Most of my spinals are for intrathecal analgesia during labor, which is administered with the patient seated upright. I use 25G Whitacre needles exclusively. After hundreds of intrathecals, only one spinal headache after mistakenly using a non-Whitacre.

    If you find them too bendy, you might try a larger gauge Whitacre.

    The 18G introducer is not as horrible as you think it would be. After infiltrating, I insert the introducer--usually up to the hub in pregnant women, then the Whitacre. Works well.

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  3. I've never used any needle other than the standard 20 G Quinke with a stylet (except for pedi pts I use a 22 G), and I've never knowingly given anyone a spinal headache. Of course I rarely get any followup, but that's one of the best things about the ER.

    Just get the CSF and move on to the next task. Why mess around with fancy tricky bendy needles?

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  4. Here in Australia I have always used a 24G bullet tip needle. They can bend, but it usually does not matter because of the introducer. If I struggle (ie-large patient) I use a long 22G bullet tip. A 22G is also a good idea if the indication is for meningitis - 24G takes too long to measure a pressure.
    I have never seen a Quinke - I don't think we even stock them anymore! Here's a good article from the BMJ - there are many more out there

    http://findarticles.com/p/articles/mi_m0999/is_7267_321/ai_66881320

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