Saturday, 12 September 2015

It's OK to ask for an atraumatic needle

Lumbar puncture is an important procedure in the early stages of MS when other causes need to be ruled out. And in the course of MS LP can help establish whether drugs work or not, for example by measuring the level of specific proteins in the cerebro-spinal fluid. The PROXIMUS trial of oxcarbazepine on top of an immunomodulatory drug is an example (and still open for new participants!). 

With good technique and use of a local anaesthetic there is usually very little pain involved in the procedure itself. However, a common problem is so called 'post-lumbar puncture headache syndrome', a dreadful positional headache usually lasting a few days until it spontaneously resolves. The syndrome is due to the small leak of spinal fluid that remains after withdrawing the spinal tap needle. 



Atraumatic (pencil tip, top) and traumatic (cutting) needles
It has been clear for decades that the risk of this syndrome can be significantly reduced by using a non-cutting (atraumatic) instead of the traditional cutting (traumatic) LP needle. Despite numerous studies in favour of atraumatic needles, however, their use remains the exception rather than the norm. 

In this review we explore the reasons for such poor uptake of an evidently useful change in practise. We hypothesize the poor uptake by neurologists of atraumatic needles has virtually nothing to do with the evidence, but all with poor communication among clinicians, between seniors and juniors, commissioners, and people about to undergo an LP not knowing there are alternatives between needle systems used. For anyone about to have an LP we have produced a simple website summarizing the key information.

Atraumatic needles for lumbar puncture: why haven't neurologists changed?
Davis A, Dobson R, Kaninia S, Giovannoni G, Schmierer K.

Diagnostic lumbar puncture is a key procedure in neurology; however, it is commonly complicated by post-lumbar puncture headache. Atraumatic needle systems can dramatically reduce the incidence of this iatrogenic complication. However, only a minority of neurologists use such needles. In this paper, we discuss possible reasons why neurologists have not switched to new technology, looking more at diffusion of innovation rather than lack of evidence. We suggest ways to overcome this failure to adopt change, ranging from local interventions to patient empowerment.

CoI:  This is work by Barts MS.

14 comments:

  1. Our if I knew that when I made my lumbar puncture was made up without anesthetic ... Maybe not use atraumatic needles by "ignorance" same, or better, perhaps indifference ... "Lucky" my I did not have the post puncture headache ... But excuse my ignorance, and out of curiosity, but what would be the proteins found in the cerebrospinal fluid would help much to know whether a drug will work or not?

    ReplyDelete
    Replies
    1. PROXIMUS uses neurofilaments (scaffolding proteins of axons) as outcome index. We know the release of neurofilaments is part and parcel of axonal damage. If the release of neurofilaments can be reduced or stopped, the inference is that fewer axons are being damaged.

      Delete
  2. In 200I had a shock diagnosis & after the 3rs dose of methyl pred. I could fly home and come to terms with the diagnosis , ah but first the lumbar puncture... Next day worst headache EVER. I lay on the sofa thought of death.
    If only I'd known ....

    ReplyDelete
  3. Would you require a LP for a patient that fulfills the 2010 McDonald criteria? Would you undergo it yourself under this assumption?

    ReplyDelete
    Replies
    1. I didn't have an LP, my symptoms and MRI scan were enough to diagnose me with RRMS. Though one of my neurologists tried to encourage me to have the LP, I couldn't face having it done. The LP would of been a tick box exercise but may provide a bit of useful information.

      I think if it was essential I needed a LP I would need to have someone who is experienced in performing LP's.

      Delete
    2. The McDonald criteria are only valid under one key assumption - that there is no better explanation for the symptoms & signs than MS. Examining the spinal fluid early helps a great deal ruling out other condition that have different prognoses and treatment strategies. Yes, I would have an LP, but only with and atraumatic needle in the hands of somebody who has done it before...

      Delete
    3. Like Anon at 10:04pm I also did not have an LP. An MRI was done to rule out MS, querying ischaemic small vessel problems, but several large spinal lesions put paid to that theory apparently, and the neuro said an LP was not needed (for which I was extremely thankful, having heard about some of the very unpleasant after-effects of LPs). Certainly my symptoms and decline in physical capacity in the several years prior to diagnosis, and my post-diagnosis ongoing decline in functioning fit with what I have since learnt about MS.

      Fair enough to do an LP if required to rule out other conditions, but I see no need to subject any patient to unnecessary invasive procedures if it is not essential. My understanding is that an LP for oligoclonal bands is negative in up to 15 or 20% of people with MS anyway. My neurologist did not do any blood tests at all, and I later ended up getting my own B12 tests done just in case that was a cause - especially as I was faced with taking nasty MS medications with potentially nasty side effects (which did eventuate).

      Delete
    4. DrK, still LP seems not to be sensitive os specific enough as a surrogate marker for an MS diagnose, and as others co-sufferers argue, can be quite traumatic. I did not have it done either, despite my neuro's insistance...http://www.ncbi.nlm.nih.gov/m/pubmed/26343922/?i=2&from=/26350555/related

      Delete
    5. Dr K
      From what I understand, LP can neither confirm or rule out MS.
      What can the LP diagnose?
      Meaning, is there some alternative diagnosis that can be confirmed or ruled out by doing an LP?

      Delete
    6. At the onset of MS, a number of differential diagnoses need to be considered. Just as any other test, LP won't confirm or refute MS in isolation. However, numerous other conditions can safely be considered unlikely, or in fact ruled out, by testing the spinal fluid for the presence of a viral (Herpes species) and bacterial (for example, Borreliosis and Listeriosis), or malignant (lymphoma) causes. The rate of people with MS who are persistently negative for oligo-clonal bands is very low at ~5%.

      Delete
  4. Two days after my lumber puncture I was in Westminster Abbey, lighting a candle in the nave, overcome with a crippling headache. I puked all over the place an no-one even came to help me or ask if I was okay.

    People must've thought I was a junkey. That's religion for you.

    ReplyDelete
  5. My center uses pediatric sized needles wherever possible, it is very nice. It is very noticeable when the contrast is injected, takes 3 minutes and is comfortable - no sudden cold feeling.

    ReplyDelete

Please note that all comments are moderated and any personal or marketing-related submissions will not be shown.