Ultrasound for Epidurals… I ask an expert: Dr Mitch

I have had a few readers ask questions about the use of ultrasound for the difficult epidural – usually in the labour ward context, but we sometimes run into this in the OT for combined spinal-epidural blocks.  Now I  love all things ultrasound – but looking at the literature it is tough to get a read on the utility of US in the often troublesome area of epidurals.  All those bones – can we see anything useful?  So I have asked an expert, and gotten a few handy, practical pointers.

Dr Chris Mitchell is a Consultant Anaesthestist at King Edward  Memorial Hospital for Women in Perth, Western Australia. But Mitch is more than an Anaesthetist – before he went into specialist training Chris was a rural GP-Anaesthetist in NW WA.  In fact my first job after my training in Anaesthesia I actually replaced Chris!

Now onto the meat of the post – here are Chris’s tips in beautifully illustrated form – click here [US for Epidurals]

I think it should be said – epidurals in the labour ward are an elective procedure.  There is a risk : benefit pay off.  If you are increasing the risk side of the equation as a result of a difficult insertion, then you need to discuss that with the patient – so before calling for he US machine I think it is worth a pause to consider if this is worth a try – I am sure that for the occasional operator this technique wil help, but is no magic bullet!

We usually try and avoid the patients with really tough anatomy – if the BMI is over 35 we usually start to strongly consider referral to a larger institution for a whole raft of safety reasons.

Huge thanks to Dr Mitch for his pearls on epidurals and US.  I would love to hear your experiences and if you have any questions for Chris I will pass them along.  Comments please




  1. minh le cong says

    thanks guys! thats a very good resource , not just for epidurals!

  2. Very useful, and gives us a guide to practice (my wife is just about to get covered in ultrasound gel, but she doesn’t know that yet)

    So my approach will be

    (i) plan A – standard epidural

    if difficult anatomy, then

    (ii) plan B – use USS to help identify where to go…

    (iii) plan C – consider remi PCA as an alternative

    But I agree with Casey – if you can see these patients in pre-admission clinic and perhaps stave off having to tackle difficult anatomy at 3am in a labouring primip, then so much the better

  3. Just re-posting with my EM blog listed as my website…
    In term of US for LPs: I use them regularly to estimate depth and confirm anatomy in my more rotund LP punters. Did two epidurals with the same approach about 18 months ago during an anaesthetics rotation. Works well.

  4. toby thomas says

    “A Chinese research group has developed a single crystal ultrasound transducer and put it on the end of a stylet fitting inside a standard epidural needle. The ultrasound probe will let you visualise where the tip of the needle is when placing the epidural. With A-mode ultrasound, you’ll see the ligamentum flavum and dura mater approaching. It’s not for clinical use just yet, but a fascinating technology”

  5. Yeah, that is neat.

  6. Gareth Taverner says

    The 3am phone call to labour ward to site an epidural…..
    This lady had atrocious scoliosis! And there is no plan B.
    I’m in the unfortunatel position of being the only epidural competent doctor for 200kms.

    Fortunately I had been shown the tricks by Chris Mitchell a few months before and I mapped the spine with the ultrasound machine and hit the space first pass instead of poking around painfully.

    Thanks Chris! Your technique saved me much angst and the lady much pain and a perforated dura and headache!

  7. Power of #FOAMed

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