Clinical Case 088: Putting the art into arterial lines

  Today’s case come from Dr James Wright [NHS RMO refugee in Broome ED]   Arterial lines are a common procedure – can we do it better?

A 35 yr old lady presents to the emergency department with a worsening four day history of pyrexia, malaise, nausea and lethargy.

She is usually fit and well.  No significant past medical history.  No current medications or allergies

Triage observations:

HR = 138,  BP = 112/76   RR =  34    Sats 97 % in room air     Temp 40.8

Despite a septic screen, we were unable to identify a firm source for her fever.

She was appropriately resuscitated:

–       Bloods and Cultures (sputum, blood, urine)

–       Empirical broad spectrum Antibiotics

–       Intravenous fluid loading

After initial resuscitation with adequate fluids (confirmed by IVC collapsibility and Lung field Ultrasound) the patient remained haemodynamically unstable.

Her observations 1 hour in to resuscitation were:

HR = 126   BP = 84/58    RR = 32    Sats = 97    Temp  = 39.6

I am a PGY4 Doctor in Broome ED and the above case was my patient. The ongoing patient care was jointly managed by myself and Dr Parker and we both agreed that the patient was a HDU candidate and required an arterial Line. It was at this point we reached the discussion point of this article:

Arterial lines; Palpation approach vs Ultrasound guidance

Ultrasound is frequently utilised in emergency departments worldwide to perform multiple tasks. However is it needed for simple radial arterial line insertion?  As you all know Dr Parker is an US tragic!

The technique that we were all taught at medical school was simple palpation of the radial artery guiding your stab with a needle.

This is simple, efficient and the majority of times effective.

My first thoughts about the ultrasound guidance technique put to me by Dr Parker were that it seemed to be a little excessive, cumbersome, and time consuming.

We progressed to the procedure which I performed.

I went with the old trusted palpation technique without local anaesthetic and unfortunately failed causing some discomfort to the patient.

Dr Parker’s advice:  “stick with it but try USS guidance and a generous helping of local anaesthetic.”

I was successful and my opinion was completely changed!

I am fairly inexperienced with ultrasound but in-fact found this technique is easy and not at all time consuming to perform. Additionally because it was not dependant on palpation I could inject more local in to the area, therefore making the procedure almost painless.

A study analysing ultrasound-guided and palpation placed radial arterial catheters carried out by Shiver et al found that US guidance for arterial cannulation was the better technique.

There was also a review of RCTs involving US for arterial lines in CHEST 2011 by Shiloh et al.

Their results specifically found that Ultrasound guidance had:

–       shorter time required for arterial line placement (107 vs. 314 seconds)

–       fewer placement attempts (1.2 vs. 2.2 )

–       fewer sites required for successful line placement (1.1 vs. 1.6)

We shouldn’t just look at success rates;

With any procedure there are potential complications, those relevant to this are: vasospasm, haematoma, thrombosis and oedema.

Ultrasound guidance appears to result in fewer placement attempts and therefore fewer complication rates, so shouldn’t its use be implemented regularly and in-fact taught rather than the old palpation technique?!

This is further supported by routine practise for the similar central venous cannulation task. Current practise clearly favours Ultrasound guidance due to its higher efficacy and lower complication rates, so shouldn’t placement of radial arterial catheters too?

Have you thought about using Ultrasound guidance?

Would you use it as a first line measure?

Would you use this technique preferentially in awake patients?  i.e.: does US-guidance allow you to use liberal local anaesthesia and make the procedure less distressing?

Want to see it in action – check out the Microcast from the Ultrasound Podcast on Art line placement

I have not yet used ultrasound guidance enough to make it my routine practise and therefore if a patient has a strongly palpable radial pulse I think I would still attempt the palpation technique initially.

However I would certainly utilise Ultrasound guidance for any subsequent attempts or where the patient has a weakly palpable pulse.

Thoughts?   James


  1. Jonathan Ramachenderan says

    Thanks James. Love your work.

    Working primarily now in theatres, I place most of my lines under ultrasound guidance.

    I used to practice on my intubated ICU patients during the night shift, a lone dark figure, face illuminated by the US screen.

    It has become my first line measure but it is operator dependant!

    With your patient’s falling BP, often a sniff of metaraminol (0.5-1mg) can increase your chance of success!

    • Thanks JR
      I find that I can get the lines in those really hypotensive patients using US without having to use the old Aramine trick.

      also – I reckon using US allows us to identify the nice straight part of any given vessel. I like to use the probe in plane so I can keep a view of the vessel and the wire feeding up the lumen.

  2. I love US guidance, but in general I prefer a classic Seldinger technique (rather than the integral wire cannulas, or a standard cannulation technique) and that really requires three hands (I haven’t found a way to do Seldinger without using both hands yet).

    • I use a kit that has premounted wire that slides with a little tab. You can do it with one hand a bit like sliding an IV off with your finger tip

      • That’s what I meant by integral-wire cannulas, but I find I have less feel for the amount of resistance than with a classic Seldinger.

        The other thing I like about Ultrasound is that it lets you go a bit more proximal, so you’re not taping directly over the wrist joint itself.

      • Ok, I’ve changed my mind. The new technique across the last year is Arrow Quickflash integral-wire cannula, and longitudinal ultrasound. you can see the wire bouncing as a sine wave off the wall of the artery. Will need to get my intern to capture a video on the US the next one I do.

  3. Tony Wong says

    Thanks for the post and useful tips guys. Do you find a problem with arterial spasm when feeding the wire, and hence do you use LA as a routine even if the patient is asleep? Or is this not so much of a problem with ultrasound as you see the needle enter directly into the lumen?

    • Hi Tony
      No. I’ve not seen arterial spasm with wire in.
      I am suspicious that this entity is a myth. Cannot prove it – but using colour Doppler the flow stays whenever I needle an artery.
      Does the vessel spasm? Or did we just like to say that to ourselves if we missed twice in one place?
      Of course if you use USs then you can check the vessel before a second attempt

  4. However do NOT trust your iPad! Re-posted with typos removed!

    I would definitely use local. Some fear that it makes landmark technique harder …. Inject a small bleb then firmly massage it in … Landmarks are preserved and patient happy.

    I might drag out USS for a tricky one. But not as a routine.

    Yep, I know USS is brilliant and Casey uses it to tie his shoelaces, but I wonder what happens when USS is not available?

    Its a bit like ALWAYS using USS for central lines. Or VL vs DL….

    …neat stuff, but i the tech fail ,or is not available, you need to be able to perform the technique using landmarks.

    But trust me on the local.

    • Ah nice analogy Tim
      Of course we do use local +++ when doing awake intubation

      I think I use more generous local when US available. Not a skin bleb, but try to numb the deeper bits too
      The technique remains the same so I don’t think we will deskill too much as we palpate then scan. Point taken though
      I converted to US late in career -so happy to swing both ways
      Tougher if you are starting out

  5. Similar debate over on Doctors.Net.Uk this week, with equally polarised opinions between novices, intermediates and experts

    GENEROUS dollop of LA then massage for a minute – it will dissipate and you will still palpate anatomy OK

    Should we be transducing in rural environs? Too much risk of infection, inadvertent drug administration? What’s correlation of NIBP and IABP?

    Meanwhile, does anyone still do Allen’s test? I don;t. Defensible?

  6. If your struggling to get a radial arterial line in a hypotensive patient, what are your thoughts about a brachial line? Several people have told me that they have a high complication rate but from a quick scan of the literature I don’t think that’s true. And they’re dead easy to place under ultrasound guidance

    • Hi Toby
      good question…
      not a lot of prospective quality data on the radial vs brachial artery cannulation.
      My guess is it is probably like CVCs for infection…. not enough badness to make a really clinically relevant difference
      I found this review
      only 2 permanent iscemic events in each site at a rate of < 1: 1000, so hard to detect without a really big study casey

  7. Interesting piece – thanks James and Casey.

    Of course, the point is moot if your hospital doesn’t have an ultrasound available, as was the case in one hospital I worked recently…

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