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


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