Wednesday, June 22, 2011

Ultrasound-Guided Central Venous Catheter Insertion

Despite the large amount of published evidence (here, here, and here) that ultrasound guidance reduces the failure rate of central venous catheterization, especially for cannulation of the internal jugular vein, some physicians still claim that there is no difference between the success rate of ultrasound guidance and the landmark method. This was the subject of a brief discussion regarding the safety of central venous catheter insertion in coagulopathic patients on Twitter. 

I have a couple of anecdotes to share. I was called to insert a line in an obese patient with idiopathic thrombocytopenic purpura (also called immune/autoimmune thrombocytopenic purpura or ITP). The patient’s platelet count was 2,000. Despite the short, bulky neck, a physician assistant (PA) who had done only 20 previous internal jugular sticks, accessed the vein on the first attempt using ultrasound guidance and there were no complications.

We were called to insert a central line in a morbidly obese man (see photos) who was hypotensive. A PA who had done fewer than 10 previous central line insertions successfully cannulated his right internal jugular vein on the first try using ultrasound.

I would not have attempted to cannulate the first patient without ultrasound guidance. The second patient would have probably had a subclavian approach which would have been difficult.

I was skeptical regarding ultrasound for vascular access for years. Now I would not insert a central venous catheter without using it.


Cliff Reid said...

I've been doing central lines since 1993, but only used ultrasound since 2004. I'm with you - I don't do them now without having at least placed the US probe on the patient to confirm the anatomy. The exception for me at the moment is subclavian lines, which I don't routinely US.


precordialthump said...

I'm exactly the same as Cliff Reid - but less experienced, less knowledgeable, and less English (only half!).
However, if we're talking about evidence base, for predicted 'easy' ultrasound I would probably have to concede that there seems to be little evidence that US is beneficial (is there anything new that invalidates the conclusion of this 2004 BestBETs review?: Nevertheless, I will always at least look with the probe if its available - human bodies rarely read textbooks, so landmarks are only so helpful, and sometimes the size of vessels can be ridiculously different between right and left.
Chris Nickson

Skeptical Scalpel said...

The Best Bets paper you mentioned states the following:

“In patients with a potentially difficult central line insertion, the Ultrasound technique reduces complications and time to insertion. However in those patients where no difficulty is predicted, there is no evidence that the ultrasound technique confers any advantage.” My comment is that one must become facile with the ultrasound technique on the less difficult cases. Then the tough ones won’t be so tough.

Here are two other references:

Current Concepts: Preventing Complications of Central Venous Catheterization.
McGee, David C.; Gould, Michael K. New England Journal of Medicine. 2003;348:1123-1133

“In hospitals where ultrasound equipment is available and physicians have adequate training, the use of ultrasound guidance should be routinely considered for cases in which internal jugular venous catheterization will be attempted.”

Real-Time Ultrasonographically-Guided Internal Jugular Vein Catheterization in the Emergency Department Increases Success Rates and Reduces Complications: A Randomized, Prospective Study. Leung, Julie MBBS, BSc; Duffy, Martin MBBS; Finckh, Andrew MBBS, BA. Annals of Emergency Medicine. 2006;48:540-547

“Conclusion: Ultrasonographically guided internal jugular vein catheterization in the ED setting was associated with a higher successful insertion rate and a lower complications rate.”

Takeokun said...

The research on the utility of US guidance for central venous access at the IJ is a little sparse recently. This is because of a lot of the data shows that it has reduced mechanical complications, reduced failures rates, and improved first pass success.

The problem in using success as your clinical end point is that we are not good at giving up. Eventually the line will be done but the cartoid may have been tagged a few times or there is a large hematoma.

Combining the data from multiple studies have led to the reccommendations from the AHRQ, CDC, CMS (all US) and NICE (UK) that US be used in realtime for IJ placement.

Even the American College of Surgeons have agreed in their update.

The most recent was from teh CDC that reccommended the use of US to prevent multiple passes to help prevent CLABSI.

However, all of these reviews are predicated on the assumption that US guidance is being performed well and in experienced hands.

When I trained from Internal Medicine I learned to perform the IJ with landmark techniques. Then I learned US, and it is a big difference and much safer for patients. The research is starting to focus on subgroups of people/conditions or refining techniques eg. thrombocytopenia and malignancy or infection or in plane vs out of plane, etc.

I also agree with the difficulty note about skill refinement on the non-difficult patient to allow good technique and success in the difficult case. But the caveat is that only a handful of people are acutally how Netter drew them (22.2% per AC Gordon JVIR Vol 9 no2 333-338). So based on external appearance we don't know who will be difficult in reality until the landmark fails.

As a related aside the FAUST study from the ACC supported US use for femoral arterial catheterization as a reduction in complications and time to cannulation.

Jason Nomura

Unknown said...

I read that the catheter is measured in Fr’s and one Fr is approximately the size of a human hair. The standard catheter is 18 Fr, so that would mean it’s about the size of 18 hairs in a bundle? That doesn’t seem like much.

Is the Ultrasound-Guided Central Venous Catheter more or less the same size?

Skeptical Scalpel said...

I don't know where you read that 1 French is the size of a human hair.

It is actually 1 Fr = 0.22 mm. 18 Fr = 6 mm in diameter.(

Most central venous catheters are about 7 Fr or 2.3 mm in diameter.

bigjimricotta said...

I thought that French was the diameter in mm times pi(3.14) which is the CIRCUMFERENCE in mm. So an 18 Fr catheter is 18mm circumference.
So the diameter is 18mm divided by 3.14 which equals 5.7mm. Hence an 18 Fr catheter is 5.7 mm in diameter. As a vascular surgeon, I have done probably thousands of central lines. No question in my mind is that ultrasound for jugular catheterization is much safer and easier. However, for subclavian I think it is very hard to see the subclavian vein under ultrasound. And you are right about the 7 Fr catheter being 2.3 mm in diameter----7mm divided by 3.14 = 2.3 mm.
French is the circumference of the catheter in mm.

Skeptical Scalpel said...

I'm not going to argue about 0.3 mm. Thanks for commenting.

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