(First published on blog.5minsono.com on May 4, 2015)
Last week we spoke about the literature behind ultrasound-guided peripheral IV placement (USGIV) and now we’re going to talk about how to actually do it. (If you need to catch up, here’s the link to part 1)
Which probe should you use? Your probe of choice is going to be the linear probe. You can do a one or two person technique, but a study by Rose et al 1 showed no difference in overall success or time. The downside to that is that you are using two providers for a procedure you could be doing with just one person, which wastes time and resources.
How do you orient the probe? There are 3 ways you can orient the probe: Longitudinal, transverse, and oblique. While the longitudinal approach seems to be easy on the vein gel simulators, there are a few things you need to keep in mind. The first thing is that both phantom model studies and studies in live patients have not shown any improvement in accuracy. In a phantom model study the longitudinal approach was found to take longer than short axis (5.02 minutes vs 2.36 minutes) with no difference in accuracy 2. Similarly, a study on actual patients by Mahler et al found that there was a trend toward decreased success with long axis (although this was not statistically significant), and long axis took three times longer to perform than the short axis.3 There are, likely, two reasons why these findings occurred: Firstly, most patients that require USGIV are not going to have veins that are nice and straight like they are in the US phantoms. Secondly, it’s pretty difficult to keep the 1 mm beam of US completely in line with the vein and the needle.4 An oblique approach has been described, but it has been shown to be inferior to both the long and short axis.5
Which vein should you choose? As far as which vein to choose, don’t be picky. I look everywhere. I start around mid-forearm, up through the antecubital fossa and all the way up to around the mid upper arm, looking for the most superficial, most straight, plumpest and not-close-to-any-other-structure vein. In my experience, there is no such thing as the easiest place to get an USGIV, because everybody’s anatomy is different. Is the patient extra fluffy? I’ll probably be able to find a vein easily in the forearm that is otherwise non-palpable. Is the patient a twig and suffers from IV drug abuse? I’ll probably have to go for an upper arm vein. Beggers can’t be choosers, and I really need that IV. I did a fairly extensive lit review, and compiled the data from all the USGIV studies I could find. Below you’ll see a chart where the studies out there found their access.
There is one caveat to this data, however, and it’s that some of these studies only looked at certain areas of the arm, and did not have free range to attempt cannulation wherever they thought would be best.
Predictors of success There are a few things that help predict if you’ll be successful and those include the depth and width of the vein, the type of catheter you use and the experience of the operator.
-Depth and width of the vessel – Intuitively, a larger and more shallow vessel seems like it would be easier, and the literature supports that. Using standard length catheters, this study showed the highest success rates were with veins that had a diameter >0.4cm, and a depth between 0.3-1.5 cm. 6 This study (also using a standard length catheter) showed that the odds ratio of successful cannulation increased by 1.79 per 0.1 cm increase in the vessel diameter. 7
Type of catheter you should use. Most of the “standard” catheters we have in the ED are between 1-2 inches in length. While this might work okay if you have a superficial vein in the forearm, most of the time a standard length catheter is not going to cut it. You’ll likely be able to cannulate the vein and maybe draw some blood, but these get dislodged or infiltrate with alarming frequency. Check out the chart below
When looking at the data above, you need to keep in mind a couple of things: First, many of the studies didn’t really standardize how long after they placed the IV that they recorded the infiltration. The studies may have looked at the rate of infiltration over 2 hours, or in one case, 48 hours 8 (obviously, this one was one with the highest infiltration rate). Also, some of these studies used the standard 1-2 inch catheter, and some used longer catheters, so it is a fairly heterogeneous group.
Some of the studies use seldinger technique and have really good success rates. Some of the them used arterial lines as peripheral IV’s, some used guidewire kits that were made for peripheral IV’s, and one even used a 14 gauge central line kit for peripheral access.9-12 Personally, I think the 2.5 inch 18 gauge catheters work fine, but those other techniques are definitely options you can consider.
XP points. For those of you that don’t play video games, XP stands for experience. In regards to USGIV, XP points add up the more of these procedures you do. The more XP points you have, the more successful you will be. Any new technique or procedure has a learning curve and takes practice to master.13 One study with ED techs found an increase in success from 45.8% to 87% when the providers had >10 successful US-guided IV lines. 14 Another study that only included nurses that had >25 prior successful cannulations had impressive success rates of 94% of the 3,300 patients they attempted in one center in 2010. 15
The next post will wrap up this mini-series and talk about the actual USGIV procedure itself.
[showhide type=”post” more_text=”CLICK HERE FOR REFERENCES” less_text=”Click here to hide references”]
Rose JS, Norbutas CM. A randomized controlled trial comparing one-operator versus two-operator technique in ultrasound-guided basilic vein cannulation. J Emerg Med. 2008;35:(4)431-5. [pubmed]
Blaivas M, Brannam L, Fernandez E. Short-axis versus long-axis approaches for teaching ultrasound-guided vascular access on a new inanimate model. Acad Emerg Med. 2003;10:(12)1307-11. [pubmed]
Mahler SA, Wang H, Lester C, Skinner J, Arnold TC, Conrad SA. Short- vs long-axis approach to ultrasound-guided peripheral intravenous access: a prospective randomized study. Am J Emerg Med. 2011;29:(9)1194-7. [pubmed]
Jaffer U, Normahani P, Singh P, Aslam M, Standfield NJ. Randomized study of teaching ultrasound-guided vascular cannulation using a phantom and the freehand versus needle guide-assisted puncture techniques. J Clin Ultrasound. 2015. [pubmed] (epub ahead of print)
Tassone HM, Tayal VS, Weekes AJ, Garner CL, Norton JH. Ultrasound-guided oblique approach for peripheral venous access in a phantom model. Crit Ultrasound J. 2012;4:(1)14. [pubmed]
Witting MD, Schenkel SM, Lawner BJ, Euerle BD. Effects of vein width and depth on ultrasound-guided peripheral intravenous success rates. J Emerg Med. 2010;39:(1)70-5. [pubmed]
Panebianco NL, Fredette JM, Szyld D, Sagalyn EB, Pines JM, Dean AJ. What you see (sonographically) is what you get: vein and patient characteristics associated with successful ultrasound-guided peripheral intravenous placement in patients with difficult access. Acad Emerg Med. 2009;16:(12)1298-303. [pubmed]
Fields JM, Dean AJ, Todman RW, et al. The effect of vessel depth, diameter, and location on ultrasound-guided peripheral intravenous catheter longevity. Am J Emerg Med. 2012;30:(7)1134-40. [pubmed]
Gregg SC, Murthi SB, Sisley AC, Stein DM, Scalea TM. Ultrasound-guided peripheral intravenous access in the intensive care unit. J Crit Care. 2010;25:(3)514-9. [pubmed]
Mills CN, Liebmann O, Stone MB, Frazee BW. Ultrasonographically guided insertion of a 15-cm catheter into the deep brachial or basilic vein in patients with difficult intravenous access. Ann Emerg Med. 2007;50:(1)68-72. [pubmed]
Stone BA. Ultrasound guidance for peripheral venous access: a simplified seldinger technique. Anesthesiology. 2007;106:(1)195. [pubmed]
El-Shafey E, Tammam T. Ultrasonography – guided peripheral intravenous access – regular technique versus seldinger technique in patients with difficult vascular access. Eur J Gen Med 2012;9(4):216-222