Welcome to the Ultrasound Leadership Academy (ULA) summary blog series. This week, we discuss peripheral IV placement. The ULA is essentially an online advanced ultrasound education experience put on by the team from Ultrasound Podcast which brings cutting edge learning to emergency medicine personnel through a variety of interactive platforms including video lectures, google hangouts with experts, simulation, live conferences and real time scanning with a pocket-sized ultrasound device known as a Vscan.
Over the next year I will be posting summaries of the key learning points from my experience. If you want to learn more about the program you can visit Ultrasound Leadership Academy or Ultrasound Podcast to see more from the hosts of this awesome program.
Prior to reading this post, I suggest you review our previous post "Introduction to Procedural Ultrasound" if you are not familiar with ultrasound guidance terminology and basics.
The idea of placing peripheral IVs under ultrasound guidance in relatively new however it is becoming an important asset for difficult access. In the emergency department, all of our patients are not blessed with plump venous pipes that are just asking to be poked. Rather, the population we see is dominated by issues such as obesity, chronic illness, and intravenous drug use, making venous access a precarious task. We could of course just place central lines in all our difficult access patients since it is a fairly straightforward procedure. Unfortunately, central lines are loaded with complications ranging from blood stream infections, to thrombosis, to pneumothorax, and placing these lines unnecessarily may actually be providing more harm than benefit.
Enter the ultrasound guided peripheral IV. It is a procedure that can be learned online and immediately practiced at the bedside. It decreases the number of central lines that need to be placed in difficult access patients and it likely increased patient satisfaction (less pokes = happier patient). Plus studies looking at ED techs and nurses performing these procedures successfully means that this is a procedure that can be performed by an array of ED personnel and streamline work flow efficiency.
We know that the more distal we are in the extremity the higher the likelihood that the venous cannula will survive. However, once we are placing an ultrasound guided IV, the hand and forearm veins have usually already been tried and likely will not be successful. Therefore the main veins we are using for this procedure will be the basilic, the median cubital, the brachial and the cephalic. Starting your search in the antecubital fossa will usually be ideal.
WHAT YOU NEED
You will need your standard IV set up (tourniquet, saline flush, hep lock, chlorhexidine or alcohol pad, venous catheter, tape) plus a few other items:
- High frequency (linear) probe
- Sterile ultrasound gel packet
- Tegaderm (to place over ultrasound as sterile cover)
- Longer venous catheter (1.8 or 2.5 inch), 1.1 inch catheters have a high fail rate
Like placing any peripheral IV, positioning will be important. Ideally the patient will have the arm slightly abducted at the shoulder, fully extended at the elbow and supinated at the wrist. You can have the patient place their arm along their side or away from the bed, resting on a table. Make sure the bed is up high enough for you, if standing, so you do not have to hunch over. As discussed in the previous post, Introduction to Procedural Ultrasound, you want to have your ultrasound screen on the opposite side of the bed from where you are performing the procedure and in your direct line of sight to avoid turning your head away from your site of cannulation.
Unlike placing regular IVs, you cannot take a shallow angle as the veins you are cannulating are usually deeper and therefore taking too shallow of a course through the soft tissue may leave you with minimal catheter within the lumen of the vein. This puts the catheter at high risk of failure down the line.
Picking the Vein
The optimal vein for cannulation will have a few centimeters of a relatively straight course, be less than 1 cm from the skin surface and not have overlying complicating structures such as arteries or nerves. We know that the more superficial a vein that is cannulated, the more likely it will survive. A recent study showed that IVs placed < 0.4 cm in depth had a perfect survival rate while IVs placed > 1.2 cm in depth only had a 30% survival. In terms of location, the antecubital fossa seems to be better than the brachial region ( 83% survival versus 50% respectively).
Finding the Vein
I usually start in the antecubital fossa, especially since veins here tend to be more superficial. Often, they are easily compressible so make sure to start with gentle pressure to avoid collapsing them on initial look and missing a potential target. Begin your search with a short axis view, looking for vessels coursing through your screen which will appear round or elliptical if cut slightly oblique. Compress these structures to confirm they are veins, arteries will be pulsatile and difficult to collapse. You can also use color doppler you identify artery and vein but this is often not necessary. Two tips to improve your view when you are having a difficult time:
- Depth: You want to decrease the depth of your screen as much as possible to increase the size of your target on screen.
- Gain: The structures you see on screen may be too bright or too dark, so simple adjustments of the gain can drastically improve your structure differentiation.
Long Versus Short Axis
As you develop your own practice for ultrasound guided procedures you will begin to decide when and where you will use long or short axis technique. Some literature shows that long axis may increase the visibility of your needle tip for PIV placement but conversely a study looking at individuals just learning ultrasound found the success rate of cannulation to be higher using short axis. I would recommend practice using both approaches in order to be able to use either technique based on patient specific factors. For example, you may prefer long axis if you have an artery directly underneath a vein of interest to prevent puncture into the artery.
Pearls and Pitfalls
- Extravasation: If there is concern that the IV has extravasated, you can throw on the ultrasound probe to assess this. Extravasated fluid should look like edema in the soft tissue. If you are still unsure and want to confirm that the IV is in the proper place, you can inject agitated saline into the catheter and observe the lumen of the vein for movement.
- Beware of posterior wall puncture: If you are going to use a short axis view approach, be sure that you are always aware of your needle tip. You may want to use a technique called 'Leading the Needle' as described on previous post (and shown above), to always be sure that your needle tip is not too deep.
- Tenting: When you are attempting to cannulate, the anterior wall can tent down and collapse all the way to the back wall. When you pop through the wall, you may puncture both walls and therefore be outside of the vein lumen. In order to get back into the vein, pull back a very short distance to allow the needle to pop back into the lumen, which you should visualize on ultrasound. At this point you can pass your catheter safely into the proper position.
- Upgrading your IV: If you already have a small distal IV, such as in the hand, and need to obtain larger-bore access more proximal for resuscitation and/or specific contrast study, then normal saline is your friend. Place your tourniquet just proximal to your target site as usual and inject 50-100 cc of saline (you can use flushes) into your current distal IV. This will plump up the veins in the arm very nicely and make hitting your target vein that much easier.
Ultimately the most important part of this procedure is to be aware of your needle tip at all times. If you lose sight of it, attempt to find it by fanning with the ultrasound first (You can jiggle the needle very softly to help look for signs of where the needle tip is if it is unclear). Practice will make perfect, so don't be discouraged if you miss a few. Some of the lines you place will fail, but you can minimize this my aiming for more superficial targets. I highly suggest watching the two instructional videos from SonoSite below to further solidify your understanding of the procedure:
Vascular Access Lecture at Emergency Ultrasound Teaching
THAT'S IT FOR THIS WEEK
If you are interested in learning more about the ULA learning experience, visit their website below:
More on procedural US can be found in "Introduction to Bedside Ultrasound," Volume 1 & 2, from Dr. Mallin and Dr. Dawson. If you are interested in purchasing these ebooks for less than $1, visit Ultrasound Podcast Consumables.