What do you do when expert nurses tell you they can’t obtain IV access? Do you spend 20 minutes performing an invasive central line? Does your resident finally get two IO EPAs? Or do you save the day with a slick, ultrasound guided IV?

Obtaining peripheral ultrasound guided IV access is not only a core skill in the modern ED physician’s toolbox but can be easily learned by familiarizing yourself with the basic principles and engaging in deliberate practice.

Anatomy

Equipment

1. Linear Ultrasound Transducer (L12-4)
2. Long IV – in our department, ideally the 20G 1.88inch (48mm), but alternatively the 20 G 1.25 inch (32 mm). The longer the IV, the lower risk of dislodgement
3. Sterile, individual ultrasound gel packaging
4. Chlorhexidine or alcohol swabs to clean skin
5. Tegaderm’s x 2 – One to cover the transducer, one to secure the IV
6. Normal IV equipment – tourniquet, saline lock, flush, gauze, tape

Ultrasound Guided IV Steps:

1. Tourniquet Placement – place this high-up near the axilla, just below the deltoid to maximize your options. Doing this step first gives the veins time to plump up.
2. Skin Prep – clean the skin from the tourniquet all the way down to mid-forearm.
3. Probe Preparation – Set your probe to either the venous, arterial or vascular setting. Place a dollop of non-sterile gel on the probe. Cover it with a Tegaderm, sticky-side down, pulling it across the probe to get the air bubbles out. Do not touch the probe to displace air bubbles as this can contaminate the probe.  

4. Target Location – this depends on which veins were already attempted, individual patient anatomy, and your own level of comfort. My personal practice is to target the upper arm, scanning first the median cubital region, followed by basilic and the cephalic veins.
5. Vessel Identification: When distinguishing arteries from veins, focus on pulsatility rather than relying solely on compressibility [1]. In hypovolemic patients, or when applying significant pressure, both arteries and veins may collapse. To ensure accurate identification, apply light compression and observe for pulsatility, which is a more consistent indicator of an artery. If a vessel is not compressible and non-pulsatile consider a thrombosed vein and move to a different area.
6. Consider Target Measurements – The ideal vein size is 0.4cm in diameter or larger [2]. Use the notched measurements on the side of the screen to estimate this. The ideal vein depth is 0.3-1.5 cm, with research demonstrating these veins to have more successful rates of cannulation [2].

7. Vein Trajectory – Scan your probe up and down until you’re confident you know the relative trajectory. Even better, slightly rotate your probe each time until the vessel stays in the center of your ultrasound screen while you slide up and down. This aligns your transducer to be perpendicular to the vein, ensuring your needle advancement will stay parallel to the vein. 
8. The Poke – short-axis and long-axis are both acceptable methods. You’re likely most familiar with short-axis through performing central lines, and I personally find better success with it. The key is Sequential Needle Tip Tracking (SNTT), also known as the Creep Method. Keep the probe in-front of the needle. As the needle enters the top of the screen as a bright central dot, slide your transducer away until it disappears. Then advance the needle until the dot reappears, and so on until it’s in the vein. Confirm you’re not through the back wall by then sliding your transducer away once again to confirm the dot doesn’t travel posteriorly. Moving slowly and making fine micro-adjustments is key!

9. Advance the Catheter – Once you’re confident you’re centered in the vein, drop your angle of insertion and advance the needle one more centimetre before sliding the catheter in. Some experts perform a two-axis technique here: that is, once you’re short-axis centred in the vein, they rotate to a long-axis, then advance the needle and catheter while visualizing the vein’s superficial and back walls [1].
10. Pro-Tip: Don’t Focus on Flashback – Flashback doesn’t mean your needle is in the right spot. It just means you touched a blood vessel. Instead, focus on the on-screen needle-tip alignment and axis.
11. Secure the IV – Dry the skin completely before applying a Tegaderm to avoid wrinkling. Use multiple pieces of tape to secure the IV, including under the line, over the IV hub and at the proximal end of the Tegaderm [1].

Congratulations – you’ve just completed an ultrasound-guided peripheral IV!