Emergency Ultrasound Section Forum
How do I place a peripheral IV with ultrasound?
This topic was addressed in a listserve discussion that included this response from Chris Moore (which is one of the best summaries on the subject that we've seen):
While I am not aware of any published"standard technique" I can give you my take on it after learning itthe hard way and teaching it for several years. I consider ultrasound guidedperipheral venous access in challenging patients to be among the hardestprocedures I regularly perform in emergency medicine. However, once you reallyget it it can be extremely effective, fairly quick, and very helpful. I believethat some of the published literature that is not so favorable for thisincludes people who are not sufficiently experienced. I think it probably takesmore than 30 procedures to get really comfortable, and I recommend my residentsstart on patients that aren't necessarily difficult access/ not severelydehydrated, etc. I also find that these days many residents haven't or didn'tperform regular peripheral IV access (non-ultrasound guided) in medical school,so they often need to learn this skill as well.
As it is not a completely sterileprocedure I generally don't use a probe cover, though I clean the skin andprobe well -- generally I keep the probe and the gel a bit away from the wherethe needle enters the skin. Other reasonable options include a tegaderm cover,sterile or non-sterile gloves, or an actual probe cover.
It is pretty much essential that youhave longer angiocaths -- we generally use 20 gauge 1.88" angiocaths, asopposed to the standard 1.25" angiocaths. While with superficial veins youmight be able to get away with a shorter angiocath, anything deeper than a fewmillimeters even if you get in you want to thread it far enough up so that itdoesn't dislodge. While I strongly advocate a long-axis (in-plane) approach forcentral venous access as it is a bigger vessel nearer to important structures,in peripheral venous access I usually use a short-axis approach. This isbecause it is much harder to keep smaller vessels in view and peripheral veinsoften don't run in a straight line long enough to keep them in one frame. Ashort-axis approach allows you to make sure that you are directly over themiddle of the vein. It is important to get a sense of the axis of the vessel.As most of you are aware, the problem with a short axis approach is that youcan cut across the shaft of the needle higher up or miss it entirely. In ashort-axis approach it is important to keep "fanning" the plane ofthe US proximally and distally, often while jiggling the needle, to find outwhere the tip is. What you are looking for in the short axis approach is thetarget sign, when the needle tip is seen as a dot within the vein. However, myexperience is that often when you first see this you still need to advance thecatheter a few more millimeters in order to thread it. I believe this isbecause the endothelium of the vein "tents" into the middle of thevessel before the catheter pierces it. You may be able to feel a slight"pop" as the catheter pierces the endothelium. While many look for aflash, I prefer to keep my eyes on the screen and make sure the tip of theneedle is traveling far enough into the lumen of the vein. I then thread it,you should also be able to feel if it threads easily.
We try to document our USguided peripheral access procedures and I am pretty sure we are billing them,though I am not aware of how many are being reimbursed for how much. In orderto bill you should have "image archival of real-time needle entry",which can be challenging if you don't have someone to record while you do theprocedure. After I complete the procedure I usually check and record the flushusing the ultrasound proximal to the IV. However, if you are not concernedabout billing and don't need it for QA I'm not sure you should worry aboutpictures.
Some other tips
-- Vessel choice. I usually look betweenmid forearm and mid upper arm. The basilic vein is often a great choice, it isquite medial and concealed between a few millimeters of fat. It does not travelwith an artery, which is an advantage, although it is not tethered and mayroll. The often paired brachial veins are right next to the artery, but havethe advantage of not moving around so much. Tourniquet is helpful.
--Make sure its a vein. Especially indehydrated patients, peripheral arteries may compress quite easily. Any vesselyou are going for, compress it half way into an oval and watch a few secondsfor any evidence of arterial pulsations.
--Ideal depth. Probably about 5mm. Lessthan 3mm you usually don't need US and more than 1 cm is tough, though I'vegotten them at nearly 2cm deep.
--Find the axis of the vein. Use theprobe to find the axis of the vein by sliding it up and down keeping the vesselin the center of the screen, and make sure the needle is in that axis. Veinsdon't always run straight.
--Place your hand overthe catheter. I often see residents holding the catheter like a pencil, withtheir hand under the catheter. This limits your maneuverability in terms offlattening the catheter as described below. Place your hand over the top of thecatheter grasping it between the thumb and middle finger, with the index fingerready to thread it.
--Center the vein onthe screen. Approach with the needle at ~45 degree angle in the middle of theprobe, at the right axis, and about the same distance from the probe. Once yousee the target sign, flatten the approach as you advance it to visualize thetarget sign as the tip of the needle pierces the endothelium and goes into thevessel, can avoid backwalling.
--Backwalling. Mayoccur, and may actually be necessary in really dehydrated patients as it may bealmost impossible to pierce one side without the other. Try to follow theneedle tip if it goes deep to the vessel, then watch carefully as you draw itback and the vessel should tent open.
--Local anesthetic.Very helpful, particularly for deeper vessels or while you are learning.Lidocaine in an insulin or TB syringe works well, and can help you get a senseof the orientation / depth if you look at depositing the anesthetic usingultrasound.
Learning this ondifficult patients can be quite time consuming, but gets much faster as you getgood at it. With time you get a real sense of exactly where the needle is goingto show up on the screen based on depth and approach etc.At some point some ofthe technology for vessel location may make this a lot easier... but untilthen.... am sure many others have other tips or different approaches but hopethis helps.