It’s been a while since a collected tips and tricks post. Previously we’ve had posts on cannulation, bag-mask technique and laryngoscopy. Time to get back to vessels and some odds and ends on central lines.
Anaesthetists are skilled at many things. Airways. Making scrubs look fashionable. Or deliberately unfashionable. Even making small talk. Sometimes without the aid of chemicals to relax the patient you’re making that small talk with.
They are also required to be pretty good with obtaining negotiated permission to leave fine bore straws in veins. Sure it’s often a fairly one-sided negotiation but every now and then the vein has the last say.
Here we’ve collected a bunch of tips and tricks from colleagues that help them get there with central lines in kids. You might find some suit your practice. Some won’t. It’s by no means a complete list. After all, there’s no one way to make it happen reliably. It’s also not a “gently-finessed-blow-by-delicately-wangled-blow” description of every step along the way. Things like aseptic technique are assumed.
The anaesthetists who chipped in here (Neil Street, Gail Wong, Justin Skowno, Sarah Johnston and Andrew Weatherall) may work now at The Children’s Hospital at Westmead but have also spent time (between them) at Red Cross in South Africa, Sydney Children’s Hospital at Randwick, Great Ormond Street Hospital and Toronto Sick Kids so hopefully they’ve bumped up against many clever people along the way. So where to start? How about …
“You do need moderate extension with enough rotation to access the neck. Excessive rotation drags the apex of the triangle in front of the vein (good) or even the artery (bad). Too much rotation also turns the vein into a slit.” (NS)
“For neck lines the extension needs to be enough to allow angles to work with but it doesn’t need to be exaggerated. If the position of the head and neck is too neutral (I’m not talking about the rotation bit) you will end approaching at a steep angle and making life difficult. For femoral access a small roll under the pelvis can help quite a lot.” (AW)
Back to Anatomy
“Learn the anatomy and learn to palpate the internal jugular vein. You can feel it in the vast majority of patients, even babies, so identifying the muscles etc are not necessarily vital. If using ultrasound identify the pathway of the vein clinically first then confirm with ultrasound, not the other way around. Otherwise you will deskill.” (NS)
“You can often gently ballot the jugular vein under the finger, or even feel the ‘double flicker’ of the pressure wave. I’ve been taught to clinically evaluate the anatomy first then examine with ultrasound. I continue to do this because I think it makes me appreciate the anatomy two different ways. When I look with the ultrasound I’m trying to add it to my clinical assessment to construct a mental image of the anatomy in three dimensions.” (AW)
“The surface anatomy of younger children is different from adults. The apex of the triangle created by the sternocleidomastoids is usually lateral to the internal jugular vein. The younger the patient the more lateral it is. The most consistent landmark is the small notch in the clavicle (not the sternal notch, feel along the clavicle laterally and you’ll come across this indent where subclavius inserts). This is consistent throughout life and the internal jugular always passes under it. It is also the landmark for the “true” low approach. Go too far with the needle at that point and you’ll find the aorta.” (NS)
“Ergonomics is crucial. Comfortable table height, tools where you need them.” (JS)
“Make sure you have everything ready and prepared before you start and line it up as you will use it on your trolley (no flushing lines etc while the wire is hanging in midair). Plus ergonomics are key – stand at the head with the trolley on your right if you’re right handed with the ultrasound directly in front of you so you don’t need to turn or move to reach anything. Have the short wire on the sterile field within easy grasp to insert into the needle.” (SJ)
“The first things I need – needle, cannula and wire I have on the drapes ready to pick up without any turning or movement. Once I’ve got that vein every movement needs to be as minimal and precise as possible.” (AW)
“Get everything you need ready first. Turn around to grab something and chances are your needle will move and you’ve lost the vein.” (NS)
“Using ultrasound does not automatically make you safe. It’s clearly possible to cannulate the carotid artery whilst diligently using ultrasound to avoid doing this. The primary challenge is knowing where the tip of the needle is, and how to actually image it. A good landmark technique beats an average ultrasound technique.” (JS)
“For ultrasound guidance I usually go out-of-plane (short axis) but an in-plane view does let you view the needle tip very accurately.” (GW)
“When using ultrasound, I hold the probe perpendicular to the floor, not perpendicular to the skin surface. The second version isn’t wrong, but the image orientation is generally not the same as the orientation of the needle and you end up on slightly different tracks.” (NS)
“I’ve moved to following my cannula down with the ultrasound by sliding across the skin (the angle of the probe must be consistent) so I continually visualise the tip approaching the vein. It just makes sense to always know where you are with respect to the vein, rather than trying to make the tip appear just at the level of the vein, right where you happen to be holding the beam of the ultrasound.” (AW)
Getting that Vein to Help
“A while ago we tried out a small series with manoeuvres to see which ones actually increased the size of the vein. Head down tilt works. Liver pressure and Valsalva also work in the kids over 1 year. In the kids under 1 year of age liver pressure was the only additional manoeuvre that worked, and not very well at that.” (NS)
“If using the ultrasound, just when you think you’re about ready try to lift off just a bit more pressure. You’re almost always pressing a little bit even when you don’t think you are. Lift up and all of a sudden the vein isn’t so scary.” (AW)
Wiry Little Things
“I use a short wire [a straight, 0.018” wire] for the under 15 kg child rather than the J-loop tipped end. You can then feed a long cannula over the short wire to allow exchange to the longer wire in the central line kit.” (JS)
“For smaller babies I use a short wire initially. The control of the wire is better.” (GW)
“When using a J-tipped wire, I remove it entirely from the guide it comes in and have it separate (still with the guide to make the end straight). I can then introduce it and feed it in with much better control.” (AW)
Tips with Sharp Things
“The most frustrating thing is to have venous blood coming out of the needle, together with the inability to pass the wire into the vein. To avoid this do these:
- As you first aspirate blood freely, rotate the needle 90 degrees left and right [as in rotate on its axis]. If while doing this blood flow stops, your needle is partially in the vessel and needs slight repositioning. If blood flows well throughout this manoeuvre, the tip is hopefully unobstructed.
- Learn to image the needle tip well – modern ultrasound lets you see the tip and it’s precise position in the vein.” (JS)
“You often see experienced clinicians use a jerking needle insertion technique (multiple small, quick advances) – this punctures the vessel rather than pushing it away. The slow insertion technique often pushes the front wall of the vessel into the back wall so there is no flash back. You often end up only getting a flashback when withdrawing the needle.” (NS)
“If I don’t get immediate flashback on the way in, I advance another 5-10mm to transfix vein then put US probe down so it is not compressing vein. I hold needle with my left hand and withdraw on syringe with my right so I don’t have to let go of the needle, I can just remove the syringe and feed the guide wire in. If the wire doesn’t feed – ensure you still have flashback of blood, rotate needle, make sure head is not too far to the other side, move head more to other side and finally if none of those work I try the curved end of the larger guide wire.” (SJ)
“In small babies I cannulate first with a 24 G or 22G cannula (transfixing the vein or not). For older kids I use a needle, just like in adults.” (GW)
“Fairly recently I switched to a cannula technique because I just didn’t feel my work with a needle was reliable enough. So now I make a hole in the skin with a 19 G needle. It stops the tissues dragging down as I advance and causing distortion. I have the hub of the cannula filled with saline but I don’t aspirate as I go. Really I’ve only done this as an ultrasound technique. I find almost every time I can watch the tip into the vein, locate the cannula centrally with a bit more advancing then feed the cannula off. This means no trauma to the back wall of the vessel. When I do come close to the back wall, I generally find if I remove the needle that’s enough to have blood flowing back freely. I am yet to have a case where the blood is flowing back up the cannula freely without any effort at aspiration and the wire doesn’t feed. It always seems to feed.”
“I always check the correct venous placement with manometry as well as ultrasound in cyanotic children and little babies. Otherwise you might not know when the wire goes through the back of vein into the artery if you have transfixed the vessel.” (SJ)
Deep and Meaningful
“For depth there are a lot of formulae out there. Generally around 6 cm if < 3 kg (but beware that if you have a triple lumen central line you need to remember the proximal lumen may be 5.5 cm from the tip. So less than 6 cm at the skin and you’re at risk of the proximal lumen being out of the vein. Once they are over 4 kg, 6-8 cm is in the ballpark depending on how high your insertion is.” (GW)
“The only way to be sure where your proximal lumen is, is to aspirate on the proximal lumen while generally drawing the line back. Once it stops aspirating, you know where you don’t want to be. Advance it back in (preferably at least a centimeter) and you should be safe.” (JS)
Take a Breath Out
“Once the line is actually secured. Not before then.” (NS)
So that’s just some. We’d be keen to hear more because different people come up with different great tips all the time. And one of those tips might be the difference between feeling on top of all things, and needing a long walk at the end of the day.
These are obviously general tips and tricks and aren’t guidelines or commandments that we’re saying you should definitely do. You need to consider them in the light of your local practice and your experience. Hopefully it provokes some examination of what you do and discussions with colleagues as to what their tips might be.
Even more excellent would be if you gave us some tips back. We could always do with learning more about what we do.
Last thing. Somewhere on this page there is a spot where you can follow so you’ll get a friendly email every time a post hits the page. You could consider doing that.
The image, “Tunnel”, is from the Creative Commons area of flickr and is unchanged here. It was posted by user saffsmith.