section 5 chapter 22 the role of ultrasound in central vascular access device placement so we are going to talk about options for vascular access devices we are going to talk about the veins that are accessed for central line placement techniques to obtain venous access and then the potential complications of central venous access so a little bit of background central venous access plays a vital role in the care of really ill patients sometimes they need iv antibiotic therapy they also can monitor their venous pressure but with a catheter they can also use that for dialysis a chemotherapy port or also total parenteral nutrition which is a feeding method that bypasses the gi tract um total parenteral nutrition um they give fluids into a vein to give the patient their nutrition it's used when that when someone can't have anything by mouth um central vascular access devices or catheters and they are placed where the tip of this catheter is in the superior vena cava which is most often used the type used depends upon the type of therapy or the patient characteristics or the number of infusions evaluation prior to device placement is very important for the device to be successful so the most common veins that they use for central access is going to be the basilic vein brachial vein cephalic veins also larger veins the subclavian than the internal jugular so initial puncture is through these vessels and then they slide the catheter down into where it needs to be usually the superior vena cava so here are the vessels showing the central veins including the internal jugular brachiocephalic and superior vena cava and here's a chest x-ray showing a pic line it says it's on the left side but when we look at an x-ray it's backwards so this is our left but it is the patient's right this is the patient's left and you can even see the left marker here so this this is incorrect this is a right sided picc line central vascular access device options there are non-tunneled where it's just placed within the skin into a central peripheral vein and the top the tip of the of the of the catheter resides at the atrial caval junction and they use these um for critical care temporary dialysis catheters apheresis catheters small bore polyurethane catheters pig lines they are secured at the puncture site with sutures less commonly or just with tape so this type of access is for days two weeks not not um for a very long time they will use tunneled to help provide stability and it's more comfortable the tip still resides at the atrio cable junction however it is tunneled under the skin to the puncture site the point at which the catheter exits the skin from the tunnel is the exit site and usually it's several centimeters away from it and that helps reduce the risk of infection the exit site is not near the neck and can be hidden so tunneled vascular access devices are used for long-term dialysis or apheresis um or so apheresis is just another term for dialysis uh implanted ports um the device is attached to a plastic or titanium or reservoir and then the entire system is placed under the skin the reservoir has a silicone septum that is accessed with a non-coring needle so it's just like a pincushion under their skin so that they can get their injections there intermittent therapy weekly or monthly and then because the device is under the skin no dressing is needed so here's an implanted port and so this is in the patient's chest single frontal image showing implanted port compatible with a high flow contrast injection small caliber catheters are placed um via the superficial veins of the upper or lower extremities uh more common than the upper extremities so that would be the basilic and cephalic veins basilic is preferred because of the larger diameter therefore it it is able to accommodate higher flow volume up to 100 i mean sorry up to 80 milliliters a minute um the brachial vein is also a good choice however that is not a superficial vein location next to the artery uh increases the risks of puncturing that artery so the cephalic vein is a superficial vein however since it is smaller in diameter it has a lower flow volume rate at 30 ml a minute lower extremity veins saphenous veins veins on the feet can also be used if they don't have an access vein in the upper extremity and that would be more common with little babies and for um kids and then we use ultrasound they use ultrasound to guide in placement of these catheters typically short term and they change them out most common sites are internal jugular vein and subclavian veins the internal jugular vein is superficial making access and cannulation easier right ijv is preferable due to its straight course right to the heart and the external jugular vein can also be used if the patient doesn't have a suitable ijv so we are going to use ultrasound to assess the ijv prior to device placement and for guidance during placement so when they use ultrasound guidance it helps to increase success for the device as well as other complications which occur could occur they could nick something on the way in some things that you want to document would be the depth of the vessel from the skin whether or not it's patent of course um the diameter of the vessel and then the relationship of the or closeness of the internal jugular vein to the cca they don't want to nick the cca of course and cause if we nicked it that would cause a pseudo-aneurysm here's a transverse image of the left neck showing ijv which is slightly anterior [Applause] there it is this image is very very dark it's very hard to discern uh strap muscle versus ijv that i uh assume this is the ijv here and this is cca so we can they can also use this subclavian however it is more difficult because of the clavicle subclavian and other extremity veins shouldn't be used for cannulation patients that have chronic renal insufficiency or chronic kidney disease kidney disease they want to make sure that they preserve those vessels for dialysis you can also use common femoral vein in emergency situations if if there's no other option however using the common femoral vein is associated with higher rates of mechanical and infectious complications so of course since you're using a vein you want to make sure the vein is not thrombosed that is patent and where it lies in relation to other arteries or structures maybe they might have bypasses in their legs or even in their arms the ability to access the target vein uh size and patency vessel compressibility tests the patency of course that's compliant of the um coaptation where we see the vessel walls come together non-compressible veins of course with echogenic material indicates thrombus so here's a patient who has a thrombosed ijv and i would also show color i'm not color but power doppler as well so if you have the prf set high to look at the cca the prf is set too high to identify venous flow you have to make sure that you set your prf accordingly um of course important to distinguish veins from arteries you don't want them poking into an artery when they're supposed to be going into a vein caliber is very important to determine the type of access device and they can accommodate they have to be big enough um so we're going to be able to identify the needle and the radiologist or whoever is doing the um implanting the device is going to be able to see their needle real time of course we're going to they're going to be sterilizing the site with betadine you're going to be using um an ultrasound uh sheath cover transducer cover um to to keep it sterile you have to put it in a sterile sleeve sterile sheath long and trans images needle is visualized of course once it enters the skin and it's very easy to see that um metallic uh needle here's um someone scanning and that's all sterile once initial access to the vessel is obtained guidewire's catheter sheaths are advanced into the vessel and then they confirm it with a chest x-ray if it's up in the chest on ultrasound the access device can be observed within the lumen of the vessel so here is a picc line in the basilic vein complications can be reduced by using ultrasound guidance minimizes additional venous intervention reduces and preserves access sites so the patient's needs should be assessed for potential benefits from placement of the device each time that vein is accessed it damages the layers of the vein and that can lead to a thrombus within that vessel also poking into a vein and into an artery can cause a fistula where we have an abnormal connection between an artery and a vein that that happens sometimes and it would require removal of the device non-target puncture occurs when you when they accidentally encounter a neighboring structure um risk can be minimized by iding all the vessels that are in the area there if an arteries puncture of course needles should be immediately immediately removed and pressure applied because that can cause that will cause a pseudo-aneurysm so they have to hold pressure to make sure that the artery seals itself off they can also inadvertently puncture the lungs causing a pneumothorax i'll go ahead and pause here we just probably have maybe a slide or two left for this next screencast