The Facts About Intravenous Catheter Lines
Central venous catheters are a special type of intravenous catheter (tube) which are usually inserted in the operating room. They are threaded through a vein in the neck (the external or internal jugular vein) or a vein in the upper chest under the collar bone (the subclavian vein) into a large central vein in the chest (the superior vena cava). There are two general types of catheters, those that are permanently placed under the skin with no catheter coming out through the skin (an internal catheter), or those that come out through the skin (the external catheter).
The choice of an internal or external catheter usually depends on the specific needs and preferences of the individual and their health care provider. If the catheter is going to be used frequently and for infusions lasting several hours, then an external catheter is preferable since it does not require a needle to be placed through the skin to deliver the needed medications. If the catheter is to be used frequently, the skin overlying the reservoir will often become too weak and may lead to infections. The internal catheter requires no special care when it is not being used since it is completely under the skin. The external catheter requires a sterile dressing which should be changed once or twice a day and may need to be periodically injected with heparin (a blood thinner) to prevent it from clotting. From an individual's perspective, internal catheters are preferable unless the person requires frequent or continuous use of the catheter.
A few years ago there were significant concerns that central venous catheters would have too great a risk of infection in persons with HIV due to their suppressed immune systems. However, in the past couple of years many institutions have reported favorable experiences in adult and pediatric groups of patients and no higher infection rates compared to non-immuno-suppressed persons with central venous catheters. If a patient develops an infection in a central venous catheter it can usually be treated with antibiotics, but occasionally the catheter may need to be removed.
Now let's examine specific catheter types and discuss their advantage and disadvantages. The care guidelines for catheters discussed are only general guidelines to give you an idea of what is involved in getting and maintaining a catheter. For specific care directions, you will need to refer to your health care provider for instruction. Nobody wants to have a central catheter put in their body, but if your health care provider determines that you need one, knowing which catheter best fits your medical and personal needs will help you to adjust to the new catheter in your daily routine.
Peripheral Venous Access
This is the typical "hospital IV" line put in your hand or forearm when you are admitted to the hospital. It is a short catheter, usually 3/4 to 1 inch long, inserted into a small peripheral vein and designed to be temporary. These catheters need to be changed every three days, or more often if they dislodge from the vein. Because the veins used are small and have less blood flowing past the catheter, many medications can irritate a peripheral vein. There is a plastic dressing over the catheter, which has to be kept clean and dry at all times. These peripheral IV lines work well in the hospital, where there are nurses to monitor and change them frequently, but are impractical for extended home use because of the potential for dislodging the small catheter from the vein. You have to be careful when moving your arm and daily activities become a little more difficult. Blood cannot be drawn for lab tests from a peripheral catheter. A peripheral catheter needs to be flushed with a saline and heparin injection after every use or at least twice daily if not in use. Saline is a salt solution used to clean or "flush out" the catheter and heparin is flushed into the catheter to prevent blood from clotting in it between uses.
Midline Peripheral Catheters
This type of catheter is inserted into your arm near the inside of the elbow and threaded up inside your vein to a length of 6 inches. One brand name of this type of catheter is Landmark®, but several brands are available. It is no more painful than having a peripheral IV inserted because you don't feel the catheter moving up your vein. These catheters typically last about six weeks -- a perfect catheter for a short course of antibiotics, but not really practical for long-term intravenous therapy. The end of the catheter will reach a much larger vein with more blood flow and will cause less irritation of the vein. Because the catheter is so soft and the end is well inside the vein, the chances of it dislodging are much less than with a peripheral IV. It will still need to be covered with a plastic dressing which needs to be kept clean and dry. That means wrapping your arm in plastic wrap before a shower, or taking a bath instead, holding your arm out of the tub. Your nurse will clean the dressing and clean the site once a week or more. Because it is near the elbow, this type of catheter shows under a T-shirt, but it is hidden under a long-sleeved shirt. You can do most normal activities with this type of catheter, except swimming, as long as you are careful with the arm. This type of catheter also needs to be flushed with saline and heparin after each use or at least once daily if not in use. Blood may not be drawn for lab tests with this catheter.
Central Catheters, Peripherally Inserted
These catheters are centrally placed, meaning the tip ends up in the Superior Vena Cava, which is the largest vein leading directly to the heart after collecting blood from the rest of the body. Even irritating medications can be given through a central catheter because there is enough blood flow past the catheter to dilute the drug. "Peripherally inserted" means it goes into your body at your elbow and the tip is threaded up into your vein. Two brand names for this type of catheter are Groshong® and Intrasil®, though again, there are other brands. The Groshong catheters have a valve at the tip, preventing blood from backing up into the catheter, so heparin is not necessary. Groshong catheters are usually thinner and more flexible than other types of catheters and don't require a clamp, which adds bulk to the others. These types of catheters are inserted by a nurse, and are usually no more painful than a peripheral IV insertion. After the catheter is inserted, a chest X-ray is required to make sure the tip is in the right location above the heart. There is a plastic dressing at the elbow which must be kept clean and dry at all times; it is changed and the site cleaned once a week or more by your nurse. These types of catheters usually last for six weeks to six months, but frequently last even longer than that. With this type of catheter, you can do most normal activities, except swimming or other extreme movements of the arm. You can also have your blood drawn from a central catheter instead of being "stuck" each time for lab tests, if your doctor allows. The Groshong needs just a saline flush after each use or once daily if not in use, while the Intrasil needs both saline and heparin flushes.
Central Catheters, Tunnelled
These catheter tips also end up in the Superior Vena Cava, but the other end is tunnelled about six inches away under the skin on the chest. On the catheter, inside this skin tunnel, is a Dacron cuff which your skin seals around, preventing bacteria from crawling along the outside of the catheter into the blood stream. Two popular brand names of this type of catheter are Hickman® and Groshong®. The Groshong catheters have a valve at the tip, tend to be lighter and more flexible and don't require a bulky clamp. They are usually more comfortable to "wear." These catheters are surgically placed as an outpatient procedure under local anesthesia. Afterwards, the shoulder area is somewhat sore for a few days but is tolerable. The catheter will usually exit
the skin near the nipple area and since the end dangles out, it's always available for use. This makes it very easy to use for daily medications. You will usually be responsible for cleaning the catheter exit site and changing the the dressing daily. For the first two weeks after a tunnelled catheter insertion, the gauze dressing must remain dry and intact even in the shower which means covering it with a plastic dressing or plastic wrap or taking a tub bath while keeping your chest dry. After two weeks, the dressing can be changed immediately if it gets wet in the shower. The gauze dressing changes are easy to do, and once you get the hang of it, it's a quick process.
Central Catheters, Implanted Ports
Implanted ports have all of the advantages of a central line except they are not always immediately available for use. A port is a small titanium reservoir with a rubber "stopper" that is attached to the catheter entering your vein below the collarbone. The whole thing is implanted under the skin in an outpatient procedure with local anesthesia and IV sedation. These catheters are usually not noticeable under your skin, but may sometimes show as a small lump. In order to use this catheter, the nurse must locate and clean the site, and place a special needle through the skin and into the rubber stopper. This can be done for each dose of medication or left in place with a plastic dressing and weekly changes. Ports that remain in place between usages are usually
bulkier and more cumbersome to "wear" than a tunnelled catheter, and the dressing needs to be kept clean and dry. The ports are made to withstand 2000 needle entries, but this does not irritate the skin over the port. Most people develop a callus that quits hurting when the needle is placed through the skin. As a patient, you can be taught to clean the site and access the port with a needle, but it is difficult to learn and complicated to do.
This article was provided by Seattle Treatment Education Project.