Peripheral Intravenous Catheter
Simply put, these catheters are inserted into the veins located in the peripheral areas of the body, such as the arms and legs. Peripheral veins lie in the extremities, away from the central part of the body. So, when it comes to administering medication through these veins, peripheral intravenous (PIV) catheters are an obvious choice. Although they can be placed easily, expert help is necessary for proper insertion. These catheters are short and their length varies from 2.5 cm to 7 cm. They are manufactured in a variety of diameters from 14 gauge to 26 gauge. Also, these catheters are designed to be used for a short duration only. So, usually after a period of 72-96 hours, the catheter is removed from the site of insertion.
✦ Midline Peripheral Intravenous Catheters
When medication needs to be delivered for a longer duration, say 2 to 4 weeks, replacing PIV lines after every 3 to 4 days is not a feasible option. In such situations, midline peripheral catheters may be recommended. They are used when the duration of treatment varies from 1 to 6 weeks. The catheter, usually inserted in the upper arm, is pushed until its other end reaches the axillary region (armpit). These catheters are longer than PIV lines, with their length varying from 3 to 10 inches.
Central Venous Catheters
When larger veins located in the central circulatory system need to be accessed, experts opt for central venous catheters (CVC). This type of catheters are often introduced into the chest and pushed until their tip reaches the superior vena cava―a large diameter vein that supplies deoxygenated blood to the heart. They are also used to access the internal jugular vein (located in the neck) and the femoral vein that lies in the groin area.
Unlike peripheral catheters, the central venous catheters are longer and designed for long-term use. When access to a specific vein is needed for a longer duration, ranging from a few weeks to several months, central venous catheters are recommended. Also, their size is larger, which helps deliver large volumes of medication, blood and nutrients in a short amount of time. People suffering from chronic ailments may require long-term intravenous administration of medication. For instance, long-term treatment of antibiotics or chemotherapy may be given using central catheters. Kidney dialysis, that involves purifying the blood and removing the waste from the body, is also carried out using these catheters. The following are the main types of central venous catheters.
✦ Peripherally Inserted Central Catheter (PICC Line)
Similar to peripheral catheters, the PICC line is inserted from the extremities, such as the upper arm. However, it does not terminate into a peripheral vein. Rather, it is pushed through these veins, until it reaches the inner larger diameter veins that are in proximity to the heart. The PICC line terminates at the superior vena cava or cavoatrial junction.
✦ Tunneled Catheter
This long, flexible tube is inserted surgically―one extremity of the catheter lies close to the heart, while the other extremity of the catheter is seen danging outside the body. With the help of ultrasound and fluoroscopy, the catheter is introduced into a vein in the neck area, and then advanced into a large vein close to the heart. The other end of the catheter is tunneled subcutaneously and eventually comes out from the side of the chest. Tunneling helps to hold the catheter firmly in its position as well as decreases the chances of an infection.
✦ Implanted Port
An implanted port consists of 2 parts; the reservoir that is shaped like a disc, through which medicines or fluids are delivered. The second part is the catheter, a slender tube connected to the reservoir and placed into a large vein. An implanted port is placed in such a way that no part of it lies outside the skin. Even the disc-shaped opening of the catheter from where the medication are delivered lies completely inside the skin. Although the skin at the site of insertion may appear slightly protruding, it is hardly noticeable. The port can be placed in the extremities, but it is usually inserted in the upper chest area. With the help of a special needle, fluids and medication are delivered subcutaneously into the catheter.