Catheter

From ArticleWorld

A catheter is a medical tube-like device that is inserted into a part of the body such as through the skin or into the urethra for the purposes of adding things to the body, removing things from the body, monitoring the body or diagnostic testing of a body system.

Simple catheters

A simple catheter is used solely for the purposes of draining fluid or adding fluid to the body. An intravenous catheter is introduced through the skin and into a vein via a sharp needle that has the actual catheter sheathing the needle. Once the catheter and needle are inside the vein, the needle is slipped out and the catheter remains in the vein for the purposes of introducing IV fluids, medications and parenteral nutritional substances.

Larger catheters are very flexible (rubberized) and are introduced into the stomach or the jejunum for the purposes of providing nutrition. These are called gastrostomy tubes or jejunostomy tubes, respectively. A larger catheter can be introduced into the abdomen or lungs to drain large areas of fluid collections, such as abscesses or pleural effusions.

Catheters can be introduced into the urinary bladder via the urethra. A straight catheter is used to simply drain the bladder a single time. A Foley catheter is like a straight urinary bladder but with a fluid-filled balloon at the end that keeps the catheter in the bladder and allows for continuous drainage.

Complex catheters

There are complex catheters that are used in the monitoring or treatment of medical conditions. Catheters inserted into the femoral artery are introduced and passed up into the coronary arteries for the purposes of opening a balloon and relieving arterial blockages. This is called angioplasty and can be done on other arterial blockages as well. Angiography is similar but involves using a contrast medium that allows for the visualization of the coronary, brain or peripheral arteries.

Catheters can be used in a peripheral artery or a central vein for the purposes of monitoring pressures inside blood vessels. An arterial catheter is used for the continuous wave-like monitoring of the individual’s blood pressure. A central venous catheter is used to introduce especially potent medications or chemotherapy into a large bore vein. A Swan-Ganz catheter measures the venous pressure inside the pulmonary artery on a continuous basis.