What is catheterization?

Indications and Procedures

Many different types of catheters exist, and they can be used for many different purposes. What they all have in common is the placement of a tube (catheter) into a body cavity. The tube is used to draw a gas or liquid from the cavity or to inject a gas or liquid into the cavity. The most common uses of catheterization are the opening of an airway for breathing, the withdrawal of urine from the bladder, and the injection of dye or other substances such as an intravenous (IV) drip into blood vessels.

Catheterization can be used to assist in the breathing process. This procedure may be necessary when the patient’s airway is blocked, the patient is unconscious and unable to breathe, or the patient needs help to breathe. The tube or catheter is placed into the mouth, nose, throat, or lungs. Oxygen passes through the tube and into the lungs, where it can be absorbed by the blood. Catheters can also be used to remove secretions from these same areas to open the airway and improve breathing. They are also necessary in many emergency situations to open and maintain breathing. At times, a catheter must be introduced directly into the lungs through an incision in the neck, near the Adam’s apple; this procedure is known as a tracheostomy. A catheter may also be introduced into the patient’s nose to transport oxygen into the lungs. Catheterization is important for maintaining breathing during surgery under general anesthesia, when the body’s breathing mechanisms are shut down.

Another common catheterization procedure involves the introduction of a urethral catheter. This type of catheter is inserted into the urethra to drain urine from the bladder. Such a procedure may be necessary to empty the bladder when the urethra is blocked, or it may be used to collect urine when the person is unable to control his or her own bladder.

An area where catheters are being used more frequently is heart diagnosis and surgery. In cardiac catheterization
, a catheter is inserted into a large blood vessel (a vein or artery) in the upper arm or groin area. The physician then maneuvers the catheter into the heart and uses it to inject a dye directly into the organ. An X ray can show the distribution of the dye within the heart, allowing the physician to see if and where any coronary arteries are blocked. In addition, cardiac catheters can be used to determine blood pressures within the heart, the amount of oxygen in the blood in the heart, and how the valves are functioning. More recently, cardiac catheters have been developed to perform some types of surgery. A good example is balloon angioplasty
. Using similar procedures to insert the catheter, the cardiologist guides a specialized catheter into the coronary artery to the area of the blockage. A small balloon on the end of the catheter is inflated, pushing the fatty material blocking the artery
against the blood vessel wall and opening the artery to allow for the normal flow of blood.

Uses and Complications

Catheterization has been used safely and successfully for many years. When people are unable to breathe on their own, airway catheters have been instrumental in saving lives and making such patients more comfortable. Such procedures have been widely used on a daily basis, with few complications.

Likewise, urethral catheters are routinely employed to control the flow of urine from the bladder. This type of catheterization can be seen in many clinical settings. Although caution must be used to prevent the introduction of bacteria into the bladder and subsequent infection, this procedure is considered to be safe and effective.

The overall success rate of cardiac catheterization has been good, with few deaths resulting from the procedure. It is a valuable tool for the diagnosis of heart diseases and disorders because a major incision in the chest is avoided. This procedure is performed many times each day in all cardiac care units. Angioplasty has also been successful, but it is useful for only some types of blockages. A major risk of angioplasty is rupture of the artery if the balloon is inflated too much. When this happens, open heart surgery is necessary to prevent death. The death rate from angioplasty is less than 1 percent, however, and the success rate exceeds 90 percent. Another problem with balloon angioplasty is that in 33 percent of the cases, the blockages re-form within six months. Nevertheless, this procedure offers a good alternative to coronary artery bypass surgery.

Perspective and Prospects

The use of catheterization for airway management was first tried in 1871 by Friedrich Trendelenburg. Through the years, such procedures have been improved. Catheters will continue to be instrumental for airway management.

The cardiac catheterization of a living human being was done by Werner Forssmann in the 1920s: He performed the procedure on himself. His techniques were further developed by André Frédéric Cournand in the 1940s, for which he won the Nobel Prize in Physiology or Medicine in 1956. Continued advances in the procedure and improved technology have increased the applications of cardiac catheterization. New and better procedures, which will continue to replace some types of open heart surgery, are expected in the future.

Bibliography

Askari, Arman. T, and Medhi H. Shishehbor, eds. Introductory Guide to Cardiac Catheterization. Lippincott, Williams, & Wilkins, 2010.

Finucane, Brendan T., and Albert H. Santora. Principles of Airway Management. 3d ed. New York: Springer, 2003.

Karch, Amy Morrison. Cardiac Care: A Guide for Patient Education. New York: Appleton-Century-Crofts, 1981.

Kern, Morton J., ed. Cardiac Catheterization Handbook. 3d. Philadelphia: Saunders, 2012.

Nordlicht, Scott M., Alan N. Weiss, and Philip A. Ludbrook. Why Me? Approaching Coronary Heart Disease, Cardiac Catheterization, and Treatment Options from a Position of Strength. St. Louis, Mo.: Northern Lights, 1999.

"What Is Cardiac Catheterization?" nhlbi.nih.org, January 30, 2012.