Although most people may think of ventilators when they hear the words "life-support machine," many other types of machines may be used to sustain one's life. The type of life-support machine used depends on the medical condition of the patient and the reasons for the use of life-support machines. Patients with life threatening illnesses may make the choice to use life-support machines while they are still of sound mind and capable of making their own decisions.

Types

There are four main types of life-support machines. The first is a ventilator, which forces air into the lungs of a patient who cannot breathe on her own. The second type is a pacemaker, which is used for those who have irregular heartbeats, or for those who suffer from an abnormality of the blood vessels. Next are dialysis machines, which are most commonly used for patients who suffer from kidney failure.

Features

A ventilator works by forcing warm, oxygenated air into the lungs while removing carbon dioxide. A plastic tube is inserted through the mouth and into the trachea, and is then hooked up to the ventilator which monitors every breath of the patient while regulating the air pressure at which the patient receives the air.

Pacemakers are used most frequently for those who suffer from an irregular heartbeat or rhythm. They are surgically inserted below the skin, and emit electrical impulses that remind the heart to beat normally.

Dialysis machines are used for both short and long term use, sometimes as a temporary measure to maintain the patient's health until they can receive a kidney transplant or to prolong and provide a quality of life for people who are not transplant candidates.

Hemodialysis is often used three times a week to help cleanse the blood and remove the build-up of deadly toxins. Hemodialysis machines work by removing the patients blood, running it through the machine to cleanse it, and then pumping it back into the patient. This process happens simultaneously with the use of a shunt.

Significance

Life-support machines enable patients to survive for a period of time while their body is recovering from a specific illness or injury. They benefit patients who only need them for a short time, as well as people who are attempting to maintain quality of life for the long term.

Life-support machines are also beneficial in the event that the patient is deemed "brain dead." In these circumstances, the organs continue to receive oxygen-rich blood flow to keep them functioning until they can be removed for transplantation.

History

The ventilator evolved from the principle of negative pressure, which was developed in the 1800s. These often looked like a phone booth and enabled the patient to maintain breathing by decreasing the air pressure inside the machine, although the patient still had to do much of the work necessary to receive oxygen. The "iron lung" used during the 1920s through the early 1950s was also based on the negative pressure principle. It wasn't until the late 1950s that ventilators that used a positive pressure and pushed air into the lungs were created.

In 1788, Charles Kite wrote "The Recovery of the Dead," which proposed that electrical discharges to the chest could result in resuscitation. This was studied throughout the 1800s, and in the the 19th and 20th centuries, trials began on electrical stimulation and their effects on the heart. However, it wasn't until the 1930s when Dr. Albert Hyman invented the world's first pacemaker, used mainly in operating rooms for emergency resuscitation.

In 1913, a pharmacologist at Johns Hopkins University wrote an article about cleansing the blood through hemodialysis. This proved to be an inspiration for a Dutch doctor by the name of Willem Kolff, who is considered to be the father of dialysis. He invented the world's first artificial kidney in 1943, intended to solve acute kidney failure. It was the basis of Dr. Kolff's invention which lead to the invention of the world's first noninvasive dialysis machine, named the Scribner Shunt after its inventor, Dr. Belding Scribner.

He came up with the idea of using two tubes, one inserted into an artery and one into a vein, which allowed for the circulatory process to continue while the patient's blood was cleansed of toxins. in 1962, Dr. Scribner opened the world's first outpatient dialysis center, designed to help prolong the life of those who were waiting for a kidney transplant.

Misconceptions

Many believe that life-support machines are used only for those who are comatose or critically ill. They are, however, also used for those who have a life-threatening disease or injury, such as paralysis, who are attempting to maintain a normal life. An example of this is Christopher Reeve. He relied on a ventilator to breathe for him a majority of the time, and before his death, was still able to lead a productive life.

Many also believe that life-support systems are used only in a hospital. Again, this is not true. The use of noninvasive ventilators are becoming more popular for those who wish to live at home. Patients who receive dialysis are able to reside at home while visiting a dialysis treatment center on scheduled days.

Considerations

An advance directive such as a living will or a do not resuscitate order in place long before any injury or illness arises insures that your wishes are followed. If you do not want to be placed on life support or wish only to be placed on a life-support machine for a short period of time, putting that in writing guarantees that your treatment wishes are granted even if your family wants the opposite. It is never too early to have an advanced directive composed and signed.