Coma

What is a coma?

A coma is a deeply unconscious state. A person in a coma cannot be wakened up. They are not aware of their surroundings. They may have muscle jerking, but they cannot move on purpose, even in response to pain.

How does it occur?

Coma can happen when a serious illness or injury damages the central nervous system (CNS). The central nervous system is made up of the brain and spinal cord. Coma may result from:

• accidents or blows to the head
• bleeding in the brain
• infections
• seizures
• tumors
• pressure on part of the brain
• drug or alcohol overdose
• stroke
• lack of oxygen, as may happen in cardiac arrest, severe lung disease, or carbon monoxide poisoning
• severe imbalance of chemicals in the body
• other conditions affecting the function of the CNS, such as a period of very low blood pressure during which the brain does not get enough blood flow.

What are the symptoms?

Someone in a coma appears to be asleep and does not respond to loud noises, touch, or shaking. Except for unintentional muscle jerking, they do not move.

Symptoms before a coma happens may include:

• weakness
• lack of energy
• restlessness
• decline in the ability to think and reason
• seizures.

Other symptoms depend on the underlying cause of the coma.

How is it diagnosed?

Coma is diagnosed by a physical exam and information about what happened when the coma started. The healthcare provider will also need information about the person's medical history and any medicine he or she is taking.

To help find the cause of the coma, tests such as the following may be done:

• blood tests
• a brain scan, such as a CT (computed tomography) or magnetic resonance imaging (MRI)
• a brain wave test, called an electroencephalogram (EEG)
• a spinal tap, a procedure in which spinal fluid is withdrawn through a needle and examined.

How is it treated?

The treatment depends on the cause of the coma. Some people who are in a very deep coma may need intensive care. They may need a ventilator to help them breathe. Medicines and food and fluid may be given through the veins or through a feeding tube.

Some people recover fully after a coma. Some recover but have permanent brain damage. Others live on in a state in which they sleep and wake but do not recover awareness or the ability to interact. This is known as a persistent vegetative state. Some die without regaining consciousness.

Many hard ethical and quality-of-life questions may arise while someone is in a coma. For example, how much should be done to keep someone alive who may not regain consciousness? These questions may need to be addressed by healthcare providers, family, staff, and possibly clergy. Some people make such decisions for themselves before they become ill by completing advance medical directives. Advanced medical directives are documents drawn up ahead of time that express your wishes about treatment in case you later become unable to speak for yourself.

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Published by RelayHealth.
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