Understanding a Coma
A coma is a medical emergency. Defined by a state of prolonged unconsciousness and caused by a variety of problems, a coma requires swift action. A coma may last from a few hours to months or even years. People who are in a coma that lasts longer than a few weeks are classified as being in a persistent vegetative state. Those in a vegetative state for more than a year are extremely unlikely to awaken.
The signs of a coma are closed eyes, no responses of limbs except for reflex movements and no response to painful stimuli, except for reflex movements. Many health problems can cause a coma. The first is traumatic brain injuries. Brain injuries that result from traffic collisions or acts of violence are the most common cause of comas. Next is stroke. Acute loss of blood flow to the brain followed by swelling or no blood flow to a major part of the brainstem can result in a coma. In people with diabetes, sugar levels that get too high (hyperglycemia) and stay too high or get too low (hypoglycemia) and stay too low can cause comas. People experiencing a lack of oxygen, such as those who escaped drowning or been resuscitated after a heart attack may not awaken due to lack of blood flow and oxygen to the brain. Infections, such as encephalitis and meningitis, which cause inflammation of the brain, spinal cord or the tissues that surround the brain meningitis, can result in a coma. Exposure to toxins, such as carbon monoxide or drug overdoses, can cause brain damage and coma.
Doctors must rely on physical clues and information provided by families and friends to identify proper treatment for a coma patient. Questions may include: Did the coma start abruptly or gradually? Were there problems with vision, dizziness or numbness beforehand? Any history of diabetes, seizures or strokes? What prescription or nonprescription drugs were used? Then, they may choose to run laboratory tests to check for a complete blood count, electrolytes and glucose and liver function, carbon monoxide poisoning or drug overdose. Brain scans, such as a CT and/or MRI may be needed. The doctor may also need to run an electroencephalography (EEG), a test to measure electrical activity inside the brain and determine if the patient is having coma-causing seizures.
Treatment for a coma patient varies depending on the cause of the coma. Sometimes surgery is needed to relieve the pressure due to brain swelling. Other treatments may focus on an underlying disease, such as diabetes, kidney failure or liver disease.
Sometimes a coma can be completely reversed, and the person will regain normal function. But if the brain damage is severe, the person may sustain permanent disabilities or may never regain consciousness.
For more information on support groups for coma patients and their families, visit NorthShore University HealthSystem.
