A coma is a state of deep unconsciousness from which a person cannot be aroused. A person in a coma cannot react to events in his environment.
Normally, information from a person’s surroundings is passed from the brainstem into the cerebrum. This feedback allows a person to be conscious of and react to his environment. When this system breaks down and a person is no longer able to respond, a coma can result.
A coma may be caused by:
Risk factors for coma include:
Risk factors for brain injury include:
Symptoms of a coma include the following:
Since the patient cannot speak, information from friends, family members, and witnesses is important when diagnosing the cause of a coma. The doctor will want to know about the person’s medical history, as well as any drug or alcohol use. It is important to provide honest information in order to help with treatment.
The doctor will test reflexes, listen to breathing, examine the eyes, and perform neurological and physical exams. In addition, the following tests may be done:
Comas are rated according to the Glasgow Coma Scale (GCS), which assesses three different functions: eye opening, motor response, and verbal response. Scores can range from 15 to 3. A lower score indicates a person is less responsive. Scores are interpreted as follows:
A coma is a medical emergency. Any unconscious person should be taken to the emergency room immediately.
Oxygen and intravenous fluids will be given, and the person’s vital signs monitored closely. He may be put on a ventilator . Doctors will work quickly to determine the cause of the coma, and further treatment will depend on the cause.
Usually, glucose is given by IV in case low blood sugar is causing the coma. Naloxone can also be given by IV if a narcotics overdose is suspected. Thiamine (vitamin B1) may be given with glucose if alcoholism or malnutrition is suspected. In some cases, surgery may correct the cause of a coma.
Once the person is stabilized, treatment will focus on providing adequate nutrition and preventing infections and bed sores .
The following can help decrease your risk of coma:
RESOURCES:
Brain Injury Association of America
http://www.biausa.org/
Brain Trauma Foundation
http://www.braintrauma.org/
Coma Recovery Association, Inc.
http://www.comarecovery.org/
CANADIAN RESOURCES:
Brain Injury Association of Alberta (BIAA)
http://www.biaa.ab.ca/
Ontario Brain Injury Association
http://www.obia.on.ca/
References:
Berger, JR. Stupor and Coma. In: Bradley, WG et al, eds. Neurology in Clinical Practice 5th ed. Philadelphia, Pa: Butterworth Heinemann Elsevier; 2008.
Hall JB, Schmidt GA, Wood L. Principles of Critical Care. 3rd ed. New York, NY: McGraw-Hill; 2005: chap 67.
Harrison's Principles of Internal Medicine . 15th ed. New York, NY: McGraw-Hill; 2001.
The Merck Manual of Diagnosis and Therapy . 17th ed. Whitehouse Station, NJ: Merck Research Laboratories; 1999.
PDR Family Guide Encyclopedia of Medical Care . New York, NY: Three Rivers Press; 1997.
Last reviewed January 2009 by J. Thomas Megerian, MD, PhD, FAAP
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.