Coma is a deep state of unconsciousness where the affected individual is alive but is not able to react or respond to external stimuli.
Sometimes, comatose patients are totally unaware of their states and environments; sometimes they are partially or fully aware but cannot communicate. There is lack of consciousness, self-awareness, sleep-wake cycle and purposeful movements in a comatose patient. But the basic life support functions, like breathing and blood circulation are retained.
Coma is not a disease. It is a symptom of a disease or a response to an event, such as a severe head injury, seizure or metabolic problem. Coma may appear slowly in conditions where there are preceding medical or neurological problems, including the secondary brain swelling that surrounds a pre-existing lesion.
The outcome of coma ranges from full recovery to death. Whether a person recovers, and to what extent, depends upon the cause of the coma and the type and extent of brain damage. It is very important to know that the outcome may remain unknown for many months.
Most comas last no longer than four weeks. However, some people in a coma shift to a persistent vegetative state, which can last for years, depending on the medical circumstances and the cause.
Initial emergency treatment of a comatose patient focuses on stabilizing the vital signs. This may rapidly reverse the coma. After emerging from a coma, many people can recover fully; some require lifelong physical and occupational therapy, while others may recover only basic functions.
Causes of Coma
Head injury or certain serious illnesses or their complications may cause a coma.
The most common causes of coma include:
- Severe head injury
- Metabolic disturbances, such as low or high blood sugar
- Tumors or other structural lesions leading to high pressure within the skull
- Bleeding in the brain or skull
- Alcohol or drug intoxication
- Brain inflammation and infection
Symptoms of Coma
The main symptom of coma is unconsciousness.
Symptoms of coma include-
- Unconsciousness. The patient may appear to be in a deep sleep.
- The patient is unresponsive to external stimuli- strong tactile (painful), or verbal stimuli.
- The patient may exhibit spontaneous body movements- shake or jerk abnormally, or the eyes may move.
- Inability to open the eyes.
- Breathing may be affected in severe coma.
- A coma does not have a sleep-wake cycle.
Treatment for Coma
Currently, there are no medicines that will shorten the duration of coma.
Diagnosis and treatment of coma begin simultaneously.
The Glasgow coma scale is used to determine whether the patient is improving, deteriorating, or remaining the same. It is a simple way of measuring the depth of coma based upon observations of eye opening, speech and movement.
Initial emergency treatment of a comatose patient focuses on stabilizing the vitals. In some cases of severe coma, the patient may require life-saving resuscitative measures. Once the comatose patient is medically stable, it is important to diagnose and treat the underlying cause of coma.
- A detailed history from the family members and friends is very important and can help determine the exact cause of coma.
- Glucose may be administered intravenously if the blood sugar level is low.
- If the coma is suspected to be induced due to a narcotic overdose, naloxone (narcan) may be given intravenously to reverse the situation.
Currently there are no medicines that will shorten the duration of coma. In fact, some medicines actually deepen the state of unconsciousness. For a patient in prolonged coma, the treatment goal is-
- Preventing infection like pneumonia or bedsores
- Providing balanced nutrition
- Physical therapy may prevent permanent muscle contractions and bone deformities.
If doctors think the coma is not likely to reverse quickly, they may insert an endotracheal tube to aid respiration and may administer oxygen.
In the case of a coma that results from a head injury, doctors may perform surgery to drain excess fluid from the head and relieve pressure on the brain.
Latest Publications and Research on Coma
- Molecular Targets in Cerebral malaria for Developing Novel Therapeutic Strategies. - Published by PubMed
- Treatment of chronic subdural hematoma with atorvastatin combined with low-dose dexamethasone: phase II randomized proof-of-concept clinical trial. - Published by PubMed
- Prognostic role of EEG identical bursts in patients after cardiac arrest: Multimodal correlation. - Published by PubMed
- The National Ambulance Surveillance System: A novel method for monitoring acute alcohol, illicit and pharmaceutical drug related-harms using coded Australian ambulance clinical records. - Published by PubMed
- Measuring stroke outcomes for 74,501 patients using linked administrative data: System-wide estimates and validation of 'home-time' as a surrogate measure of functional status. - Published by PubMed