Hypoxic Coma (Oxygen Deprivation Coma)

Hypoxic or oxygen deprivation coma is one of the two major categories of coma managed by the staff of ICRI.

Oxygen deprivation to the brain occurs when insufficient or no oxygen reaches the brain, either because the respiratory or breathing system fails or because the circulatory system (heart rate and blood pressure) fails.

Oxygen is the life-giving fuel that all the tissues of the body depend upon, but while most of our tissues have an oxygen reserve and can tolerate short periods of time without a fresh supply, the brain does not store any oxygen. As a result, if the oxygen supply to the brain is cut off, the brain dies within two minutes.

Many times, oxygen supply is markedly decreased resulting in severe injury to the brain.

The main causes of hypoxic coma are:

1. Near drowning (usually in children under the age of 4, but possibly at any age)
   
   
2. Cardiac arrest (from MI (heart attack) or adverse reaction to anesthesia or medications) (from severe blood loss, or anaphylactic shock, etc.)
   
   
3. Respiratory arrest (Allergic, traumatic or in response to medications, overdose, etc.)
   
   
4. Stroke (closing off of a main artery to the brain)
   
   

Each of the above causes can occur singly or in combination.

Hypoxic injury to the brain differs from traumatic injury to the brain in that more of the brain is affected in a diffuse manner and seizures are more common during the long term follow-up period. However, the end result is the same whether the brain has suffered a lack of oxygen or a severe blow:

1. A certain number of brain cells are destroyed.
   
   
2. A certain number of brain cells are hurt but still alive, though not functioning.
   
   
3. A certain number of brain cells remain intact, of which many had no function before the incident and maybe considered as a reserve which may be able to take over or to learn new functions.
   
   
4. Some of the pathways carrying information from the stem of the brain to the surface or cortex break down.
   
   

The principles of management of hypoxic coma are the same as those for management of traumatic coma:

1. Persistent good medical care
   
   
2. Prolonged good nursing care and nutrition
   
   
3. Judicious use of medication
   
   
4. Intense multisensory stimulation
   
   
5. Intense physical activity all for a prolonged period of time.
   
   

While the arousal and recovery rates from prolonged coma in patients followed by the staff of the I.C.R.I. indicates a 90% rate of arousal from coma and a 35% rate of recovery to independent function, the figures represent a mixed group of individuals. If those who are in a hypoxic coma are separated from the traumatic comas, the arousal rate is still about the same, but recovery to functional independence for hypoxic comas is about 15%. This figure is still 15 times greater than expected if prolonged intense therapies are not applied and therefore warrant the undertaking of every effort possible for a long enough period of time.

Mihai D. Dimancescu, M.D.
Director of International Coma Recovery Institute
Chairman Emeritus, CRA

Copyright © 1985-2000, * Coma Recovery Association, Inc.