Anoxic Brain Injuries

The human body needs oxygen to survive and the brain uses 20 percent of the body's total oxygen. Oxygen is necessary to metabolize the glucose that is used to provide the energy required by all of the body's living cells. What the brain does with up to 90 percent of its energy is to send messages or electrochemical impulses and to maintain the neurons' ability to send them.

When oxygen supply is interrupted, anoxic brain injuries occur. They are part of the acquired brain injury classification and are sometimes grouped as hypoxic-anoxic injuries. In both cases, oxygen deprivation is the cause of the injury. Hypoxic injuries are caused by a significant lack of oxygen being supplied to the brain; anoxic injuries are caused by a total lack of oxygen.

Two of the three most common types of hypoxic-anoxic injury (HAI) can each have devastating effects on the victim and the family. They are anemic anoxia and ischemic anoxia. The third, anoxic anoxia, only occurs when there's not enough oxygen in the air for the body to absorb, resulting in altitude sickness.

Most Frequent Causes of Anoxic Brain Injuries

With anemic and ischemic anoxia, the resulting profound thinking, emotional and movement impairment(s) can be slow to overcome, taking months or years. Anemic anoxia is caused by hemorrhage, perhaps a wound that is bleeding profusely, where not enough oxygen-carrying hemoglobin is getting to the brain. Carbon monoxide poisoning or chronic anemia can also result in anemic anoxia.

Ischemic anoxia occurs when an event such as a stroke or heart attack limits the blood flowing to the brain. Causes for ischemic anoxia include anesthesia mistakes, hardening of the arteries, drowning or other asphyxia, chest trauma, electrocution, severe bronchial asthma and barbiturate poisoning. The resulting cognitive and physical deficits will likely require much consultation with physical and speech therapists, as well as a neuropsychologist.