Hypoxic encephalopathy is a condition in which the entire brain receives insufficient oxygen, but the brain isn’t completely without its oxygen supply. This particular condition refers to an oxygen deficiency to the brain as a whole, rather than a part of the brain. Encephalopathy is a term used to describe any injury or damage to the brain.
Although it most often refers to injury sustained by new born infants, the term "hypoxic ischemic encephalopathy" can be used to described any injury that occurs when blood flow to the brain is nonexistent or insufficient. This may occur from a drop in blood pressure,
cardiac arrest
, or a blocked or ruptured blood vessel. The result is a reduction in or a lack of oxygen to the brain, which causes significant damage to brain tissue.
Hypoxic ischemic encephalopathy can be fatal. Within as little as five minutes of oxygen deprivation, brain cells can begin dying. The disease can also cause long-term damage, including
mental retardation
, delayed development,
seizures
, and
cerebral palsy
.
There are a variety of causes of hypoxic ischemic encephalopathy, as any injury and many health conditions may potentially cause oxygen deprivation to the brain. Some common causes of the condition are:
- Drug overdose
- Drowning
- Lack of oxygen due to smoke inhalation
- Extremely low blood pressure
- Strangulation
- Injury or complication during birth
- Cardiac arrest
- Carbon monoxide poisoning
- High altitudes
- Choking
- Compression or injury to the trachea that reduces or stops breathing
-
Complications from
general anesthesia
- Diseases that cause paralysis of the respiratory organs or muscles
A risk factor is something that increases your chance of getting a disease or condition.
Any injury, complication, or health condition that causes the brain to have a reduction in blood flow and oxygen deprivation is a risk factor for hypoxic ischemic encephalopathy.
Symptoms include:
- Mild case:
- Difficulty concentrating or paying attention
- Poor judgment
- Poor coordination
- Extreme Lethargy
- Severe oxygen deprivation:
- Coma
- No brain stem reflexes (eg, breathing and responding to light)
- Only blood pressure and heart function reflexes are functioning
The doctor must work quickly to perform a physical exam.
Tests may include the following:
- CT scan
—a scan that uses x-rays and computer software to make pictures of your brain
- MRI scan
—a test that uses magnetic waves to make pictures of structures inside the brain
- Electrocardiogram (EKG, ECG)
—a test that records the heart’s activity by measuring electrical currents through the heart muscle
- Echocardiogram
—a test that uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart
- Blood tests, including arterial blood gases and blood glucose levels
- Electroencephalogram (EEG)
—a test that records the brain’s activity by measuring electrical currents through the brain
- Evoked potentials—a test that shows whether or not the brain has an electrical response to sensations like sight and touch
Treatment depends on the underlying cause of the condition, as well as the severity of the damage to the brain. Treatment options include:
If brain function has stopped but damage is not yet extensive, life-sustaining treatment is administered.
Mechanical ventilation may be needed to sustain breathing.
Treatments are administered to maintain heart function and control blood pressure.
Hypoxic brain damage is often caused by heat, so cooling blankets may be applied to reduce the body's temperature.
Prevention is dependent upon the cause of the condition, but in most cases hypoxic ischemic encephalopathy is unexpected and cannot be prevented.
To prevent significant or long-term brain damage once the oxygen supply has been reduced,
CPR
may be administered.
Last reviewed August 2007 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 © EBSCO Publishing. All rights reserved.
