Hypoxia (lack of oxygen)

Chest | Emergency Medicine | Hypoxia (lack of oxygen) (Disease)


Cerebral hypoxia refers to the outer part of the brain, an area called the cerebral hemisphere. However, the term is often used to refer to a lack of oxygen supply to the entire brain. Cerebral hypoxia occurs when there is not enough oxygen getting to the brain. The brain needs a constant supply of oxygen and nutrients to function.

Brain cells are extremely sensitive to a lack of oxygen. Some brain cells start dying less than 5 minutes after their oxygen supply disappears. As a result, brain hypoxia can rapidly cause severe brain damage or death

Symptoms of mild cerebral hypoxia include: , change in attention (inattentiveness), poor judgment, uncoordinated movement

Symptoms of severe cerebral hypoxia include: , complete unawareness and unresponsiveness (coma), no breathing, no response of the pupils of the eye to light

Causes and Risk factors

In cerebral hypoxia, sometimes only the oxygen supply is interrupted. This can be caused by: breathing in smoke (smoke inhalation such as during a fire), carbon monoxide poisoning, choking, diseases that prevent movement (paralysis) of the breathing muscles (such as amyotrophic lateral sclerosis), high altitudes, pressure on (compression) the windpipe (trachea), strangulation

In other cases, both oxygen and nutrient supply are stopped, caused by: cardiac arrest (when the heart stops pumping), cardiac arrhythmia, complications of general anesthesia, drowning, drug overdose, injuries to a newborn that occurred before, during, or soon after birth (See: Cerebral palsy), stroke, very low blood pressure.

Complications of cerebral hypoxia include a prolonged vegetative state. This means the person may have basic life functions such as breathing, blood pressure, sleep-wake cycle, and eye opening, but the person is not alert and does not respond to his or her surroundings. Such patients usually die within a year, although some may survive longer

Length of survival depends partly on how much care is taken to prevent other problems. Major complications may include: bed sores, clots in the veins (deep vein thrombosis), lung infections (pneumonia), malnutrition

Diagnosis and Treatment

Prevention depends on the specific cause of hypoxia. Unfortunately, hypoxia is usually unexpected. This makes the condition somewhat difficult to prevent.

Cardiopulmonary resuscitation (CPR) can be lifesaving, especially when it is started right away. ...