Lack of Oxygen to the Brain

Oxygen is the most important element for all living organisms on the earth. Insufficient oxygen supply to the brain can be life-threatening. The brain consists of two cerebral hemispheres, left and right. Lack of oxygen to the brain or to a cerebral hemisphere is known as cerebral hypoxia. Brain cells cannot stand oxygen deprivation. An uninterrupted supply of oxygen and nutrients is essential for proper functioning of the brain. Brain cells start dying immediately after their oxygen supply disappears. They can live only for about 5 minutes, in case of scarcity of oxygen. Thus, brain hypoxia can lead to quick death or severe brain damage.

Causes of Cerebral Hypoxia

What causes hypoxia? Take a look at the list of causes of scarcity of oxygen to the brain.

• Disorders and Diseases: Diseases like paralysis affect the muscles that promote respiration. This can lead to insufficient supply of oxygen to the brain. Various types of oxygen concentrators are used in oxygen therapies, to provide oxygen to the person. Growing tumors in the brain can create obstruction in the flow of blood and oxygen. Severe bacterial, fungal or viral infections can cause 'brain death'. Bleeding in the brain needs to be controlled immediately; otherwise it can lead to various complications.
• Complications during Childbirth: Injuries before, during or soon after the birth can lead to lack of oxygen to the brain. For smaller babies, chances of cerebral hypoxia are more, before or even at the time of birth. Insufficient oxygen can slow down the placental blood flow, leading to severe complications like cerebral palsy. An unhealthy placenta, premature abruption of the placenta, squashed umbilical cord are some of the main causes of lack of oxygen to the baby.
• Effects of Poisons: Carbon monoxide poisoning can lead to brain damage. The main carbon monoxide sources are gas water heaters, kerosene space heaters, propane heaters and stoves, cigarette smoke, propane-fueled forklifts, gasoline powered concrete saws, any boat with an engine, spray paint, solvents, de-greasers and paint removers, etc.
• Suffocation: Chances of insufficient oxygen to the brain due to asphyxiation caused by smoke inhalation are maximum in case of firefighters. Choking prevents breathing.
• Heart Diseases: In case of a cardiac arrest (when the heart stops pumping), oxygen supply to the brain also stops.
• Breathing Problems: Compression of the windpipe (trachea) can reduce the flow of air to the lungs and the brain.
• Surgical Complications: Complications of general anesthesia during surgery can result in scarcity of oxygen to the brain.
• High Altitude: At high altitudes, scarcity of oxygen is always experienced. Various types of oxygen masks can be used at such places.
• Drug Overdose: Sometimes, a drug overdose can be a cause of insufficient oxygen to the brain.
• Stroke: Brain would not get enough oxygen in case of strangulation, stroke or brain attack.
• Low Blood Pressure: Very low blood pressure is also responsible for insufficient oxygen supply to the brain. Extremely low blood glucose levels can lead to 'brain death'.
• Drowning: Drowning in lakes, rivers or swimming tanks, etc. can lead to insufficient supply of oxygen to the brain.

Hypoxia Symptoms

Following are the signs of insufficient supply of oxygen to the brain. Following symptoms can be noticed during mild cerebral hypoxia.

• Poor judgment
• Inattentiveness
• Feeling dizzy after standing up quickly
• Uncoordinated movements
• Memory Loss

Symptoms of severe cerebral hypoxia include

• No response to light
• No breathing
• Complete unawareness and unresponsiveness (coma)

An individual with a completely dead brain can be alive, if the heart is functioning. Patients who are in coma may display some signs that indicate functioning of some parts of the brain. The amount of brain activity may vary from person to person. Here is an overview of the effects of decreased oxygen supply to the brain.

Effects of Cerebral Hypoxia

Cerebral hypoxia occurs suddenly and unexpectedly. Effect of carbon monoxide poisoning can be noticed days to weeks after the event. But when it is noticed, it can be unexpected and sudden. There is always very little time in hand to treat the person affected by cerebral hypoxia. So, most of the time, it leads to severe complications.

• Prolonged vegetative state can be noticed, in which the person is not alert, though he may be found breathing. He may even open his eyes, but he would not respond to the surroundings. Some may survive in this state for a longer period; but usually such patients die within a year.
• Brain dysfunction can lead to bed-ridden position, causing bed sores.
• Lung infections causing pneumonia can be a result of lack of oxygen to the lungs and brain.
• Insufficient supply of oxygen to the brain can cause clots in the veins.
• While recovering from cerebral hypoxia, the patient may suffer from certain psychological and neurological problems like amnesia, hallucinations, memory loss, and muscle spasms, for some days.

For how much time the brain suffers from lack of oxygen determines the severity of cerebral hypoxia. Overall health of the individual also plays an important role in case of hypoxia.

Cerebral Hypoxia: Prognosis and Treatment

Doctors can diagnose cerebral hypoxia after physical examination of the patient. If they know the medical history of the patient, then they can diagnose the condition immediately. Blood tests, CT scan, ECG, EEG, etc. also help diagnose the condition. The treatment may vary according to the cause but patients need breathing assistance (mechanical ventilation) immediately. Prompt supply of oxygen and medications help control the heart rate. Blood supply and fluid supply may help raise the blood pressure (bring back to normal levels). Certain medicines like phenytoin, phenobarbital, valproic acid, or general anesthetics (which cause temporary loss of bodily sensations) help stop/prevent seizures.

Cerebral hypoxia prognosis depends upon how long the brain was deprived of oxygen and how severe the effect of lack of nutrition to the brain was. Cardiopulmonary resuscitation (CPR) if started right away, can save the life of the individual. If the brain lacks oxygen for a very short period, coma can be reversible. The person can again work normally. Some patients may recover only a few functions, depending upon the extent of brain injury. The risk of death or brain death is higher if the person is unconscious due to scarcity of oxygen to the brain, for a longer period. The chances of meaningful recovery are lower in such cases.

A balanced diet prevents the formation of toxins in the body. It promotes smooth functioning of the body systems. Practicing 'pranayama' and other breathing exercises along with 'yoga' or other regular exercises help improve the intake of oxygen. This in turn improves the function of body cells and organs. Healthy diet and regular exercises thus help you lead healthy life.