Oxygen is necessary for the normal functioning of the body. Too long a state of oxygen deficiency (hypoxia) is very dangerous for the brain and other organs - for example, the heart. They can lead to permanent disability or even death.
Brain hypoxia can have many different causes and is due to dysfunction of various systems in the body. The consequences of this condition pose a direct threat to life. Oxygen deficiency of the brain requires rapid transportation of the patient to the hospital and appropriate therapy. Only thanks to her can serious consequences be prevented.
Brain hypoxia
The brain is an organ that needs a huge amount of oxygen. Although it is relatively small, it consumes 20% of the gas that enters the body. It also reacts very poorly to a decrease in oxygen supply. The minimum threshold is about 3.3 ml of oxygenated blood per 100 g of brain tissue. If this indicator decreases, irreversible changes or even death may occur within a few minutes. Brain tissue is extremely sensitive to hypoxia - already 3-4 minutes of oxygen deficiency can permanently impair the functioning of some of its areas. The effects of oxygen deficiency in the brain are serious. To return to full health, a long tedious rehabilitation is often necessary.
Symptoms of cerebral hypoxia
The body responds quickly to a decrease in oxygen supply. Symptoms of oxygen deficiency are primarily headache, nausea, vomiting, short-term memory problems, cognitive impairment. Then fainting and loss of consciousness occur. If the patient does not receive proper care, death may occur. There is more than one cause of cerebral hypoxia, and specific symptoms can help determine it. Their violent appearance indicates a failure of the circulatory system, which does not provide enough oxygen for the brain.
Oxygen deficiency of the brain can also occur in extreme sports enthusiasts. Altitude sickness affects people who have not adapted the body to a longer stay at an altitude above 2500 m above sea level. Diluted air contains little oxygen, which can lead to respiratory and oxygen heart failure. Diving enthusiasts should also be especially careful. A rapidly changing pressure has a direct effect on the human body - under the influence of too rapid a rise, the nitrogen accumulated in the blood takes the form of bubbles and causes blockages that lead to cerebral ischemia. Hypoxia can also have a chronic course - it is accompanied by prolonged fatigue, memory problems, concentration and drowsiness.
Oxygen deficiency of the brain: causes
Brain hypoxia can be caused by impaired functioning of many systems and organs in the body. These include:
- cardiac arrest - for example, as a result of a heart attack;
- disturbances in normal circulatory function, arterial occlusion associated with atherosclerosis, embolism, thrombosis;
- sudden drop in blood pressure due to anaphylactic, hemorrhagic shock;
- developed anemia;
- violation of the respiratory system associated with pneumonia, asthma, emphysema, pneumothorax, sleep apnea.
Often the cause of hypoxia is cardiac arrest. Diabetes is also a serious risk factor - in the advanced course of this disease, blood vessels change, which leads to serious disruptions in the functioning of the whole organism. This may also be the case in older people suffering from atherosclerosis and other diseases associated with the circulatory and respiratory systems.
Types of Brain Hypoxia
Depending on the degree of ischemia, several types are distinguished.
- Complete cerebral ischemia (cerebral infarction) leads to cerebral hypoxia and is associated with a stop in the blood supply to the entire organ or region. After just 2 minutes, the oxygen supply in the cells is depleted, and the processes leading to their death are rapidly developing.
- Partial cerebral hypoxia - associated with a decrease in blood flow.
- Anoxia - insufficient blood oxygenation.
- Anemia - caused by hemoglobin deficiency.
- The hypoxemic type is a decrease in the partial pressure of oxygen in arterial blood.
- Histotoxic type - associated with an enzymatic defect.
Oxygen deficiency in a newborn
Fetal hypoxia is a lack of oxygen in the blood or tissues. Mechanisms responsible for child hypoxia include:
- abnormal oxygen flow through the placenta;
- improper gas exchange through the placenta;
- other diseases in women.
Sometimes, during or immediately after birth, the baby’s brain is hypoxic. Then the so-called perinatal hypoxia appears. This can happen, for example, as a result of pressure on the umbilical cord, the wrong degree of oxygenation of the fetus.
Diagnosis of intrauterine oxygen deficiency
Diagnosis of fetal well-being is based on:
- cardiotocography;
- capillary blood test;
- gas test.
The first signal of hypoxia is an abnormal cardiotocography of a child (CTG). A constantly accelerated heartbeat (tachycardia) indicates a slight lack of oxygen, and then the onset of bradycardia during uterine muscle contractions indicates a long-term oxygen deficiency. This means that the child is in a state of emergency and it is advisable to resolve the pregnancy as soon as possible.
A capillary blood test consists in taking micro-samples of blood from a child (most often the head) to determine the pH value. A blood pH value indicates that acidosis occurs due to hypoxia. Currently, this test is often carried out with a gasometer.
The gasometric test allows you to control violations of the acid-base balance and gas exchange of the body. In a newborn, a blood sample can be taken for examination from an artery or umbilical cord. The partial pressure of carbon dioxide (pCO 2) and the partial pressure of oxygen (pO 2), as well as the level of oxygen saturation of the blood, are determined.
The greater the intrauterine oxygen deficiency, the more extensive the area of hypoxia. With oxygen deficiency, the child can consume meconium in utero. Local oxygen deficiency leads to an increase in intestinal motility and intrauterine consumption of meconium. This is proof that the child was in a state of emergency.
The effect of perinatal hypoxia
Perinatal hypoxia can cause an abnormal adaptation of the newborn to an independent life. Respiratory mucosal aspiration and respiratory distress syndrome may occur. There may also be brain damage (ischemia, encephalopathy). Some children have minor developmental dysfunctions that can be easily corrected, others may experience neurological abnormalities, such as cerebral palsy or epilepsy.
Currently, many of the effects of perinatal hypoxia can be prevented. A thorough assessment of the condition of the fetus during childbirth, early intervention and the rapid completion of childbirth makes it possible to eliminate or reduce the risk of damage to the brain of the child. Advances in neonatology and new methods of treatment (for example, hypothermia of the head) give good results.
Hypoxia of the brain: first aid
The goal of first aid is to begin transporting oxygen to the brain as soon as possible. For this, artificial respiration and heart massage are usually done. They are performed in accordance with heart compression in the middle of the chest and breathing using the mouth-to-mouth method. If the airways are blocked by a foreign body, you can try to remove it. It is much worse if airway blockage is the result of laryngeal edema (for example, with diseases of the respiratory system or an allergic reaction). Then, obstruction of the airways requires the introduction of special drugs, and in extreme cases, tracheotomy.
It is necessary to call an ambulance for the patient. Prior to her arrival, if possible, information should be collected on the victim, including what medications he is taking, is he allergic to anything, is he suffering from a chronic illness or has recently become ill (such as a heart attack), or has undergone surgery .
Hypoxia of the brain: treatment
Treatment of cerebral hypoxia always occurs in a hospital, and its goal is also to initiate the transfer of oxygen to the brain. A detailed course of therapy depends on the cause of cerebral oxygen deficiency.
Fortunately, the brain is a neuroplastic organ, which is why appropriate rehabilitation exercises and regular use of hyperbaric oxygen therapy make it possible to create new neural circuits that serve as damaged neural groups. In the case of cerebral oxygen deficiency, treatment should be carried out with the participation of specialists in hospital or rehabilitation centers and on an individual basis, taking into account the causes of hypoxia and its duration.