Brain Hypoxia: Causes, Symptoms and Diagnosis
- 01 Sep 04:00
- Causes and types of hypoxia
- Consequences of cerebral hypoxia
- Symptoms of cerebral hypoxia
- Diagnosis of hypoxia
- Newborns hypoxia
Oxygen is the basis of all living things on our planet. If without food, a person can live a fewmonths, without water - a few days, then without oxygen - only a few minutes. To the oxygen deficit, all organs and tissues in the body are sensitive, but most of all - the brain, it is called the "critical organ" with hypoxia( oxygen starvation of tissues).
Brain on the intensity of blood flow is the first place in the body, it provides 20% of the minute volume of blood flow, and this is a very large figure. Without breaking the functioning of the brain tissue can withstand only 4 seconds of acute hypoxia, after 8-12 seconds after the end of the blood flow, a loss of consciousness develops; after 20-30 seconds, the activity of the cerebral cortex disappears and the person falls into the coma. If you do not adjust the blood supply for 4-5 minutes, the brain will die. Therefore, it is very important to have an idea of what is a hypoxia of the brain, about the main causes that lead to it, in order to prevent serious consequences in a timely manner.
Causes and types of hypoxia
The brain's hypoxia is not a separate disease, it is a pathological condition, which can cause a lot of both external andinternal factors. Arises due to insufficient supply of tissues by oxygen or disruption of its utilization by the cells themselves.
Depending on the cause of hypoxia occurs:
- Exogenous( hypoxic) is an oxygen fasting that develops when the amount of oxygen in the environment decreases. This happens, for example, when going up in the mountains. As you know, the degree of air saturation with oxygen decreases with each meter of altitude, since the ascent of an untrained person may end up in mountain disease( hypoxic hypoxia).A similar situation can be observed in the case of malfunction of ventilation systems in a closed room, on submarines, in spacesuits, and aircraft.
- Respiratory( respiratory) is a lack of oxygen in the body, which develops due to abnormalities in the respiratory organs. For example, bronchial asthma, pneumonia, tumors of the bronchopulmonary apparatus, impaired functioning of the respiratory center( overdose of narcotic drugs, damage to the brain and spinal cord), paralysis of respiratory muscles, chest trauma, etc.
- Circulatory( cardiovascular) is an oxygen fasting of tissues due to a violation of hemodynamics or local blood flow in the brain. The main causes are heart failure, shock conditions, localized blood flow disorders due to thrombosis, embolism, and atherosclerotic plaque. Recent causes may provoke the development of acute ischemic stroke in the brain.
- Gemic( bloody) - develops when oxygen transport is disrupted by blood cells. As is known, oxygen molecules are delivered to all cells in a hemoglobin-bound state. If there is not enough red blood cells in the blood and hemoglobin( anemia) or the process of binding of hemoglobin with oxygen( poisoning with methemoglobinobrazuyuschih poisons), then there is a blood hypoxia.
- Fabric( gyttoxic) - develops in case of disturbance of oxygen utilization by cells, for example, destruction or blockade of enzyme systems that take part in tissue respiration( some poisons, medicines).
During the development of hypoxia, several of its species are distinguished:
- lightning-fast - develops for several seconds and minutes, for example, hemorrhage into the respiratory center;
- is acute - occurs within several hours, for example, poisoning with methemoglobinobrazuyuschimi compounds;
- is chronic - prolonged for a long time, for example, in chronic heart failure, cerebral atherosclerosis, dyscirculatory encephalopathy.
Consequences of cerebral hypoxia
Sharp and acute cerebral hypoxia, as a rule, always leads to death if prompt care is not provided. In other cases, the effects of hypoxia depend on the degree and localization of damage to the brain tissue.
There are various general disorders, such as dizziness, chronic headache, speech impairment, memory, vision, etc. If the patient undergoes adequate rehabilitation, then in the future complete restoration of brain functions is possible, but in most casesthere are residual phenomena of varying degrees of severity.
Chronic hypoxia has a more favorable outlook for life, but reduces its quality. The human body has a unique ability to adapt to changing conditions of existence, including life in conditions of partial oxygen fasting:
- increases the depth and frequency of breathing( externally manifested as shortness of breath), reserve alveoli of the lungs begin to function, in order to increase the area of "absorption" of oxygen;
- increases the heart rate( palpitations occur), increases arterial pressure, hypertension develops), redistributed blood flow( in peripheral tissues decreases, threatened by trophic changes and increased in vital organs, brain, heart, liver, etc.);The
- bone marrow produces an increased number of red blood cells( developing erythrocytosis), which threatens the increased risk of thrombosis;
- forms collateral vessels that provide the hypoxic region with an additional portion of blood oxygen.
It is a pity, but the adaptive mechanisms of the human body are imperfect. They provide livelihoods, but lead to secondary pathological changes.
Thus, if hypoxia is not eliminated on time, then the whole body begins to suffer, which sooner or later will lead to decompensation and increase the symptoms newly.
Symptoms of Hypoxia of the Brain
Symptoms of acute hypoxia develop depending on its cause. But there are universal symptoms that are inherent in any type of hypoxia.
At first, there are signs of a nervous system overexcitation that changes within a few minutes with symptoms of her oppression and loss of consciousness. The patient is excited, he has accelerated breathing and palpitation, observed euphoria, pale skin with sticky cold sweat. Immediately changing the phase of excitation comes the phase of suppression of the brain functions - the patient is apathetic, dizziness, drowsiness, blinking of "flies" in front of his eyes, initially the consciousness is partially disturbed( stupor, sopor, somnolencija), then - completely with the development of coma of different depths. Firstly, superficial, and then deep unconditioned reflexes fall, breath and heart stops.
If at that moment the patient will receive adequate emergency care( under the ABCD reanimation principle), then in case of success all functions will be returned to the exact opposite.
Symptoms of chronic cerebral hypoxia are much more diverse. About cerebral insufficiency you might think with such patient complaints:
- is a constant dizziness;
- frequent mood changes;
- persistent headache;
- noise and ringing in the ears;
- periodic nausea and vomiting in the morning;
- progressive memory impairment;
- 's failure to focus a long time;
- fast fatigue;
- speech impairment, coordination;
- progressive reduction of mental functions, up to dementia;
- sleep disturbances( drowsiness in the daytime, insomnia at night);
- development of a depressed state or other mental disorders;
- irritability, tearfulness, vulnerability;
- is a bad assimilation of new information and a decrease in mental performance.
The most striking nosological examples of chronic cerebral hypoxia are cerebral atherosclerosis, dyscirculatory encephalopathy, hypertonic encephalopathy, sleep apnea syndrome, vertebral artery syndrome in cervical osteochondrosis.
Diagnosis of Hypoxia
Diagnosis of general body hypoxia is much easier than to diagnose local hypoxia of the brain. For this purpose, it is enough to analyze the symptoms of the pathology and medical history. Estimate the degree of lowering the level of oxygen in the blood will help methods such as pulse oximeter( measuring the degree of oxygen saturation of blood), determining the type of alkaline-acid balance in the body and the gas composition of venous and arterial blood. These surveys are enough to establish the fact of hypoxia, but in order to find its cause, more surveys are required that are selected depending on the predicted state etiology. For example, MRI for suspected stroke, laboratory blood tests in suspected poisoning.
Chronic hypoxia is often not accompanied by a significant decrease in the saturation of blood with oxygen, as the body manages to adapt to pathology and such ischemia is often local( cerebral).Therefore, anamnesis of the disease plays an important role in determining its cause( which is a person suffering from nosological forms).For example, if there is an ischemic heart disease, then you can suspect cerebral atherosclerosis, and if - hypertonic disease, then dyscirculatory encephalopathy, cervical osteochondrosis - vertebral artery syndrome.
Help confirm coronary artery bypass grafts:
- MRI and CT, PET-CT;
- ultrasonography with the study of blood flow characteristics using dopplerography;
- general and selective angiography.
In any case, a diagnostic program - an individual, depending on the degree of brain damage, general health and the predicted cause.
Treatment of cerebral hypoxemia depends on the causes of its occurrence. Only by eliminating the etiological factor can positive dynamics be achieved.
With the impossibility of etiotropic therapy, symptomatic treatment is performed. Assign drugs for the normalization of blood circulation, the regulation of vascular tone, nootropic drugs, medicines for dizziness and headache, antidepressants and hypnotics, general restorative agents and vitamins, blood-thinning and anti-aerogenic drugs.
Brain Hypoxia in Newborns
Brain Hypoxia in newborns may occur in both intrauterine development and in childbirth. Among all neonatal pathology, this condition occurs most often. Hypocrisis of severe degree can lead to the formation of fetal malformations, premature births, infant fetal death, stillbirth, severe childhood disability and death during the newborn.
Among the main causes of this condition are:
- severe somatic and obstetric mammary infections( heart failure, intoxication, insufficiency of the fetoplacental complex, premature placental abnormalities, umbilical cord disease);
- Fetal and newborn pathology( genetic diseases, developmental defects, infectious lesions, cerebral trauma of the newborn);
- asphyxiation of the newborn in childbirth, aspiration of amniotic fluid, meconium, birth trauma, swelling of the child's respiratory tract.
Often, hypoxia of the brain in the fetus occurs when the mother receives alcohol, some medicines, smoking, drug addiction, and professional and environmental production. Therefore, the health and future of her child depends on the mother's behavior.
. Treatment of newborn hypoxia is a complicated task. Immediately after birth, they conduct intensive care( release of the upper respiratory tract, tactile stimulation and artificial respiration).Further therapy depends on the cause of hypoxia: in premature infusion of surfactants, with a craniocerebral trauma - antifungal therapy, nootropic treatment, with an infection - antibiotic therapy.
If you notice any signs of a hypoxia of the brain in yourself or your child, then be sure to seek medical help, because every minute of the brain without oxygen can stand you health or life.
Hypoxia is not a disease, but a pathological condition( acute or chronic), which is accompanied by oxygen starvation of the brain and other organs. The causes of hypoxia are very high. Only eliminating them, you can get rid of the symptoms of hypoxia of the brain.