Anoxic anoxia is caused by a lack of oxygen in the air (reduced atmospheric oxygen tension), such as at high altitudes. As a result, less oxygen reaches the blood, resulting in a lack of oxygen supply to the tissues.
Anemic anoxia is occurs when red blood cells lack the ability to carry sufficient oxygen, either due to a reduction in hemoglobin or due an alteration in the capacity of the hemoglobin to carry oxygen. It may also be the result of a deficiency in red blood cells. Health conditions frequently associated with anemic anoxia include lung disorders, chronic anemia, carbon monoxide poisoning, and acute hemorrhage.
Although anoxia can affect any tissue/organ of the body, the brain is most vulnerable. Since the brain requires a large amount of oxygen (20% of the oxygen consumed by the body is taken up by the brain alone) to function normally, the effects of anoxia are most prominent in this organ. Oxygen deprivation for 4 minutes may result in brain cell death, and permanent brain damage is likely if the oxygen supply is not restored within 5 minutes.
The signs and symptoms of anoxic brain injury depend on the duration of anoxia and the intensity of damage. The most vulnerable areas of the brain are the cerebral cortex, the hippocampus, the basal ganglia, and the cerebellum.
In the case of mild anoxia (shorter duration), the initial symptoms include lack of attention, concentration, coordination and short-term memory loss. These symptoms may be associated with headache, dizziness, hyperventilation, and sweating.
If anoxia persists for a longer duration, the extent of brain damage may be severe. This may subsequently result in confusion, agitation, peripheral cyanosis (bluish discoloration of the skin around the lips, mouth, and fingertips), myoclonus (jerky contraction of muscles), and seizures. Extreme anoxia can lead to loss of consciousness and coma.
If anoxia has been prolonged sufficiently to result in significant brain injury, it may result in coma. After recovery, symptoms such as memory lapse, movement disorders, weakness of the arms and legs, and neuropsychological issues like depression and stress intolerance, may manifest.
The symptoms of anoxia may not always be obvious at first. Your brain can last a few minutes without oxygen before any symptoms appear. At times, symptoms may be delayed and take several days or weeks to appear.
Each type of anoxia has a different internal or external cause. For example, internal causes include your heart or blood vessels not getting oxygen to your brain. External causes include less available oxygen or inhaling environmental toxins.
Carbon monoxide poisoning is one of the most common causes of toxic anoxia. Carbon monoxide is a produced when gas is used as fuel. A faulty gas stove, fireplace, or furnace can cause carbon monoxide to fill your home. It is also found in vehicle fumes.
The action of an anoxic stimulus on red cell production was studied in rabbits bled 20 ml./Kg., kept anemic for 20 hours and then reinfused with the previously removed blood. This 20-hour period of anemic anoxia was followed by a characteristic reticulocyte response, a response which was modified by nitrogen mustard or colchicine administered immediately after the 20-hour period of anemia, but was not influenced by anoxia or hyperoxia in the postanemic period. When mitotic division was arrested by colchicine during the 20-hour period of anemic anoxia, the onset of the reticulocyte response, though delayed by 1 to 2 days, was otherwise of characteristic magnitude.
Toxic anoxia stops the blood from carrying oxygen around the body effectively. It can occur after a person ingests, absorbs, or inhales certain toxins or other harmful chemicals, such as carbon monoxide.
Being aware of the symptoms of hypoxia and anoxia and seeking immediate medical care is crucial. A quick medical response can help reduce complications and determine the speed and success of recovery.
This week, continuing with a subject matter focused on different health conditions that can result in a neurological injury, we will look at anoxias in more detail. In this post we will analyze different aspects related to this health condition: starting with what causes it and all the way to possible rehabilitation treatments.
Ischemic anoxia is probably the most frequent type. In the next paragraphs we will look in more detail at the main causes for the different types of anoxias described in this section. We will also analyze the consequences and the different factors that will have a direct effect on the severity of the resulting brain injury.
Unfortunately, treatments for anoxia can vary depending on existing clinical impairments. These can go from isolated cognitive impairments to a possible brain death. However, this health condition is normally associated with both higher disability rate and dependency rates among those individuals that survive the acute phase. Some epidemiological studies indicate that up to 65% of patients who have suffered an anoxia, will require assistance to complete the activities of daily living at discharge.
On the other hand, independently of the type of anoxia that caused the brain injury, affected patients will benefit from participating in a rehabilitation program. In this way, since the impairments affecting these patients will be both physical and cognitive, they should ideally receive a multidisciplinary treatment.
Rehametrics will be very useful for those individuals who suffer from different impairments due to an anoxia because it offers them a multidisciplinary approach to rehabilitation from any location that has an Internet connection. And, of course, enabling healthcare professionals to prescribe fully personalized rehabilitation sessions that can be monitored in detail from any location that has access to the Internet.
One anoxia treatment that has shown to produce positive outcomes for many patients is hyperbaric oxygen therapy. Also referred to as HBOT, hyperbaric oxygen therapy is a non-invasive treatment used to help reverse tissue damage, as well as encourage stem cell mobilization and decrease inflammation, caused by anoxia. It does this by increasing the flow of oxygen-rich blood and oxygen absorption rates in all parts of the body, including the brain, in a controlled setting.
The five types of anoxia or hypoxia include hypoxemic, anemic, affinity, stagnant, and histotoxic. Hypoxemic anoxia happens when the oxygen pressure outside the body is so low that the hemoglobin, the chemical which carries oxygen in the red blood cells (RBCs), is unable to become fully loaded with the gas. This results in too little oxygen reaching the tissues and can occur in suffocation when a person is at high altitude, where the pressure of oxygen in the air is much less than at sea level.
Anemic anoxia results from a decrease in the amount of hemoglobin or RBCs in the blood, which reduces the ability to get oxygen to the tissues. Anemia may result from lack of production of red blood cells (iron deficiency), blood loss (hemorrhage), or shortened lifespan of red blood cells (autoimmune disease).
Affinity anoxia involves a defect in the chemistry of the blood such that the hemoglobin can no longer pick up as much oxygen from the air, even though the quantities are normal, reducing how much is delivered to the tissues.
Stagnant anoxia occurs when there is interference with the blood flow, although the blood and its oxygen-carrying abilities are normal. A common cause of general stagnant anoxia is heart disease or interference with the return of blood flow through the veins. Examples of local stagnant anoxia include exposure to cold, diseases that restrict circulation to the extremities, and ergot poisoning. When the tissue or organ itself has a reduced ability to accept and use the oxygen, it is called histotoxic anoxia. The classic example is cyanide poisoning, where the chemical inactivates a cellular enzyme necessary for the cell to use oxygen. Thus, tissue exposed to cyanide cannot use the oxygen even though it is in normal amounts in the bloodstream. Histotoxic anoxia can also be caused by exposure to narcotics, alcohol, formaldehyde, acetone, toluene, and certain anesthetic agents.
No matter what the cause of anoxia, the symptoms are similar. In severe cases, the patient is often confused and commonly stuperous or comatose (in a state of unconsciousness). Depending on the severity of the injury to the brain, the organ most sensitive to reduced oxygen intake, this condition can persist for hours, days, weeks, or even months or years. Seizures, myoclonic jerks (involuntary muscle spasms or twitches), and neck stiffness are some other symptoms of the anoxic condition.
Diagnosis of anoxia and hypoxia is commonly made through the appearance of clinical symptoms. However, suspected reduction in oxygen reaching the tissues can be confirmed using laboratory tests. The exact test that is performed is dependent on the suspected cause of the anoxia. One systemic measure of tissue anoxia is the serum lactate (lactic acid) test. When cells are forced to produce energy without oxygen, as would happen during anoxia, lactic acid is one of the byproducts. Thus, an increase in lactic acid in the blood would indicate that tissues were starved for oxygen and are using non-oxygen pathways to produce energy. Normally, the blood contains less than 2mmol/L of lactic acid. However, some forms of anoxia do not increase lactic acid concentrations in the blood and some increases in lactic acid levels are not associated with anoxia, so an elevated value for this test is only suggestive of an anoxic or hypoxic condition.
The exact treatment for anoxia is dependent on the cause of the reduced oxygen reaching the tissues. However, immediate restoration of tissue oxygen levels through supplementing the patient's air supply with 100% oxygen is a common first step. Secondary steps often include support of the cardiovascular system through drugs or other treatment, treatment of lung disease, transfusions, or administration of anecdotes for poisoning, as appropriate. 041b061a72