Hypoxia is a medical condition in which some or all the tissues of the body do not receive a sufficient supply of oxygen from the blood. Various types of heart disease, unhealthy or afflicted blood, impaired circulation, or diseases affecting the lungs may all produce some form of hypoxia. Since oxygen is required throughout the body to sustain health, hypoxia can have serious consequences and requires immediate medical treatment.
Symptoms of Hypoxia
The symptoms of hypoxia include increased heart rate, changes in blood pressure, rapid breathing, shortness of breath, and a blue or ashen tint to the flesh due to the lack of oxygen. The condition can also affect the nervous system, and some people develop confusion and slurred speech.
Four Types of Hypoxia
There are four types:
- hypoxemic hypoxia
- anemic hypoxia
- stagnant hypoxia
- histotoxic hypoxia
Even though they are all similar to each other and each type produces the same result, the way in which the process takes place is unique to each kind of hypoxia; the impairment of oxygen transfer from the lungs to the destination tissue occurs at different stages along the way.
In hypoxemic hypoxia, the oxygen level in the blood going to the tissues is too low to saturate the hemoglobin. The cause: a deficiency in the amount of oxygen available to breathe, often due to lower air pressure at high altitudes, or a failure in the lungs to properly transfer oxygen into the blood.
In anemic hypoxia, either the level of hemoglobin is too low, causing insufficient oxygen transmission through the blood, or the hemoglobin has been damaged and is no longer available to transport oxygen to the body tissues. Without sufficient hemoglobin, the blood cannot pick up enough oxygen from the lungs to carry to tissue throughout the body.
In stagnant hypoxia, the blood is healthy and picks up the correct amount of oxygen from the lungs, but the flow to the tissues is reduced or impaired.
In histotoxic hypoxia, the tissue cells receive the correct levels of oxygen but are poisoned or damaged and cannot make use of the oxygen they receive. The blood is healthy, the lungs function normally, and the hemoglobin levels are capable of carrying the oxygen, but the destination tissues are unable to correctly utilize the oxygen sent to them, due to some physical injury or other impairment.
Hypoxia and Anesthesia
Anesthesia during surgery can sometimes cause hypoxia. A physical blockage of the respiratory passages can occur as the tongue is anesthetized, causing it to fall over the air passages. Mucus and other foreign materials can also collect over the airways and obstruct the normal breathing passages. Any of these occurrences can restrict air into the lungs, and deny the body the oxygen it needs.
Heart Failure During Hypoxia
Heart failure is also possible from hypoxia during the use of anesthesia. If the condition occurs, the body cannot access oxygen and the tissues, including the heart, begin to lack oxygen. If the heart muscle goes without oxygen for long enough, it can fail to function, and total heart failure can take place.
Treatment of Hypoxia
Treatment of hypoxia depends greatly upon which type it is and what the specific cause might be. If the hypoxia exists because of restricted air passages, the sole treatment is examining and removing the blockage that is preventing air from reaching the lungs. If the hypoxia occurs due to unhealthy or impaired blood, an application of direct oxygen can increase the levels while locating and treating the problem in the blood itself. For hypoxia caused by damaged tissue, the medical practitioner must examine the affected area to determine how to restore normal function.
Hypoxia and Poisons
The introduction of poisons into the system, such as cyanide or carbon monoxide, or the excessive breathing of inert gases like helium or methane can cause hypoxia. Once in the system, these foreign agents can damage hemoglobin in the blood, interfering with the transfer and delivery of oxygen to the destination tissues.