Hypoxia refers to a lack of oxygen supply to body tissues. Hypoxia requires adequate medical management to avoid serious consequences. What are the treatments ?
Hypoxia means a decrease in the amount of oxygen supplied to the organs by the blood. Hypoxia can be tissue, brain or fetal depending on the cause of the lack of oxygen carried by red blood cells in the blood. In case of significant hypoxia, we speak anoxia. Coma and death are the most serious consequences of hypoxia. What is the difference between hypoxia and hypoxemia? How diagnose hypoxia? What are the treatments hypoxia?
Definition: what is hypoxia?
The supply of oxygen to the human body is provided by respiration. Breathed oxygen travels through the lungs where they pass into the blood attaching to hemoglobin in red blood cells, which transport oxygen to the tissues. In this context, hypoxia refers to a decrease in the amount of oxygen supplied to the organs by the blood. “It is a consequence of hypoxemia which is the decrease in the amount of oxygen transported by red blood cells in the blood, specifies Dr Nicolas Devos, resuscitator anesthesiologist. Oxygenation of organs and tissues is then insufficient, and this can result in suffering of the cells constituting the affected organs. Depending on their origin, we can speak in particular of:
- tissue hypoxia, which refers to an insufficient supply of oxygen in relation to the needs of the body’s tissues. Tissue hypoxia is not seen directly, the consequences are seen when the pressure sore appears.
- cerebral hypoxia is a form of hypoxia (a reduced oxygen supply), specifically involving the brain. When the brain is completely deprived of oxygen, the term used is rather cerebral anoxia.
- fetal hypoxia, which corresponds to a decrease in oxygenation of the fetus. During pregnancy, fetal hypoxia is most often chronic and evolves over several weeks or months. We are talking about chronic fetal distress.
What is the difference between hypoxia and hypoxemia?
Although the two terms are often used interchangeably, they refer to two different situations. “Hypoxemia occurs when the partial pressure of oxygen in the blood (PaO2) is below normal (the normal value is between 80 and 100 mm Hg). Uncorrected hypoxemia leads to hypoxia”, says the doctor. On the other hand, hypoxia is defined as reduced oxygen supply to the tissuewhich is not directly measured by a laboratory value.
What is cerebral anoxia?
In case of significant hypoxia, we speak anoxia. Anoxia is a lack of oxygen in body tissues. Several causes can be at the origin of this disorder, which can itself concern one or more tissues, or even all the organs. “Potentially fatal, anoxia is an absolute medical emergency to save the patient’s life or limit the possible consequences and sequelae.“, insists the resuscitator anesthesiologist.
blood gas is a medical examination that involves taking arterial blood (from the arteries of the arm or leg). It allows measure oxygen blood gas pressure (O2) and oxygen (CO2), as well as blood pH (or blood acidity). We can thus confirm hypoxia (decrease in the oxygen level in the blood) thanks to this examination.
What causes hypoxia?
The causes of hypoxia can be of three types:
► Decreased oxygen supply (altitude hypoxia for example). At altitude, oxygen becomes scarce. Mountain sickness, pulmonary or cerebral edema, watch for mountaineers and high-flying hikers. It is therefore better to pass a hypoxia stress test to know the capacity of your body to adapt to this new environment. On a plane, the phenomenon of hypoxia is avoided thanks to the pressurization of the cabins. The air pressure is then maintained at that of sea level inside the aircraft, independently of the external atmospheric pressure. A device that allows passengers to breathe normally.
► Respiratory function failure (lung infection, chest trauma etc.).
► Decreased oxygen transport in the direction by red blood cells (disease of red blood cells such as thalassemia for example or much more simply anemia).
What are the symptoms of hypoxia?
Symptoms of hypoxia are usually:
- a tachycardia : best clinical sign of hypoxia
- a hyperventilating by increasing the work of breathing
- a cyanosis : the skin takes on a bluish tint
What are the consequences of hypoxia?
Severe hypoxia can throw a person into the comaor even lead to dead if it is not effectively managed by cardio-circulatory arrest.
What are the treatments for hypoxia?
In hypoxia, it is common to use oxygen therapy. A device (oxygen cannula, nasal probe, oxygen mask) is used to administer the gas. “The treatment of hypoxia depends on its origin, course and severity. It is generally based on oxygen therapy to restore a satisfactory level of blood oxygen” assures our interlocutor. This additional supply of oxygen can be done by using:
► The lungs: with an oxygen mask, covering the nose and mouth, to supply oxygen to the lungs; or in the most serious cases by recourse to artificial ventilation.
► Blood oxygenation directly without going through the lungs: In some rare and extremely serious cases, the lungs do not allow a supply of oxygen, and extracorporeal circulation can be used.
Thanks to Dr Nicolas Devos, intensive care anesthesiologist at the Clinique de l’Europe in Rouen.