Oxygen at high partial pressure is toxic. There is a poisoning of the body that causes convulsions similar to an epileptic seizure, which in water leads to drowning, and only the correct behavior during an oxygen spasm can lead to the salvation of a person. Oxygen has a strong toxic effect on the central nervous system and, more specifically, on the brain. Symptoms of poisoning appear very quickly.
Oxygen concentration
Hyperoxia is oxygen poisoning that occurs when breathing a gas mixture that includes air under high pressure. Hyperoxia can occur when using a regeneration unit during oxygen decompression with an increase in dose due to oxygen therapy, when using artificial origin of breathing gases and oxygen devices. If volumeoxygen is increased, the respiratory organs and nervous system are activated.
Oxygen can be in one of four concentrations:
- Liquid. Transient oxygen is in a liquid state, it occurs only when it is cooled to a temperature of -183 ° C. Thus, it becomes faint with a pale azure color, which is in demand in the pharmaceutical industry, construction and chemical industries. Cylinders with weak oxygen, under high pressure, are used in medical institutions, during gas welding, alloy cutting and for the oxidation of various elements in numerous syntheses. With the invention of the cylinder pressure valve, the air is reduced and the solution passes through the oxygen gas.
- Crystals. Cooling down to -223 °C, the air solidifies with the formation of dark blue crystals.
- Gas. The exchange of oxygen in the gas occurs with an increase in the temperature of the previously noted values.
- Plasma. Under circumstances of extreme temperature with continuous air pressure, it can be plasma.
The amount of free air in the atmosphere is above 20%. Oxygen is an essential component of any living cell.
What does hyperoxia mean?
The proportion of oxygen in the air is no more than 21%, its concentration is favorable for human breathing. Hyperoxia is poisoning with active oxygen. It occurs as a result of breathing an oxygen-containing gas mixture (air) at high pressure. Symptoms of oxygen poisoning vary.
Physical and physiological basis of breathing
A simple form of respiratory function looks like this: when inhaled through the lungs, air penetrates into the follicular film, which, in turn, is associated with hemoglobin and red blood cells. The delivery of oxygen to tissues is due to the work of red blood cells. They restore hemoglobin, delivering oxygen, and in addition, carbon dioxide. Subsequently, hemoglobin returns to the lungs, it is secondarily oxidized, increasing the concentration of carbon dioxide. Its excess is eliminated during exhalation.
Excess oxygen leads to a change in metabolism. As a result, the process of gas transfer stops, cell membranes of various tissues and organs are damaged. Intoxication with pure oxygen increases due to the high level of carbon dioxide in the body, harmful inclusions in the respiratory system, overheating, hypothermia and serious intellectual work. In the presence of an inert gas, oxygen poisoning may be most severe.
Poison Form
Hyperoxia can occur in three forms:
- vascular;
- convulsive;
- pulmonary.
Vascular is dangerous, occurs when the pressure of the respiratory system is high. It is characterized by acute dilatation of blood vessels, a decrease in heart rate and blood pressure. There may be hemorrhages in the mucous membranes and skin. A sudden drop in blood pressure can lead to cardiac arrest and death. First aid withthis form of oxygen poisoning is limited to rapid cessation of breathing. For the next 24 hours, the patient must remain in a dark, well-ventilated room, in extremely difficult cases specialist assistance is required.
Convulsive oxygen poisoning in nature appears if the pressure increases by no more than 3 bar. It is characterized by transformations in the nervous system: euphoric induction or indifference, blurred vision, lethargy, and in addition, sweating, increased pallor. Poisoning is accompanied by convulsions, loss of consciousness, severe nausea and dizziness. Secondary seizures can lead to death. In the case of the formation of hyperoxia under water, the possibility of death from drowning is very high. As a rule, the completion of breathing with a strong air flow leads to a stop of convulsions and a return to consciousness. In order to fully restore the state, sleep is needed.
A form of pulmonary hyperoxia occurs with the smallest excess of partial pressure. It is characterized by a defect in the lungs and respiratory tract. First of all, there is dryness in the throat, the nasal mucosa swells, and a feeling of congestion appears. Subsequently, coughing occurs, it continues to increase, accompanied by characteristic sensations in the chest, the body temperature rises. If intoxication persists, hemorrhage will occur in the back and brain, intestinal tract, lungs, liver and heart. Due to respiratory arrest, the symptoms decrease within a few hours, completely disappear within 2-4 days.
What causes hyperoxia?
Liquid oxygen poisoning is inevitably accompanied by a pathology of oxygen metabolism in organs and tissues. Oxygen poisoning in nature begins with a latent period. Its symptoms are associated with an increase in partial pressure in the respiratory system, which occurs almost instantly. Conditions favorable to early hyperoxia are active mental overload, secondary heating, hypothermia, the presence of an inert gas.
Forms and symptoms
When oxygen poisoning occurs, the symptoms may vary. It all depends on the concentration of the gas.
Oxygen poisoning in nature or under water can be expressed by similar signs:
- Vascular form. With such oxygen poisoning, the symptoms are the most dangerous for a person's well-being. Signs of this form of poisoning: an increase in blood vessels rapidly reduces blood pressure, cardiac activity generates hemorrhages in the skin and mucous layers. With a sudden drop in blood pressure, absolute cardiac arrest and death can occur.
- Convulsive form. Oxygen intoxication in this form can be traced due to an increase in pressure, which is not higher than three bar. This is accompanied by subsequent signs: excessive lethargy, high sweating, progressive pallor, vomiting, high nervousness, peripheral vision pathologies, hallucinations (unusual sounds), tingling sensation in the muscles. The nervous system responds to hyperoxiaeither absolute indifference or euphoria. With an increase in hyperoxia, frequent seizures, fainting, convulsions, deafness and severe nausea are noted.
- The third type of condition is completely identical to an epileptic seizure: it comes on suddenly and does not combine any additional functions. Secondary epileptic seizures and convulsions can cause respiratory arrest and death.
- The pulmonary form of oxygen poisoning results in the lowest values of excess partial pressure. The symptomatology of these forms of hyperoxia is associated with a defect in the respiratory tract and lungs. This form is accompanied by a dry throat, severe swelling of the nasal mucosa (giving rise to a feeling of fullness), incessant coughing (accompanied by chest pain), and a significant increase in temperature.
With persistent poisoning, there are multiple hemorrhages in the brain and spinal cord, including the heart muscle, intestinal tract, liver and lungs.
Primary signs of hyperoxia
First of all, hyperoxia begins to affect all the limbs and muscles of the face (especially the lips), the eyelids begin to twitch incessantly. Then the person experiences a feeling of anxiety. Shortly thereafter, convulsions and fainting appear. In case the air supply stops, attacks become more frequent.
First Aid
If the victim has a convulsive form of hyperoxia, you must prevent him from falling onto a hard surface. During the first 24 hours, he is placed inwarm, shaded and well-ventilated area. In case of severe oxygen toxicity, the affected person should seek immediate medical attention. If hyperoxia occurs underwater, the patient must be brought back to consciousness, as there is a high risk that he will simply choke. An experienced instructor provides assistance and supplies oxygen-reduced air.
Procedure of actions
An individual with signs of hyperoxia should immediately reduce the depth of inhalation and switch to apnea. For breathing, he is given gas with a reduced volume of oxygen.
In case of oxygen poisoning in the vascular form, the patient needs an early transition to breathing air. For the next 24 hours, he is placed in a darkened and thoroughly ventilated room. In case of severe oxygen poisoning, the victim should immediately go to the doctor. The results of the pulmonary form of hyperoxia also disappear completely after a couple of days.
Conclusion
Poisoning by pure oxygen is a very dangerous condition that can cause a tragedy. In order not to become a victim of this, a number of inalienable rules should be observed. Before deep diving, you need to carefully control the technical condition of the equipment, and in addition, the marking of regulators and cylinders. It is strictly forbidden to exceed the maximum stay at depth. Having discovered the occurrence of unusual signs, the scuba diver should immediately go to the decompression chamber, because this maydepend on his life.
