Oxygen at high partial pressure is toxic. There is poisoning of the body, which causes seizures, similar to an epileptic seizure, which in water leads to drowning, and only the correct behavior during 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 in a gas mixture that includes high-pressure air. Hyperoxia can occur when using a regeneration unit during oxygen decompression with an increase in dose due to oxygen therapy, when using the artificial origin of respiratory gases and oxygen devices. If the oxygen volume is increased, the respiratory organs and nervous system are activated.
Oxygen can be in one of four concentrations:
- Liquid. Transitional oxygen in a liquid state, it arises only when it is cooled to a temperature of –183 ° . Thus, it becomes weak with a pale azure color, which is in demand in the pharmaceutical industry, construction and the chemical industry. Low oxygen cylinders, which are 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 a pressure valve in a cylinder, air is reduced and the solution passes through oxygen gas.
- Crystals. Cooling to –223 ° , the air hardens with the formation of dark blue crystals.
- Gas. The exchange of oxygen in the gas takes place with increasing temperature of the previously noted values.
- Plasma. In circumstances of the highest temperature with continuous air pressure, it can be a plasma.
The amount of free air in the atmosphere is above 20%. Oxygen is an integral component of any living cell.
What does hyperoxia mean?
The proportion of oxygen in the air is not more than 21%, its concentration is favorable for human breathing. Hyperoxia is poisoning with active oxygen. It occurs due to breathing of an oxygen-containing gas mixture (air) at high pressure. Symptoms of oxygen poisoning are different.
Physical and physiological basis of respiration
A simple form of respiratory function looks like this: when inhaled through the lungs into the follicular film, air penetrates, which, in turn, is associated with hemoglobin and red blood cells. The delivery of oxygen to the tissues is due to the work of red blood cells. They restore hemoglobin, delivering oxygen, and in addition, carbon dioxide. Subsequently, the return to the lungs of hemoglobin, it is oxidized again, increasing the concentration of carbon dioxide. Its excess is eliminated during the exhalation period.
Excess oxygen leads to a change in metabolism. As a result, the gas transfer process stops, cell membranes of different tissues and organs are damaged. Pure oxygen intoxication is increased 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 pronounced.
Form of poisoning
Hyperoxia can occur in three forms:
- vascular;
- convulsive;
- pulmonary.
Vascular is dangerous, occurs with high pressure of the respiratory system. 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 sharp decrease in blood pressure can lead to cardiac arrest and death. First aid with this form of oxygen poisoning is limited to a quick stop of breathing. Over the next 24 hours, the patient should be in a dark, well-ventilated room, in extremely difficult cases, the help of a specialist is required.
Convulsive oxygen poisoning in nature appears if the pressure rises no more than 3 bar. It is characterized by transformations in the nervous system: euphoric induction or indifference, impaired vision, lethargy, and in addition, sweating, increased paleness. Poisoning is accompanied by convulsions, loss of consciousness, severe nausea and dizziness. Secondary cramps can cause death. In the case of the formation of hyperoxia under water, the possibility of death from drowning is very high. As a norm, completion of breathing with a strong flow of air leads to a stop in convulsions and a return to consciousness. In order to fully restore the state, sleep is necessary.
A form of pulmonary hyperoxia occurs with the least 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, a feeling of congestion appears. Subsequently, coughing occurs, it continues to increase, accompanied by characteristic sensations in the chest, 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 are reduced for some hours, completely disappear within 2-4 days.
What causes hyperoxia?
Poisoning with liquid oxygen is inevitably accompanied by 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 conducive to early hyperoxia are active mental overload, secondary heating, hypothermia, the presence of inert gas.
Forms and Symptoms
When oxygen poisoning has occurred, the symptoms may be different. It all depends on the concentration of 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 the well-being of a person. 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 the following symptoms: excessive lethargy, high sweating, progressive pallor, vomiting, high nervousness, peripheral vision pathologies, hallucinations (unusual sounds), a tingling sensation in the muscles. The nervous system responds to hyperoxia with either absolute indifference or euphoria. With increased hyperoxia, frequent seizures, fainting, cramps, deafness, and severe nausea are noted.
- The third type of condition is completely identical to an epileptic seizure: it occurs unexpectedly and does not combine any additional functions. Secondary epileptic seizures and convulsions can cause respiratory arrest and death.
- The pulmonary form of oxygen poisoning leads to 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 dry throat, severe swelling of the nasal mucosa (giving rise to a feeling of fullness), continuous coughing (accompanied by pain behind the sternum), a significant increase in temperature.
With constant poisoning, multiple hemorrhages are observed 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), and the eyelids twitch continuously. Then the person experiences a feeling of anxiety. Soon after, convulsions and fainting appear. If the air supply stops, attacks become more frequent.
First aid
If the victim has a convulsive form of hyperoxia, you must prevent it from falling onto a hard surface. During the first 24 hours it is placed in a warm, shaded and well-ventilated area. In case of severe oxygen toxicity, the victim should immediately consult a doctor. If hyperoxia occurs under water, the patient should be brought to consciousness, as there is a big risk that he will simply choke. An experienced instructor helps and delivers air with a reduced oxygen content.
Procedure
An individual with signs of hyperoxia should immediately reduce the depth of inspiration and switch to respiratory arrest. For breathing, he is given gas with a reduced amount of oxygen.
In case of oxygen poisoning in a vascular form, the patient needs an early transition to breathing air. Over the next 24 hours, he is placed in a darkened and thoroughly ventilated room. In case of serious oxygen poisoning, the victim should immediately go to the doctor. The results of pulmonary hyperoxia also disappear completely after a couple of days.
Conclusion
Pure oxygen poisoning is a very dangerous condition that can cause a tragedy. In order not to fall prey to this, a number of inalienable rules should be followed. Before deep diving, it is necessary to carefully monitor the technical condition of the equipment, and in addition, the marking of the regulators and cylinders. It is strictly forbidden to exceed the maximum stay in depth. Having discovered the occurrence of unusual signs, the diver should immediately go to the decompression chamber, because his life may depend on this.