I. What is hyperbaric oxygen therapy
Hyperbaric oxygen therapy is a method of treating diseases by inhaling pure oxygen or oxygen at a pressure higher than one atmosphere.
Two, hyperbaric oxygen therapy mechanism
1. Hyperbaric oxygen can improve the oxygen content of the body
(1) Improve blood oxygen tension: blood carries oxygen in two ways, one is “combined oxygen”, every 100ml of blood hemoglobin combined with about 18.2ml of oxygen. The second is “dissolved oxygen”, which can dissolve 0.3 ml of oxygen per 100 ml of blood under normal pressure. It can be seen that the normal state carries oxygen mainly in the form of bound oxygen, while dissolved oxygen is an important way in the delivery process.
When the partial pressure of oxygen reaches 200mmHg, the saturation of hemoglobin reaches 100%, so the increasing oxygen tension of blood under high pressure is mainly increased by “physical dissolved oxygen”, such as the physical dissolved oxygen under 4.0 atm is completely enough for the physiological metabolic needs of body tissues, even without hemoglobin, it will not die.
(2) Increase the oxygen content and oxygen reserve of tissues: the oxygen consumption of tissues under normal condition is 3~4ml/min/kg, while the oxygen content (oxygen reserve) of tissues is 13ml/kg (13ml/kg) of tissues, at this time, if the circulation is completely blocked, the oxygen reserve of tissues is only enough to maintain the metabolism for 3~4 minutes, otherwise the tissues will die due to lack of oxygen. But in the hyperbaric state is different, such as at 3.0 atm (0.3 MPa), the oxygen reserve of the tissue can reach 53 ml/kg (53 ml/kg), so that the safety time limit of blocking the circulation can be extended to 8-12 minutes.
(3) Improving blood oxygen diffusion rate and increasing the effective diffusion distance of blood oxygen: The greater the pressure difference, the greater the diffusion volume per unit time and the greater the diffusion distance. It is like the higher the pressure of the water pipe, the more water flows out per unit time, and the farther the distance of the water jet. When blood flows through the capillaries of the tissue, oxygen always diffuses from the side with high tension to the side with low tension, because the oxygen tension in the capillaries is much higher than the oxygen tension in the tissue, so the place near the capillaries gets oxygen supply first, the further the distance the oxygen tension is lower, and the relative oxygen supply gets gradually reduced. Under normal condition, the effective diffusion radius of oxygen is 30 microns, and at 3.0 atm the effective diffusion radius of oxygen is up to 100 microns.
2.The effect of hyperbaric oxygen on vasoconstriction and the effect on collateral circulation
(1) Vasoconstriction: Oxygen can cause vasoconstriction, which is usually proportional to the oxygen partial pressure, but the decrease in blood flow caused by vasoconstriction can never offset the increase in blood oxygen content. The unfavorable aspect of this constriction results in reduced blood flow and reduced blood supply to local tissues. On the positive side, the vasoconstriction results in decreased permeability of the vessel wall, reduced exudation, and reduced edema, thus increasing the effective diffusion distance of oxygen and ensuring that tissue cells far from the capillaries also receive adequate oxygen supply.
(2) Effect on collateral circulation: Hyperbaric oxygen can promote the growth and division of fibroblasts and the formation of collagen fibers, which are the basis of blood vessel formation, and therefore can promote the re-establishment of collateral circulation.
3, hyperbaric oxygen can inhibit the growth and reproduction of anaerobic bacteria
The so-called anaerobic bacteria refers to certain bacteria can only grow and reproduce in the absence of oxygen or less oxygen, such as the common clinical Bacillus pneumoniae, in the state of hyperbaric oxygen due to the increase in oxygen content in the body, so can inhibit or kill anaerobic bacteria, the clinical use of this is used to treat gas gangrene, tetanus, actinomycosis, periodontal disease, etc..
In addition, hyperbaric oxygen can also enhance the activity of phagocytes and promote the absorption of necrotic tissue, which is conducive to tissue healing.
4.Hyperbaric oxygen can enhance the efficacy of radiotherapy and chemotherapy on malignant tumors
The mechanism of hyperbaric oxygen as an adjuvant therapy for tumor treatment is not very clear, there are three main views as follows.
(1) Hyperbaric oxygen can make tumor cells become more sensitive to radiotherapy and chemotherapy.
(2) Hyperbaric oxygen can inhibit the activity of some enzymes of tumor cells.
(3) The toxic effect of hyperbaric oxygen on tumor cells can directly destroy tumor cell membrane proteins and enzymes.
(4) Hyperbaric oxygen has a quality effect on radioactive injury and can promote tissue healing, such as radioactive osteomyelitis, radioactive cystitis, radioactive skin ulcers, etc.
(5) Hyperbaric oxygen can make the air bubbles imprisoned in the body become smaller or disappear
According to the gas law, high pressure is conducive to the dissolution of gas bubbles in tissues, which can reduce the volume of gas bubbles in the body, and finally the gas completely dissolved in tissues can be circulated to the lungs with blood, and finally discharged from the body with breathing, precisely according to which it can be used to treat decompression sickness and gas embolism.
6.Hyperbaric oxygen can improve microcirculation
Microcirculation is the place where oxygen and nutrients in the blood are exchanged with metabolites in the tissues, and it is the smallest functional unit of the body, which is directly involved in the metabolism of substances, so it is of great significance.
(1) Hyperbaric oxygen increases the deformability of red blood cells, thus enabling them to pass smoothly through capillaries smaller than their own diameter.
(2) Hyperbaric oxygen prevents platelet aggregation and prolongs the clotting time by inhibiting the blood clotting system, thus preventing the formation of blood clots.
(3) Hyperbaric oxygen accelerates blood flow and prevents the aggregation of red blood cells.
(4) Hyperbaric oxygen can reduce the viscosity of blood.
7.Hyperbaric oxygen can regulate nerves and adjust immunity
Through the regulation of the nervous system, it enhances the body’s defense ability and improves the immunity of the body. In addition, hyperbaric oxygen can enhance the bactericidal properties of white blood cells and the activity of phagocytes.
8. Hyperbaric oxygen can promote the repair of nerve sheath membrane.
III. Main diseases treated by hyperbaric oxygen
(A) Acute indications
1.Acute carbon monoxide and other harmful gas poisoning.
2.Acute ischemic-hypoxic diseases: such as brain dysfunction caused by electric shock, drowning, asphyxiation, sudden death, surgery or anesthesia accident, etc.
3.Acute retinal artery (vein) embolism.
4.Acute spinal cord and peripheral nerve injury.
(B) Non-acute indications
1.ischemic and hypoxic cerebrovascular diseases: cerebral infarction, cerebral atherosclerosis, cerebral blood supply deficiency, senile dementia, sleep disorders (insomnia or excessive sleep).
2, hypoxic cardiovascular disease: coronary heart disease, arrhythmia, myocarditis.
3, traumatic brain injury, concussion, postoperative cerebrovascular disease.
4, viral encephalitis, facial nerve palsy.
5, fracture and poor healing, chronic osteomyelitis.
6, peripheral vascular diseases: vasculitis, chronic skin ulcers, diabetic foot.
7, sudden deafness, tinnitus.
8, Fundus disease: central plasma retinal choroiditis, macular degeneration, diabetic fundus disease, optic neuritis.
9.Children’s developmental delay, autism, cerebral palsy and neonatal asphyxia and hypoxia.
(C) health care role
1, subhealth and chronic fatigue syndrome: such as headache and dizziness, insomnia and dreaminess, mental depression, general weakness, memory loss, inattention, etc.
2, cardiovascular and cerebrovascular diseases regularly do hyperbaric oxygen has a certain preventive health care effect.
3.Doing hyperbaric oxygen before high school entrance examination, middle school entrance examination or graduate school can effectively regulate nerves and improve study efficiency.