Hyperbaric oxygen therapy has a good curative effect and is widely used in clinic treatment of small animals, whether as emergency therapy or adjuvant therapy in medicine and surgery.
In veterinary clinics, hyperbaric oxygen may not be used to its full potential because owners and doctors do not know much about their efficacy.
HBOT was used in humans as early as 1895, and Scottish physicians applied this treatment to carbon monoxide poisoning.
The first formal clinical application was in 1930 by the Brazilian physician Alvaro Osorio de Almeida.
By 1950, there had been sufficient researches on HBOT to show widespread clinical applications, and in the late 1990s, HBOT began to appear in brain injury applications.
Four gas laws (Dalton's law, Boyle's law, Graham's law, Henry's law) can help you better understand the therapeutic effect of hyperbaric oxygen: sick animals receive 100% pure oxygen, oxygen partial pressure increases, and the density and dissolution rate of oxygen are greatly increased.
Oxygen transport is based on three factors: cardiac output, arterial oxygen content, and blood flow. Arterial oxygen content can be calculated from hemoglobin concentration, hemoglobin saturation, and arterial oxygen partial pressure: Cao2=(1.36*Hb*SaO2)+(0.003*Pao2)
There is usually very little dissolved oxygen in the blood, and in the case of hyperbaric oxygen (2 absolute barometric pressures), the oxygen dissolved into the blood is 15 times in the normal barometric pressure.
This is to increase the oxygen carrying capacity of the blood without increasing hemoglobin. Therefore, when the local tissue and capillaries are compressed and the blood vessels are reduced, the compressed tissue has a greater chance to obtain more oxygen due to the effect of pressure.
Most veterinarians use hyperbaric oxygen equipment of 2.0-3.0 ATA. However, low-pressure therapy is usually set at an absolute pressure of 1.5-2 ATA. When low-pressure therapy is carried out, the treatment time is longer.
The average treatment time under 2.0ATA is 45 to 60min. Treatments are repeated every 8 to 12 hours on average for small animals and every 24 hours for larger animals. Of course, it also depends on the severity of the disease.
When animals are placed in hyperbaric chambers, the oxygen chambers begin to increase the pressure, and the air in the oxygen chamber is gradually replaced by pure oxygen. The composition of pure oxygen absorbed by the animal under normal air pressure increases, and the gradually increased oxygen molecules cause oxygen partial pressure to increase (Dalton's law).
So when the animal breathes, the partial pressure of oxygen to the alveoli increases, which increases the oxygen concentration in the alveoli (Boyle's law), and the capillaries of the lungs get more oxygen.
Because the law of gas movement is that gas moves from high pressure to low pressure (Graham's law), an increase in oxygen partial pressure causes an increase in the density of oxygen molecules, which diffuses into the alveolar epithelium and then into the blood.
High density and high pressure oxygen increases the solubility of oxygen in the blood (Henry's law), causing a significant rise in arterial oxygen partial pressure.
Likewise, a high partial pressure of oxygen creates a pressure gradient that determines the direction (amount and rate of oxygen dispersion) of oxygen in the blood through the capillary endothelium, intercellular substance, and intercellular compartment.
Finally, the significantly increased partial pressure of oxygen enters the tissue cells through the vascular interstitium.