Hyperbaric oxygenation

Hyperbaric oxygenation - assignment of 100% O2 for several hours in a sealed chamber with a pressure of more than 1 atm, which is gradually reduced to atmospheric pressure. To divers this treatment is carried out, first of all, with decompression sickness and arterial gas embolism. The faster the therapy is started, the better the result. Untreated pneumothorax should be drained before or during recompression.

The goals of recompression therapy are to increase the solubility and delivery of O2, to accelerate the leaching of N, to reduce the size of gas bubbles and, in rare cases, associated with carbon monoxide poisoning, to reduce the half-life of CO2 and to reduce the degree of tissue ischemia. Hyperbaric oxygenation (HBO) is also used for other medical indications not related to snorkeling.

Hyperbaric oxygenation *

Confirmation data	Violations
A sufficient number of	Arterial gas embolism Poisoning CO (heavy) Clostridial infection Decompression disease Osteoradionecrosis Poorly healing wounds (including skin grafts)
A small amount of	Anemia (severe) with hemorrhagic shock Burns Intracranial abscess with actinomycosis Necrotizing fasciitis Radiation damage to soft tissues Refractory osteomyelitis Syndrome of prolonged crushing with compartment syndrome Healing of wounds in ischemic limbs
Little or no	Dementia Multiple sclerosis

Hyperbaric oxygenation is the basis for the treatment of decompression-related decompression injuries and arterial gas embolism. It is also being used for many other diseases. The effectiveness of hyperbaric oxygenation is most clearly proved for a small number of states. Relative contraindications include chronic pulmonary dysfunction, sinus disease, diseases with convulsive syndrome and claustrophobia. Pregnancy does not serve as a contraindication.

Patients tolerate recompression relatively well, it must be started immediately, even with a low probability that it will speed recovery. Recompression can help, even if it is started with a great delay, after 48 hours after surfacing.

HBO cameras are single and multi-seat with seats for several patients on wheelchairs or in a chair, as well as for an accompanying health worker. Although the costs for single-seat HBO cameras are significantly smaller, they do not provide access to the patient during treatment. Use them for patients in critical conditions, which may require additional interventions, is undesirable.

Most divers, medical workers, rescuers and policemen in popular zones for scuba diving should have information about the location of the nearest HBO recompression chamber, the shortest way to it and a contact phone for urgent consultation.

[1], [2], [3], [4], [5], [6]

Recompression protocols

Pressure and duration of treatment ("immersion") are usually determined by specialists of a recompression facility. Treatment is performed 1 or 2 times a day for 45-300 minutes, until the symptoms decrease; for 5-10 minutes do "air breaks" to reduce the risk of toxic effects of O2. The pressure in the chamber is usually maintained between 2.5 and 3.0 atm, but patients with life-threatening neurological symptoms developed as a result of gas embolism often begin treatment with a pressure of 6 atm to quickly squeeze gas bubbles in the brain.

Although recompression therapy is usually carried out using 100% O2 or compressed air, special gas mixtures (for example, helium / O or nitrogen / O in non-atmospheric proportions) are possible, which are especially indicated if the diver was immersed in an unusual gas mixture or depth / duration of immersion were extraordinary.

Patients with residual neurologic deficit are shown repeated periodic hyperbaric oxygenation; To achieve maximum recovery, it may take a course of several days or weeks.

Complications and contraindications for hyperbaric oxygenation

Recompression therapy can cause problems similar to those that occur in barotrauma, including reversible nearsightedness, barotrauma of the ears and paranasal sinuses. In rare cases, barotrauma of the lungs, pulmonary intoxication of O2, hypoglycemia or convulsions is possible. The risk of complications associated with barotrauma or O2 CNS damage is elevated in patients with seizures, pneumothorax, or thoracic operations in the anamnesis. Sedatives and opioid analgesics can lubricate symptoms and cause respiratory failure, their use is best avoided or used only in the smallest doses.

Relative contraindications include COPD, upper respiratory tract infection or paranasal sinuses, recent surgery or ear trauma, fever and claustrophobia.

[7], [8], [9]