Hyperbaric medicine

Hyperbaric oxygenation ( HBO) (Alternative names: hyperbaric oxygen therapy, HBO therapy, English: hyperbaric oxygen therapy; HBO2, HBOT ) is a form of therapy in the medically pure oxygen under increased atmospheric pressure ( the air pressure is higher than the normal atmospheric pressure) for defined time periods and intervals in patients by inhalation applies.

• 2.2.1 pressure-volume relationship
• 2.2.2 partial pressure principle

• 3.1 Basics
• 3.2 Patient information for treatment with HBO
• 3.3 Applications of hyperbaric oxygen therapy 3.3.1 Indications with urgent advice on the application of HBO
• 3.3.2 Indications with recommendation on the use of HBO

• 5.1 Germany 5.1.1 Statutory health insurance
• 5.1.2 Private health insurance

• 7.1 Original works and studies
• 7.2 Overview of work
• 7.3 reviews

Implementation

The increased ambient pressure (gauge pressure) is typically used established through a pressure chamber. There are principally distinguished:

• Breathing through an air- tight -fitting face mask
• Breathing through a so-called head tent
• Breathing through a tube ( endotracheal tube, Pharyngealtubus ) The implementation of hyperbaric oxygen therapy is thus possible even in mechanically ventilated patients. For this purpose, however, specially certified respirators are required.

Principle

Physical principles

Several physical principles underlying the invention and application of hyperbaric oxygen therapy. Hyperbaric oxygen therapy is based on the physical laws of gases. Here is the gas law of Henry of particular significance for the use of oxygen in the pressure:

Solubility of gases in liquids

The physical Henry's Law describing the solubility of gases in liquids. In this case, the amount of dissolved gas in a liquid is proportional to the load ends of the liquid pressure in the system of gas and liquid. Concrete, this means that you can solve more gas in a liquid the more, the higher the pressure.

Transfer to living beings

Because blood is a fluid without a doubt, the Henry's law applies fully. Within the hyperbaric oxygen therapy, the patient is treated with 100% pure oxygen, which is enriched by Henry in body fluids in accordance with the applied pressure. Humans oxygen is transported mainly by chemical bonding to the hemoglobin contained in red blood cells. The number of red blood cells, or more precisely the amount of hemoglobin is therefore critical for the oxygen carrying capacity of blood. Oxygen is but after Henry - usually in small scale - in the form of physically dissolved in the blood and in all body fluids. The amount of physically dissolved oxygen is dependent on the oxygen partial pressure in the breathing air. Since the red blood cells and hemoglobin are already a standard air (21% oxygen), or saturated capacity of 95 to 100% ( oxygen saturation ), an increase of the blood oxygen content by the oxygen bound to hemoglobin is not practically possible. The increase of the oxygen content ( partial pressure ) in the air from 21 to 100% ( about five times), causes a proportional increase in the amount of oxygen dissolved in the blood. A further increase of the oxygen partial pressure is possible by increasing the ambient pressure. Breathe man in a pressure chamber in pure oxygen at a pressure of 2.5 bar, for example, gets about 20 times the amount of oxygen in solution in the blood. Based on the total oxygen content in the blood of the increase effect is not large, but significant: this way, the possible diffusion path for oxygen in the capillary (the distance between the blood vessel and cell so ) of typically 64 microns is increased to 247 microns which in circulatory disorders and other oxygen deficiency of meaning is:

See also Oxygen Window

Pressure-volume relationship

This relationship is governed by the law of Boyle -Mariotte, which states, in essence, that the volume ( volume) of a gas decreases with increasing pressure. Or at decreasing pressure, the volume increases ( volume). Conversely, also, that decreases with increasing volume of the pressure increasing or decreasing in volume, the pressure.

Partial pressure principle

This principle is based on the Law on the partial pressures of John Dalton. Dalton noted that the total pressure of a gas mixture, such as the normal atmospheric air of the earth, composed of the partial pressures of the individual gases of the mixture.

Application ( indications)

Basics

Hyperbaric oxygen therapy is used worldwide in diseases in which a lack of oxygen is the cause of insufficient healing and the deficiency can be compensated by the use of HBO. There are also some emergency diseases in which oxygen is life-saving. The use of hyperbaric oxygen is based on scientific studies of varying quality. According to the criteria of " evidence based medicine ", there are now numerous studies for various diseases of the highest level of evidence (1a). For more medical conditions, there are studies class 1b and otherwise comprehensive literature, which, as is common practice in medicine, the experience of hyperbaric reproduces. The HBO is consequently recognized and financed world of many national health systems for widening indication catalogs. Yet you shall be liable to the odium of a controversial form of treatment. This is especially true for Germany, but also in other countries and health care systems is the application of HBO is not without controversy. This is due to several factors ( order not care):

Patient information for treatment with HBO

With regard to the scope of the duty of disclosure arises between the hyperbaric oxygen therapy and other medical measures, no difference ( comprehensive information obligation). This includes the information about the situation regarding the reimbursement ( or not taking place reimbursement) by health insurance carriers. The duty of disclosure is to be construed according to the disease being treated image so that treatment alternatives are enumerated. The treatment alternatives include the possibility of observing or no intervention one (see also spontaneous cure rate for the disease tinnitus and sudden hearing loss ).

Applications of hyperbaric oxygen therapy

According to the recommendations of the medical scientific societies for hyperbaric oxygen therapy in Europe and worldwide ( ECHM, EUBS, Society for Diving and Hyperbaric Medicine ( GTÜM ), UHMS ) are due to the following evidence-based scientific studies indications:

Indications with urgent advice on the application of HBO

Indications with a recommendation on the use of HBO

Further indications

Other indications for adjuvant application of HBO are in testing according to scientific standards. A recommendation for the HBO application therefore at present not yet been made by the medical scientific societies.

A "guarantee" a successful improvement or cure is not possible, as with all medical services. In general, the application of HBO as adjuvant to treatment measures otherwise required occurs when these have not been sufficient for treatment success. The Enlightenment in the pressure chamber center also explained the chances of success of HBO, alternative and conventional treatments.

Risks and side effects

As with any medical treatment, there is also the use of HBO risks and side effects. They are rare.

• Barotrauma of the ear drum: This side effect is common. In most cases, however, it is limited to a slight reddening of the tympanic membranes, which heal by themselves within 24 hours. In children ( cf. incidence of middle ear infections ), the frequency of adverse reactions is higher.
• Fire hazards in the pressure chamber: This is especially true for the atmosphere of 100 % oxygen in a Einpersonendruckkammer. In multi-person chamber pressure, the risk is even increased, but de facto insignificant. Respiration takes place in a nearly closed system, the air chamber is made from compressed air and in Germany is a monitoring of the oxygen content of the chamber air is mandatory (must be less than 23%). In the not usual in Germany Einpersonendruckkammern with atmosphere of 100 % oxygen is in addition to a substantial risk of fire in the presence of an ignition source in the chamber above all danger of explosion.
• Seizure ( as in epilepsy) of the brain. It is formed by the action of a high " dose " of oxygen. This side effect is very rare ( 1 in 3388 occurrence treatments, equivalent to 0.03 % treatment- number-related ), but as any seizure of the brain in principle dangerous (risk of injury due to uncontrolled movements, laying of airways ). In general, oxygen toxic seizures are but consequences. The probability of occurrence of seizures under HBO conditions depends on the one hand on the health of the patient and on the other hand by the oxygen dose and time of exposure to high oxygen concentrations. However, a prediction based on empirical data or calculations is not possible because of unseen contexts a high intra-and inter-individual variability exists.
• Myopia by the action of oxygen. It is also formed by the action of high " doses " of oxygen. The myopia is mild and regresses completely. When using a headset, tent, the probability of occurrence is higher, but this side effect concerns as much as 50 % of patients treated with more than 15 units HBO therapy (but only very few noticed ).
• Lung damage by oxygen (ALI and ARDS) are possible. It is caused by the action of a high " dose " of oxygen. The same clinical picture is also known in patients with long-term mechanical ventilation with 100% oxygen. In the hyperbaric oxygen therapy lasting lung damage if used properly, are not expected.
• Nausea, vomiting - rarely possible due to volume change due to pressure, but also by oxygen.

Costs and reimbursement of expenses

Germany

Statutory health insurance

The outpatient treatment with Hyperbaric Oxygen Therapy is not an object of the benefit package of the statutory health insurance funds in ambulatory patient care. Thus, the cost of treatment is usually by the patient are to be borne by ( cost-transfer requests are still made ​​and granted it occasionally ). Billing is based on the rate of doctors as in the treatment of private patients.

Hyperbaric oxygen therapy for items marked in the list of indications listed above with * Indications are taken as part of the inpatient treatment of the statutory health insurance as part of the DRG (G- DRG) on the basis of a positive decision of the Joint Federal Committee ( G- BA). For the diabetic foot syndrome that, according to a ruling by the Federal Social Court ( judgment of 7 May 2013 Az B 1 KR 44/12 R ), also for outpatient treatments. Clinics would have to hyperbaric oxygen therapy as a foreign power " shopping ", unless they have their own pressure chambers. ( This is the rule )

Private health insurance

Private health insurance companies outpatient and inpatient treatments using hyperbaric oxygen therapy on request. The request should ideally include an estimate of the planned treatment. Nearly all German private health insurance, as well as the aid of officials to take over the costs for example, for the indications of acute sudden deafness and acute tinnitus after appropriate inquiry. An entitlement is guided by the existing case law ( Court of Appeal judgments Koblenz and Stuttgart).

Internationally

In contrast to the Federal Republic of Germany, for example, in Switzerland, in the U.S., UK or France, the Hyperbaric Oxygen Therapy part of the benefit package of the statutory health insurance. It should be noted that depending on the insurance type and girders, the indications are significantly wider part than in Germany. In part arise also notable differences. The wider range of reimbursable indications in this context means not that the Hyperbaric Sauerestofftherapie is undisputed in the designated countries.