decompression chamber
A decompression chamber is an airtight and pressure-tight container for the controlled increase and decrease of the ambient pressure ( compression and decompression ). It is usually made of steel or composites , rarely tear-resistant textiles for limited pressure applications. Therapeutic (hyper) pressure chambers (HBO, hyperbaric oxygenation or oxygen therapy) are used for the medical treatment of various illnesses, including the treatment of decompression sickness in divers and caisson workers . The decompression chamber is also used by professional divers after a mission to adjust to the atmospheric pressure in accordance with regulations in order to prevent decompression sickness. The stay in the decompression chamber can take several hours, days or weeks after long and deep diving missions.
construction
A modern pressure chamber usually consists of a main chamber, in which the treatment takes place, and a secondary chamber, which serves as a person lock . In many cases, there is also a very small chamber with only a few liters of content, which is used to transfer medical instruments or medication in and out.
The modern pressure chambers for the application of hyperbaric oxygen therapy (HBO) differ greatly from the narrow one-person chambers from the early days of hyperbaric medicine. They usually offer space for twelve or more seated people, sometimes even for patients lying in hospital beds. Equipment, medical technology and clothing must function in a fire-safe manner at increased air pressure and up to around nine times the oxygen partial pressure . For their safety, patients are monitored with video cameras, intercom systems and sensors, and medical personnel can enter or exit the main chamber via the lock during an ongoing treatment.
Today, unlike the first of their kind, pressure chambers are usually not walled-in rooms, but a tightly closing, pressure-resistant steel vessel. Mobile pressure chambers are driven, for example, to a diving mission or the location of a mining accident. Some of the pressure chambers are mounted on special ships that are specially designed and built for long offshore diving missions.
treatment
Accidental divers and hyperbaric workers must get into a decompression chamber as quickly as possible to prevent permanent damage. As the pressure in the decompression chamber is slowly increased and then decreased again, the increased nitrogen content in the tissue and blood can be excreted more quickly. If this does not succeed, there is a high probability that gas bubbles will develop in the tissue, since the nitrogen passes from the solution in the body into the gas phase and bubbles out due to the lower ambient pressure on the surface . The resulting vesicles can tear tissue, clog important blood vessels and cause the tissue behind to die.
The standard therapy scheme is the so-called "problem wound scheme". It includes a pressure increase with "normal" air to 1.4 barg (bar overpressure), which corresponds to a water depth of 14 meters. Here the patient receives 100% medical oxygen for a total of 90 minutes. This is inhaled in blocks of 20 minutes, with a 5 to 6 minute break. The break is necessary to prevent an oxygen spasm, as the excess pressure means that a lot of oxygen is absorbed into the blood and this can lower the spasm threshold. Depending on the compression speed, this type of therapy lasts between 140 and 160 minutes on average.
In the event of diving accidents, the pressure in decompression chambers is usually increased and then decreased according to a so-called US Navy decompression table :
- US Navy Table 6
- With normal air, compression goes up to a relative pressure of 1.8 bar within 20 minutes (corresponds to a diving depth of about 18 meters ). Then the breathing gas is switched from air to oxygen. After 75 minutes, it is decompressed to 0.91 bar (9.1 meters) and, after a further 150 minutes, it is finally slowly reduced to normal pressure. A decompression chamber trip according to US Navy Table 6 usually takes four hours and 45 minutes and can be extended if necessary. This procedure is used to treat type II decompression sickness.
- US Navy Table 5
- The procedure is very similar to Table 6, but takes less time. At a relative pressure of 1.8 bar it is only held for 45 minutes and at 0.91 bar only for 30 minutes. A decompression chamber trip according to US Navy Table 5 usually takes two hours and 40 minutes. This procedure is used to treat mild type I decompression sickness.
- US Navy Table 9
- It is compressed to a relative pressure of 1.4 bar (14 meters) and pure oxygen is breathed at this pressure for 100 minutes. Then a slow decompression is initiated to normal pressure. The entire decompression chamber trip takes a little more than two hours. This procedure is mostly used in repeated repetitions for the treatment of decompression sickness type III.
The following clinical pictures can be treated in a pressure chamber:
- decompression sickness
- Carbon monoxide poisoning as a result of smoke gas formation in incomplete combustion processes (fires; defective heating systems; indoor barbecues; shishas )
- Gas fire - infection
- arterial gas embolism
- Diabetic foot syndrome - chronically resistant to therapy despite extensive therapy
- Bone necrosis
- Bone marrow edema syndromes
- Ahlbäck's disease
- Chronic therapy-resistant osteomyelitis , otitis externa necrotic (maligna)
- Sudden hearing loss with or without tinnitus,
- acute acoustic trauma, pop trauma
- Effects of radiation on bones, intestines and bladder, etc.
- Crush injuries
- uncontrollable infections
Locations
There are around 30 pressure chambers across Germany, 10 of which are on 24-hour standby. However, these include only 8 pressure chambers with 24-hour readiness that can care for intensive care patients: Murnau , Munich , Berlin , Wiesbaden , Düsseldorf, Gelsenkirchen-Buer, Aachen and Halle . In Switzerland, there are pressure chambers in Geneva and Basel . In Austria there is a pressure chamber in Graz .
The pressure chamber system of the Naval Medical Institute of the Navy in Kiel (move to Hamburg planned) has a special position . The SchiffMedInstM basically also offers 24-hour standby and ventilation capacities, but has not yet been locally connected to a hospital with an intensive care unit. Mainly military diving accidents are treated, but also civilian patients.
The federal teaching and research center of the DLRG operates a decompression chamber with a diving tower underneath in Berlin , in which divers can collect “wet” deep-noise experiences in a safe environment .
See also
Web links
- Directory of treatment pressure chambers for Germany, Austria and Switzerland on the website of the Society for Diving and Hyperbaric Medicine (GTÜM)
Individual evidence
- ↑ a b Tessenberg of Glasow: pressure chamber development , in Divemaster magazine, issue No. 77, MTI Press, Stuttgart.
- ^ Elmer M. Cranton: Hyperbaric Medicine Therapy in a Sechrist Monoplace Chamber. (No longer available online.) September 10, 2012, archived from the original on October 26, 2014 ; accessed on June 27, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ HAUX pressure chamber , in Divemaster Magazin, issue No. 63, MTi-Press, Stuttgart.
- ^ Thomas Kromp , Hans J. Roggenbach , Peter Bredebusch : Practice of diving 3rd edition. Delius Klasing Verlag, Bielefeld 2008, ISBN 978-3-7688-1816-2 , page 191.
- ↑ Regensburg has a pressure chamber again. Mittelbayerische Zeitung , accessed October 4, 2015 .
- ↑ Emergency centers for diving accidents and other (emergency) indications for HBOT. Society for diving and hyperbaric medicine , accessed June 27, 2014 .
- ↑ Switzerland. Society for diving and hyperbaric medicine, accessed June 27, 2014 .
- ↑ Austria. Society for diving and hyperbaric medicine, accessed June 27, 2014 .
- ↑ http://www.y-punkt.de/portal/poc/ypunkt?uri=ci:bw.bwde_ypunkt.archiv.2007&de.conet.contentintegrator.portlet.current.id=01DB131000000001%7C74REWQ220INFO ( page no longer available , Search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
