Decompression chamber (recompression and hyperbaric therapy)

Design and main components

Chambers vary by size and function but share basic elements that permit safe pressurization, ventilation, and patient monitoring. Two broad categories are recognized:

• Monoplace chambers — designed for a single patient, typically pressurized with pure oxygen and used for many HBOT treatments.
• Multiplace chambers — larger units that accommodate several people simultaneously, often pressurized with air while patients breathe oxygen through masks or hoods; these are common for diving emergencies because attendants can enter with the patient.

Key components include a pressure vessel, air and oxygen supply systems, pressure-control valves, intercoms, seating or stretchers, medical monitoring equipment, and safety systems to manage fire and gas contamination risks. Operators control pressure in terms of atmospheres absolute (ATA) or equivalent depths and follow established schedules for compression and staged decompression.

Medical and diving uses

The primary diving-related indication is treatment of decompression sickness (the bends) and arterial gas embolism, where recompression helps reduce bubble size and supports inert gas elimination. Chambers are also widely used for clinical hyperbaric oxygen therapy, which can assist in the treatment of conditions such as carbon monoxide poisoning, certain non-healing wounds, radiation tissue injury, and gas gangrene. In many rescue situations, surface decompression with a chamber is employed instead of lengthy in-water decompression stops—allowing faster, safer treatment in cold or hazardous surface conditions.

Procedure and typical practice

Treatment begins with medical assessment and placement inside the chamber. For diving injuries, the chamber is compressed to a target pressure and the patient breathes oxygen according to a protocol that balances oxygen benefit with the risk of oxygen toxicity. Sessions can include multiple periods of oxygen breathing interleaved with air breaks, and total treatment time varies with the severity of symptoms and response. Multidisciplinary teams monitor vital signs, provide supportive care, and adjust the pressure schedule as needed.

Safety, contraindications and limitations

While effective, chambers carry specific risks. Elevated oxygen concentrations increase fire hazard, so strict oxygen safety protocols are essential. Barotrauma to the ears, sinuses or lungs, claustrophobia, and ear or sinus blockages are common complications; an untreated pneumothorax is a serious contraindication to pressurization. Properly trained operators and medical oversight are required to identify risks and manage complications. Availability and cost can limit access in some regions.

History and context

The concept of using elevated pressure for medical or diving purposes developed alongside advances in diving and aerospace medicine. Early forms of pressurized chambers evolved from diving bells and simple pressure vessels; over time, clinical hyperbaric medicine became an established specialty, and recompression chambers became standard equipment on many vessels and at specialized treatment centers. Today, chambers bridge emergency diving care and a range of therapeutic applications, with standardized protocols and international guidelines guiding safe and effective use.