A hyperbaric chamber is a container big enough to accommodate people while also holding gases at a specific pressure. In this case selected breathing mix is delivered and the internal pressure of the chamber is increased. Chambers come in various sizes, accommodate from one to multiple patients and have attendant staff within the chamber.
Multiplace chambers are made of steel and are usually cylindrical. Trained personnel may accompany the patient during treatment, where they can carefully monitor the patient’s signs and symptoms and give drugs and fluids. Multiplace chambers use an air environment, and patients breathe oxygen or other therapy gases through a face mask, hood or endotracheal tube.
The airlocks, inside the chamber, are independently pressurized to not compromise the pressure in the main chamber. An intercom is available for communicating with anyone in the chamber.
Chambers have been used for centuries, historically since 1662. Wide use of Hyperbaric Oxygen Therapy in clinical cases started in the middle of the 20th century. Intensive research on HBOT took place for almost 3 decades in UK and also, Germany, USA, France and elsewhere. From that point, Hyperbaric Medicine has become a distinct, appreciated and recognized field in Medicine tested on a large number of conditions through the years. There are 14 universally approved indications for HBOT now, while there is ongoing research for its use in other maladies taking into account evidence and its cost effectiveness.
The therapeutic principle behind hyperbaric oxygen therapy lies in its ability to drastically increase partial pressure of oxygen in the tissues of the body. In other words, cells repair themselves more efficiently when exposed to a higher oxygen content via the blood. Although the hyperbaric chamber itself is the same in most cases, it is used in different ways. That said, there are two ways that this treatment can help when it comes to scuba diving:
- Decompression Chamber:
A hyperbaric chamber used by surface-supplied (typically commercial) divers to make their decompression stops.
- Recompression Chamber:
A hyperbaric chamber used to treat or prevent patients suffering from decompression sickness.
The purpose a decompression hyperbaric chamber is to allow surface-supplied gas divers to complete their decompression stops in a chamber rather than underwater. The diver surfaces and immediately enters the decompression chamber to complete the time they would have normally spent underwater decompressing. This reduces the risks for divers diving in cold waters or in risky underwater conditions. Not to forget, this method of decompressing is mostly used in the case of commercial diving, which involves divers working for hours underwater at depths far beyond traditional recreational diving. Because of which they also spends hours (sometimes as long as 18 hours) for the decompression process.
hyperbaric chamber used for those divers who already have or show symptoms of Decompression Sickness (also known as decompression illness or the bends) is known mostly as a recompression chamber.
We’ve seen that, as long as the diver remains at pressure, the nitrogen gas absorbed by breathing compressed air underwater, presents no problem. However, when the pressure around the diver decreases the nitrogen starts coming out of the tissues back into the blood stream. If the pressure is reduced too quickly, the nitrogen starts forming bubbles in the tissues and bloodstream rather than being exhaled, just like when you open a bottle or can of soda, it releases the pressure causing the carbon dioxide gas to lose its solubility and escape in the form of bubbles or fizz. As a recompression chamber is pressurized, it re-simulates the pressure conditions as if the diver were underwater. By putting the patient back under pressure, it’s like putting the cap back on a soda bottle, and stopping the fizz from escaping. The pressure causes the nitrogen bubbles to become soluble again, thereby stopping them from escaping from through the tissues and bloodstream. A (very) risky alternative to a recompression chamber is actually sending the diver back underwater and under pressure to stop the gas bubbles that are causing DCS symptoms. It is called In-water recompression and is only considered as a last resort if the diver is too far from a hyperbaric chamber, and it’s a question of life or death. It doesn’t treat DCS as well as an actual recompression chamber because, it lacks the oxygen supply.
In a hyperbaric chamber used for recompression, the patient is delivered high oxygen partial pressure according to the pressure of the chamber. So, Hyperbaric Oxygen Treatment (HBOT) serves the dual-purpose of the oxygen encouraging the cells repair themselves more efficiently, while at the same time eliminating the excess nitrogen from the blood. At the end we can say out loud that the HBO is the standard and definitive treatment for divers with DCI and having a Recompression Chamber installed into a Diving Center or diving boats should become a standard care procedure . Immediate chamber access can lead to the resolution of a devastating injuries that might otherwise leave a diver permanently disabled; it may allow a diver to continue to enjoy the underwater world rather than be medically restricted from further diving!