If you haven’t heard yet about Hyperbaric Chambers, I hope you soon will if you decide to start being involved with underwater adventure and exploration. Don’t get me wrong, I do not mean I wish you bad luck. Actually, learning about what Hyperbaric chambers are, how they work and know that some of them can actually be a hazard for injured divers is the best way to protect you, dive in peace and relaxed!

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The Hyperbaric Chambers

What is a Hyperbaric Chamber?

Generally speaking, a hyperbaric chamber is a pressure vessel in which the pressure can be increased above its surrounding pressure.
It is also possible to find some hypobaric chambers in which the pressure is decreased below the surrounding pressure. Such chambers can sometimes be found in hospitals to isolate epidemiologic patients from the rest of the people. But we will focus on the Hyperbaric Chambers only here, which are the ones every certified diver should know about and not be afraid of.

The Multi-place Chamber

To start, you already know that there are three main types of hyperbaric chambers available, each of them having different capabilities and limits. Since only one of them is really able to provide an injured diver with the best treatment management and needs, there is a very important choice to make at the moment you call for help in case there are more than one recompression facility in the area where you are diving.

Inside Multi-Place Chamber assessment

This chamber is called the Multi-place chamber. It allows space for trained personnel to accompany the injured diver during the whole treatment duration for assistance and safety at all times.

Moreover, should additional complications occur, this chamber allows for constant access to the occupants by a hyperbaric doctor at any time and depth during the treatment. This is especially important as in some cases, decompressing the chamber to surface pressure can harm the injured diver even further, much like while underwater, going to the surface is not always the best immediate option. These chambers are also equipped with water sprinklers to better control any start of chamber fire. To further minimise the risk of fire, a multi-place chamber will always be pressurised with normal air against pure oxygen in other types.
On the comfort side of things, the occupants are free to sit up or even stand up and make use of the toilet while under pressure if needed during the five or more hours of treatment. Depth wise, those chambers can be pressurised to depths way beyond 50 meters of sea water if needed for critical cases with the use of mixed gases. This capability is unique to the multi-place chambers and can sometime make the difference between life or death.

These are some of the reasons why this kind of chamber is the only one allowed in several European countries or at least the preferred vessel for the treatment of injured divers worldwide. For additional information on dive safety and probably the best and cheapest dive insurance, I would advise you to visit the website of DAN Europe now.

Beds in Multi-place Chamber

Should you ever find yourself with possible symptoms of decompression illness (DCI) after any dive, first of all, do not wait to get checked by a DMO (Dive Medical Officer). Note: The general practitioners are not able to perform a proper check for possible DCI since this is a special branch of medicine they are not trained in. If you are diving in Thailand, the best number you can call for advice or emergency is the Hyperbaric Services of Thailand (HST) hotline on +66 (0) 810819000 or the office number on +66 76 209 347 (Phuket International Hospital
44/1 Chalermprakiat Ror 9 Rd.
Muang Phuket).
This will get you through a private hyperbaric facility staffed by European dive medics who are also all diving instructors, thus understanding what diving is all about. There you will receive professional advice on dive safety and dive accident management. You can also organise a date and time with the chamber staff to visit the chamber and even do a dry dive in it if you are doing your IDC (instructor course) with some of the local course directors.
If still in doubt, please contact the DAN Hotline for your region of origine (DAN Europe: +39 06 4211 8685).

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But in any case remember, your best chance of full recovery is early diagnostic and treatment.

The second type of recompression chamber is the Mono-place Chamber.

The Mono-place Chamber

This type of chamber is normally hospital based and designed to treat non-diving related conditions such as gas gangrene, problematic healing wounds, extensive burns and other conditions.
The treatment protocols used for these conditions are normally performed at shallower depths and for shorter

periods than those performed on injured divers. Also, the state of a patient treated for such conditions is very unlikely to deteriorate, which is far from being the case of an injured diver. We are touching here the first incompatibility between the mono-place chamber and the treatment of injured divers who are in need of constant support and evaluation. The mono-place chambers do not allow any access to the patient who is left alone under pressure during the whole treatment (5 hours or more).

As you can see here, the patient has no room to even sit up and is therefore not able to urinate or defecate by themselves while under pressure. Since an initial treatment for DCI is typically 5 hours minimum, if an injured diver is treated in a mono-place chamber against the recommendations of DAN, he/she will need to be catheterised for the whole treatment. Another issue is that most divers suffering from DCI are also dehydrated to an important stage and sometimes need to receive IV fluids to ensure a better perfusion of the oxygen to the body. But again, this is not possible in most mono-place chambers.

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So whatever happens and especially whatever the dive shop you are diving with tells you, ask to be sent to the closest multi-place chamber facility.

Transportable Chambers can also be used.

A Mono-place Transportable Chamber with soft shell

These chambers made out of various materials are obviously not designed to be used for long treatments of course and especially not for the treatment of injured divers. However, they can be of some assistance for injured divers in some specific cases.
Since anyone who has been diving should not go to altitudes above 300 meters (1000 Ft) for 12 to 24 hours after the dive to minimise the risk of DCI symptoms onset. However, in some cases we might face a problem when we have an injured diver and there is no evacuation possible to the nearest recompression chamber while staying below 300 meters. The reason why a diver should not go to altitude soon after diving is that it will even further decompress him/her, a decompression that was not accounted for in the dive plan and therefore is susceptible to trigger DCI.

A steel Multi-place Transportable Chamber

This is where the transportable chamber could come handy for diving injuries. Even if the transportable chambers can only be pressurised to shallow depths (0 to 5 meters of sea water) it is more than enough to solve our problem of altitude. Once a diver is pressurised inside the transportable chamber placed in a helicopter or a truck, he can be transported to any altitude without any problems since the pressure inside the chamber will remain the same, regardless of what is the pressure on the outside. So in this case, this chamber is definitely not used to treat anything but rather to avoid further deterioration of the injured diver and eliminate the low altitude requirement.
This is a device that could find its use on liveaboards doing trips in very remote locations where first aid can be very far away. However, due to the cost of this equipment, it is very seldom used and most popular diving destinations have other evacuation systems that do not necessitate the use of a transportable chamber.