100% 02 during your SI?

[Thalassamania]

Exactly.

Thats said, air breaks aren't common... They're not a part of the regimen.

...But you're right... They are available immediately at the first sign of tox.

My post above was in response to someone asking for "details.". Apparently that was several posts ago, and the conversation has gone further since. My apologies for bad netiquitte... I must have been reading an old post on this thread.

Forgive my response if it is untimely.

Wiki's piece on the subject is in line with my experience and is in line with what I was told by Rutkowski during his Chamber Operator course:

[h=3]Oxygen supply[/h] In today's larger multiplace chambers, both patients and medical staff inside the chamber breathe from either "oxygen hoods" – flexible, transparent soft plastic hoods with a seal around the neck similar to a space suit helmet – or tightly fitting oxygen masks, which supply pure oxygen and may be designed to directly exhaust the exhaled gas from the chamber. During treatment patients breathe 100% oxygen most of the time to maximise the effectiveness of their treatment, but have periodic "air breaks" during which they breathe room air (21% oxygen) to minimize the risk of oxygen toxicity. The exhaled gas must be removed from the chamber to prevent the build up of oxygen, which could present a fire risk. Attendants may also breathe oxygen to reduce their risk of decompression sickness. The pressure inside a hard chamber is increased by opening valves allowing high-pressure air to enter from storage cylinders, which are filled by an air compressor. A soft chamber may be pressurised directly from a compressor.


Smaller "monoplace" chambers can only accommodate the patient, and no medical staff can enter. The chamber may be pressurised with pure oxygen or compressed air. If pure oxygen is used, no oxygen breathing mask or helmet is needed, but the cost of using pure oxygen is much higher than that of using compressed air. If compressed air is used then an oxygen mask or hood is needed as in a multiplace, hard chamber. In monoplace chambers that are compressed with pure oxygen a mask is available to provide the patient with "air breaks," periods of breathing normal air (21% oxygen), in order to reduce the risk of hyperoxic seizures. In soft chambers, using compressed air and a mask supplying 96% oxygen, no air breaks are necessary as there is negligible risk of oxygen toxicity because of relatively low oxygen partial pressures and the short duration of treatment.

 

[Deep South Divers]

That's interesting... And more logical, frankly.

I haven't seen an air break in our monoplace chambers in a long time... Typical regimen is 2 ATAs on 100% (fed by a pair of liquid O2 containers next door and about 30 "k" style bottles) for a 1-hour treatment... No air breaks unless the patient begins to develop symptoms of CNS tox, which I haven't seen in many months.

I did not get the chance to watch the medical (healing) application of hyperbaric treatments in multiplace chambers at Duke... So I can't give you any first-hand details on the subject. My involvement with them was on the dive medicine side, not the wound care facility. However, I do know that the multiplace chambers there were using compressed air, not oxygen like these more modern monoplace chambers, and that 100% O2 was delivered to the patient by mask or hood, depending on the patient's needs. The mask was preferred because it tended to maintain better control of the oxygen, but not every patient was comfortable or able to use it.

I understood that with a technician or nurse riding the chamber with the patient, air breaks were common and easily done and well controlled. I don't see that with the monoplace chambers... Perhaps they simply don't because of the fact that the patient has to do it themselves to make it happen.

 

[Thalassamania]

I am far more familiar with multi-place and operating theater chambers, my only real experience with monoplace systems are the various portables designed for transport of a casualty. As far as the attendant is concerned, air breaks are not required because he or she is breathing air, not oxygen.

 

[Deep South Divers]

Yeah, man... There's been like 150 of them installed here in the Southeast over the past 24 months or so. They look like glass coffins. I think they're actually a thick acrylic. The tops are curved, and the end - at the head - opens and a gurney slides in and out for patient admittance.

The patient lies down on the gurney, the chamber op slides them in, and seals the small door, which might be 3' in diameter. The patient might feel claustrophobic except that the cylinder portion of the chamber is clear... So even inside, there is no feeling of claustrophobia.

On the door being swung shut is the air mask. It's very rarely used.

The operator's entire job can be summed up here: He pushes a button.

The chamber fills with 100% O2 from an outside source (evaporated liquid O2) and takes the patient to 2 ATAS, where it stays for an hour. The operator is there to monitor the computer, watch for issues with the patient, clean up after each patient and basically change the TV channel for the patient.

Cost: About $500, billed directly to the patient's insurance company.

Healing time is usually cut in half... Sometimes more. In the case of diabetic patients, they might not heal at all without treatment, especially if the wound is very far from the heart and lungs (eg the legs). Scarring on all wounds is dramatically reduced - and as such, there is a whole industry of these things popping up near cosmetic surgery establishments, too, as well as in "wound care" facilities which are usually associated closely with a hospital and abiding by the strict rules and regulations surrounding the medical community.

To the best of my knowlege, air breaks aren't standard practice in these monoplace chambers, although they were at Duke in the multiplaces. Again, I didn't spend much time on the medical side when I was there, though, so I can't speak for specifics.

These new chambers are cooooool... A fascinating way to make dive science work for the good of everybody.

 

[Deep South Divers]

Oh... FWIW... Just in case people were wondering about chambers being available for divers...

There's a lot of different approaches to the treatment of various barotraumas like DCS (or DCI, whichever you like to call it), but they usually involve 3 ATAs - 66fsw - or more of pressure in an AIR environment, probably with the administration of 100% O2. Typically, barotraumas are also closely supervised with medical professionals riding in the chamber with the patient for patient care. Patients might not always be conscious, too.

As such, these new monoplace chambers are inappropriate for the treatment of dive-related injuries, and do not count as possible facilities if you get "bent." Sorry, Charlie... You're gonna get LifeFlighted to the closest big city to ride the multiplace, and it's gonna cost ya a lot of money. If you live. Hope you have DAN insurance...

 

[Thalassamania]

There are older monoplace chambers (there was on on Calypso) that were capable of 165 FSW. Personally I do not like monoplace chambers for this purpose, but I guess they're better than nothing.

 

[SMPLtd]

Regarding what type of chambers are available for divers, most deck mounted chambers are between 50-60" diameter with either single lock or twin lock. SMP have been manufacturing hyperbaric chambers for around 30 years. Our standard diving chamber that we manufacture is a twin lock diver decompression chamber which is rated up to 10 bar (roughly 100 metres depth). A lot of hyperbaric oxygen therapy chambers are only rated up to 2 bar as treatments do not require this amount of pressure. As it is a twin lock chamber, this means that the entry lock can be pressurised independently of the main chamber lock. Therefore you can have 2 divers being treated simultaneously at different pressures. We made a triple lock chamber for Orkney last year which in comparison to our standard chamber is much larger. This was designed for emergency medical treatments requiring a rectangular door for ease of access.

Monoplace chambers are used for hyperbaric oxygen therapy treatments. I don't think the majority of monoplace chambers that are currently being sold in the US would not meet IMCA standards for offshore use.

Here are a couple of pictures to give you an idea of size: