Chamber pressures...

[twatto]

In general, what are the decompression pressures use in deco chambers?

Is there an exact science behind the pressures used, and the time spent at each pressure level?

 

[miked]

Hi Twatto,

I'm not a Dr.....etc....
But based on my experienxce, the pressures used depend upon the treatment "tables" used, which depend upon the severity of the diver's condition.

For example, IIRC, a "USN table 6" would take you to (the pressure equivalent of) 60' , for 2.5 hrs, then to 30' for 2 more, then to the surface in .5 hours.
Some "tables" are deeper and longer, some less so.

Is there an exact science? Science yes, but it is theory (according to one chamber director)-and the results of a particular treatment cannot always be predicted.
Frequently, the condition of the diver after a treatment will be the major determining factor in determining the next course of treatment.

I imagine that you'll soon get responses from some of the more medically-skilled board members, to fill in the gaps of what I have said.

take care,
Mike

 

[rmediver2002]

In general, what are the decompression pressures use in deco chambers?

Is there an exact science behind the pressures used, and the time spent at each pressure level?

Most chambers used for treatment or surface decompression (non-saturation / deep water systems) are rated to a depth of 190 FSW. These chambers normally have pressure relief valves that are set to operate at 100 PSI.

Most of the newer single lock treatment chambers are rated to 60 FSW.

Standard treatment depths used are:

190 FSW TT-6A

60 FSW US Navy treatment table 5, 6, (portions of treatment table 6A and 7 are also conducted at this depth

45 FSW US Navy treatment table 9

40 FSW Surface decompression tables

30 FSW later portion of 5 and 6

The tables are not an exact science as the nature of the injuries, the diver being treated, and the divers profile are so varied. It is more a matter of time tested results.

 

[Dr Deco]

Hello twatto :

Treatment Pressures

Tables have been developed over the last hundred years and modified considerable. The biggest change in the last forty years has been the introduction of oxygen treatment tables; these have greatly reduced the number of recurrences of DCS following the initial treatment.

Empirical

These treatment plans are basically empirical in nature as far as time and pressure are concerned. They do, however, all bear a common hallmark in that they attempt to minimize the reintroduction of inert gas into the tissues insofar as possible.

Treatment would best be accomplished by the use of very high pressure oxygen to redissolve the bas bubbles. This is not possible because of the toxic nature of oxygen. In fact, drug toxicity is often the limiting factor in the dosage of many medications. Toxicity is minimized by the addition of “air pauses/breaks.”

Dr Deco :doctor: