hyperbaric chamber and oxygen

[Seadogrun]

I am reading a book that discusses diving accidents. It seems to be a common theme in the book that the course of action after a DCS is to be placed in the hyperbaric chamber "taken" to a depth(ie 60') to decompress and given oxygen to breathe.

My question is:

Since the chamber simulates the pressure at depth(60' in this case), wouldn't the O2 become toxic at those pressures?

Thanks

 

[Norwegian Cave Diver]

There have been some great discussions here in SB regarding this topic. Do a history search and you will have lots to read.

 

[Wibble]

They compress the chamber using air which is not toxic at that pressure (=depth)

If you need to breathe high oxygen concentrations then they’ll put a plastic hood over your head and put oxygen/whatever in that.

 

[rjack321]

I am reading a book that discusses diving accidents. It seems to be a common theme in the book that the course of action after a DCS is to be placed in the hyperbaric chamber "taken" to a depth(ie 60') to decompress and given oxygen to breathe.

My question is:

Since the chamber simulates the pressure at depth(60' in this case), wouldn't the O2 become toxic at those pressures?

Thanks

More or less yes. But almost every drug you're given for any illness is toxic to some degree too, we call those "side effects". Effecting treatment while minimizing toxicity is why medicine via Dr Google isn't ideal

 

[Imla]

In this case, where you are put in chamber because of bubbles, the treatment is compression (of the bubbles) and then a slow ascent to surface with (eventual) oxygen on a mask.

Ox tox is normally not dangerous (albeit a bit nasty experience) in a chamber. A normal elective treatment protocol for non healing wounds is 30min 100% x3 sets with 5min airbreaks at 14m (IE, a pO2 of 2,4....)

 

[broncobowsher]

Oxygen toxicity is bad underwater as you spit out your reg and drown. One of the reasons commercial divers do helmet dives. Chamber ride doesn't really offer the chance to drown as you are not underwater.

There is also some discussion about dry vs. wet decompression. Although the pressures are the same, there are some differences that are not really understood. Short answer, dry is better than wet. Can't explain.

The result, you can safely ride the chamber at much higher levels of O2 than you can while diving.

 

[eelpout]

A comment given by a medical professional in Hyperbaric Medicine to me when asked the OP's question. "Exercise also increases the risk of CNS O2 toxicity, likely related to increased cerebral blood flow and metabolic rate". Patients in the chamber are either sitting down on a comfortable chair or laying down on Cart during HBOT (Hyperbaric Oxygen Therapy) compared to a diver who is swimming and exerting energy when you are diving. We also give patients air breaks, where the patient's mask/hood it taken off breathing a 100% for 5-10 minutes. This is done to minimize chances of getting CNS O2 Toxicity.

 

[Seadogrun]

Thank you all for helping me understand

 

[Akimbo]

Since the chamber simulates the pressure at depth(60' in this case), wouldn't the O2 become toxic at those pressures?

These threads explain it in detail:

Oxygen Toxicity Limits & Symptoms

Decompression & Treatment Simplified