inner ear dci ?

[tyrell]

Hello all,
I heard about a phenomenon that when breaking from helium to air, decompression can accrue in the fluid inside the ear.

Is there anyone who can explain why, and why it happens only with heluim, and what is the difference in the fluid inside the ear, that something like that can happen.

To my opinion it’s nothing to do with the fluid itself but with pressure changes inside the ear that are reduced rapidly and much faster then the normal pressure change in the surrounding. I can imagine that this can happen because of a cold that blocks the channels inside the ear. When the channels are open there is a sudden drop in the pressure and then, decompression of of helium inside this fluid.

That’s what I think.
I will be happy to get a confirmation to this.( or the right answer in case im wrong)

Regards

Mark

 

[rmediver2002]

Inner ear DCS can occur with any gas mixture.

The fluid is very similar to cerebrospinal fluid.

To my opinion it’s nothing to do with the fluid itself but with pressure changes inside the ear that are reduced rapidly and much faster then the normal pressure change in the surrounding. I can imagine that this can happen because of a cold that blocks the channels inside the ear. When the channels are open there is a sudden drop in the pressure and then, decompression of of helium inside this fluid.

This is kind of alluding to barotrauma, the ear is going to be changing pressure with ambient.

Jeff Lane

 

[Cave Diver]

I read an article somewhere (I think it was Immersed) that talked about getting ear infections from the use of higher concentrations of 02 (nitrox or deco gas).

I'll see if I can dig up the details.

 

[rmediver2002]

Not sure about the article your reffering to cavediver but could it be?


Middle ear oxygen absorption syndrome, this can occur with any higher O2 mixture but is most common and was first identified in military 100% O2 re-breather divers.

Basically during the dive through normal respiration and while clearing the ears the diver gets a high ppO2 space within the middle ear. After surfacing this O2 will be slowly absorbed and metabolized within that space and periodically the diver will have to valsalva or clear the ears again. Often the divers go to bed for the evening and unless they set an alarm to wake them to clear during the night the O2 is absorbed and a barotrauma occurs.

The diver usually awake with a feeling of fullness in the ear and on examination fluid is normally present.

 

[Cave Diver]

rmediver2002 once bubbled...
Not sure about the article your reffering to cavediver but could it be?


Middle ear oxygen absorption syndrome, this can occur with any higher O2 mixture but is most common and was first identified in military 100% O2 re-breather divers.

Basically during the dive through normal respiration and while clearing the ears the diver gets a high ppO2 space within the middle ear. After surfacing this O2 will be slowly absorbed and metabolized within that space and periodically the diver will have to valsalva or clear the ears again. Often the divers go to bed for the evening and unless they set an alarm to wake them to clear during the night the O2 is absorbed and a barotrauma occurs.

The diver usually awake with a feeling of fullness in the ear and on examination fluid is normally present.

Bingo, you nailed it. It was presented in the Winter 2002 volume of Immersed Magazine.