rebreather getting him dizzy?

[saturated]

Friends odd rebreather probs.

I have a friend taking a ccr class and he gets dizzy even on the prebreath. He is a very good OC diver with over 1000 dives including trimix. He has said that he notices no dizzyness on OC.

When he attempts to use a ccr he gets dizzy even on the pre-breath. He has tried 3 seperate units all with the same results.

He has since abandoned his quest and is sticking to OC with no noted problems.

Could there be a med explanation for this, co2 retention ect.

If there is a med explanation could this eventually affect his OC dives.

He has just completed a physical and nothing out of the ordinary was found.

thank you

 

[Doppler]

Really wierd and interesting post... looking forward to an explaination.

Doppler

 

[Saturation]

If dizziness occurs within minutes of using the rebreather, and diver is otherwise fine the most common problems are:

Hypoxia: lack of oxygen, check the mix
Hypercarbia: c02 build up, check the scrubber

Breathing resistance

All fall within basic critical issues during rebreather training.

 

[saturated]

all three units were woking fine, new scrubber packs ect. and were tested by 3 other rb divers immediately after the dizziness hitting him. Po2 was monitered very carfully when he pre-breathed with it set at .7. Non of us could experience the effects he had.

all mixes were checked and rechecked, 98 in the o2, air in the dilutent. Also should be noted the the tanks for all three rb's were not filled at same location.

 

[Saturation]

saturated once bubbled...
all three units were woking fine, new scrubber packs ect. and were tested by 3 other rb divers immediately after the dizziness hitting him. Po2 was monitered very carfully when he pre-breathed with it set at .7. Non of us could experience the effects he had.

all mixes were checked and rechecked, 98 in the o2, air in the dilutent. Also should be noted the the tanks for all three rb's were not filled at same location.

Hi Saturated:

Assuming the RB was set up correctly such as not to increase the work of breathing, and that the RB used by the problem diver was tested by other divers without issue, then one should look into lung problems in the afflicted diver.

A slight increase in the work of breathing may be without issue to normal lungs, but will be noticable to abnormal lungs. A simple pulmonary function test would be most revealing as its very sensitive to abnormalities, it can be done quickly in a Dr.'s office and further testing can be taken from there.