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Accumulated 02 following a large number of repetitive Nitrox dives over 3 days.

Discussion in 'Advanced Scuba' started by Astran, Sep 30, 2019.

  1. Madacub

    Madacub Contributor

    # of Dives: 1,000 - 2,499
    Location:
    216
    29

    How about "ALL manifestation of oxygen toxicity, CNS/pulmonary/ocular are time and/or oxygen partial pressure dependent."?
     
  2. uncfnp

    uncfnp Solo Diver ScubaBoard Supporter

    # of Dives: 500 - 999
    Location: North Carolina
    6,635
    5,419
    Obviously all I know is what I read. Everything I have read links at least some degree of time exposure along with partial pressure. It obviously takes some time for the process to develop in both instances. But yes, the time/pressure variable for CNS toxicity is unique to each occurrence but it is still present. It’s why some of us feel comfortable briefly exceeding MOD when needed.

    Have I missed something?
     
  3. Madacub

    Madacub Contributor

    # of Dives: 1,000 - 2,499
    Location:
    216
    29
    MOD for nitrox is something I have never exceeded. (Deco, I'll sometimes deliberately go into depending on the situation) A PPO2 of 1.4 has a fair bit of buffer built in, maybe even 1.6 has a small bit. Maybe that's why you feel comfortable (?). I would not feel comfortable at all.

    Convulsions based on CNS toxicity can come on without warning, even at a MOD you have safely been to earlier. That's why I have been perhaps belaboring the point trying to figure out if time exposure to PPO2 can bring about CNS toxicity, even at depths less than the given PPO2 MOD.
     
  4. Jay

    Jay Need to dive more!

    # of Dives: 100 - 199
    Location: Melbourne, OZ.
    994
    566
    That a good article. Thanks. One highlight for me was:

    Screen Shot 2019-10-09 at 1.47.50 pm.png

    which make it surprising to me that SW only looks at CNS.

    FYI a while ago I asked this: OxTox (CNS) on Nitrox - what if you briefly exceed MOD significantly.
     
  5. rjack321

    rjack321 ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Port Orchard, Washington State
    11,152
    5,891
    Well anyone doing a 10+hr dive knows where they are OTU-wise and doesnt really need SW to remind them of that.
     
    Lorenzoid likes this.

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