Hi Doctors,
I just read your posts and in regard to Dr Thomas's observation that "I doubt it was a problem with the gas, though, as I had used it on the first dive (for 48 minutes) without problem." I just wanted to point out that oxygen toxicity is extremely variable, not only on an individual to individual basis, but also on a day to day basis within the individual him/herself. In other words, every time I am in the water my tolerance to high pO2 exposure is different. This was shown conclusively in Kenneth Donald's 1992 book, "Oxygen and The Diver", p48 (Great Britain: The Spa Ltd.) His conclusion after experimenting with several divers being exposed to high pO2's for varying times was that, "it becomes clear that to judge even a single man's tolerance by one or even several dives is dangerous and unjustifable. If we examine the performances of three divers who survived for 100 minutes at 50 feet (on 100% O2), we find that the averages of all thier other performances at this depth are 22, 19, and 15 minutes respectively. One of the most striking cases is that of Gibson who convulsed after 12 minutes at 50 feet, 16 days later he completed 100 minutes without symptoms. Six days after this he again convulsed after 32 minutes. Such findings as this make it clear that to dive on oxygen to any toxic pressure involves risk that is impossible to assess." Now I understand that they were using much jigher than normal pO2's, but my point is that Dr. Thomas could have very easily, accomplished a prior dive to that depth and not had problems, then actually tox when exposed on a subsequent dive to the same or even lower pO2's.
I am also curious how hard you were working at the time of the loss of consciousness. I read that you were commencing practice
of "CBL", (forgive my ignorance, I don't know what "CBL" is), is this task very labor intensive? I am curious about possibility of CO2 buildup during this portion of your dive. As this is also believed to be a major contributor of ox-tox.
Just curious, these occurences of random loss of consciousness and/or seizures within pO2 limits arouse my curiosity, I really would not like that to happen to me or my mates while we are diving, so I try to understand what may be going on with the diver during these dives.
Thanks much for sharing with us!! It is highly appreciated! I am very gald to hear you are doing well!
