Mailing List Archive

Mailing List: techdiver

Message Display

Einar,

I bounced your question off Ernest Campbell M.D. at Diving Medicine
Online.  Question:  "A dive instructor with asthma asks about the risk
of 100% O2 for deco at 20-ft stop.  Also wonders about allowable
UPTD's (units of pulmonary toxic dose) given his stable asthma."

Dr. Campbell's answer:  "I'm not aware of any studies relating asthma
and O2 pulmonary toxicity.  A reduction in vital capacity would be the
main thing your dive instructor would notice over a period of repet
dives with 100% O2 deco at 20 feet.  The other factor might be
bronchospasm from the O2, noticed immediately.  Lambertsen's UPTD's
are calculated by formula using time, pressure and a constant of
0.5 as a threshold in bars, and asthma would have nothing to do with
changing or increasing the risk further.  His daily exposure limits
would not be any different with or without asthma."

Hope that helps a little.  Asthma is a relative contraindication to
diving and you know undoubtedly that you are walking a fine line.
It has been the subject of a great deal of debate over the years, and
was once considered an absolute contraindication to diving.  Because
there are several different types of asthma and because it can be well
controlled with meds, the standards have been relaxed somewhat in
recent years.  Take it easy and good luck.

MJB

__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
http://messenger.yahoo.com
--
Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.
Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.

Navigate by Author: [Previous] [Next] [Author Search Index]
Navigate by Subject: [Previous] [Next] [Subject Search Index]

[Send Reply] [Send Message with New Topic]

[Search Selection] [Mailing List Home] [Home]