Answer:
It's not a matter of how much air she uses but the definite risk of
having pulmonary barotrauma from 'burst' lung due to air-trapping. This
risk is quantified by the degree of abnormality found in your lungs.
This would be from the effects of Boyle's Law on ascending from a
compressed air dive. Sarcoidosis causes significant pleural reaction
and adhesions with the production of air-trapping. This air-trapping
does not allow for the proper release of expanding air upon ascent from
a dive - thus causing 'burst' lung. This can result in several things:
pneumothorax, pneumomediastinum, subcutaneous emphysema and gas
embolism with air bubbles getting into the arterial circulation and
causing a stroke-like picture.
It would be my feeling that your wife should cease her diving
activities until she gets some definitive advice from her
pulmonologist as to the possible dangers that she is facing. Spiral CT
scan of the lungs is sometimes helpful in dewlineating these problems.
Pulmonary Barotrauma from Sarcoidosis in a Chamber Dive
Here is a report of an accident that occurred in a recompression
chamber (dry dive) and reported in the journal of
Aviat Space Environ Med 1999;
70:594-7.
"An asymptomatic 46-yr-old male sustained an acute neurologic insult,
appearing during the decompression phase of a 50-m dry hyperbaric
chamber dive. The right hemisyndrome was most probably related to
diving, since symptoms responded rapidly to the early commenced
recompression therapy. Further diagnostics revealed a previously
unknown
pulmonary sarcoidosis
with bilateral pulmonary opacities and pleural adhesions that might
have predisposed to arterial gas embolism secondary to pulmonary
barotrauma. This case may illustrate a potential risk of decompression
illness even during dry chamber dives in patients suffering from
asymptomatic pleuro-parenchymal pulmonary disease.
The value of chest X-ray in the medical
assessment of fitness to dive is therefore emphasized. "
Abnormalities of pulmonary sarcoidosis are present in 90-95% of the
cases and remission (regression of symptoms and physical findings)
occurs in about two thirds of the cases of sarcoidosis with pulmonary
disease. Follow-up chest x-rays that show remission of the disease
probably can allow return to diving after full respiratory assessment
and one year of remission without recurrence of the disease. (in 'The
Sports Diving Medical', by John Parker, MD)