Dear Marion,

Yesterday the mailman brought your medical records in a thick
envelope which I haven't yet opened. Meanwhile I have done more reading
about your pulmonary problem, and more thinking, and venture the
following hypothesis: One of the primary determinants of the relatively
low oxygen saturation is your physical habitus. At night, when
you are recumbent, the diaphragm protrudes into the thorax and
pushes against the lungs, limiting vital capacity. ("Orthopnea",
shortness of breath when recumbent, is a common, classical manifestation
of pulmonary insufficiency (as in cardiac failure.)) Your situation is
somehat unusual in that you are not aware of the low oxygen saturation.
I believe this to be the case because under some circumstances
one adapts to hypoxia, as for example, when one becomes accustomed
to breathing at high altitudes. My hypothesis can be tested by
ascertaining whether there is consistently difference in the oxygen
concentration between the upright position and reumbency.

I enjoyed very much "visiting with" you at the airport last Monday,
and I look forward to fetching you from there on August 11.
Meanwhile I apologize for the brevity of this letter. Various
chores are competing for my attention before patients arrive
in the early afternoon. Perhaps by now you've recovered from
your flight. I hope your visit is evolving according to your
expectations.

Jochen