Klarinet Archive - Posting 000805.txt from 1999/03

From: "Diane Karius, Ph.D." <dikarius@-----.edu>
Subj: RE: [kl] passing out (nearly)
Date: Sun, 14 Mar 1999 00:07:33 -0500

Two possibilities (both mundane & well documented) come to mind:

1) hyperventilation - when you hyperventilate, you decrease the blood
levels of CO2 (no major effect on O2, courtesy of the presence
of hemoglobin). The blood vessels in the brain are very sensitive to
the low levels of carbon dioxide (CO2) and *constrict* (get
narrower), thereby decreasing the amount of blood being delivered to
the brain. The neurons get less oxygen than they bargained for, and
begin to stop working (this is a neurons natural response to
decreased oxygen and happens very quickly). The world gets dark, you
get tingley lips, fingers and toes (not necessarily all, but some),
and you may zone out for a few seconds... (These sensations often
prolong a panic attack which has led to hyperventilation).

2) (and my scientific favorite - especially for the trumpet player
described): during well-supported tones, the pressure in the thorax
(chest) becomes positive. This positive pressure can be of
sufficient magnitude to impede the return of blood flow to the heart
(producing the typical red-faced trumpet player). Since less blood
is returning to the heart, the amount of blood pumped out by the
heart decreases, so the brain gets less blood, meaning the neurons
don't get the oxygen they need, they begin to shut down, the world
gets dark, they may get the tingles, and they may "pass out"
temporarily...

> Someone posted:
>
> >Another time, opening of one of Gershwins things with the low G trill
> >that glissandos up to high c. For some reason I started to worry, hit
> >the high c and started to pass out, only lost my vision for about 10
> >seconds, played through it from memory, sight came back with a slight
> >tingling sensation in the extremities.
> >
> >No fun.
>
> (Twilight Zone vamp in the background)
>
> This is really weird. Not that it happened, but that it also happened to
> ME--same piece, same sensation. I don't think it was from worry--I don't
> recall getting stage fright, it was the 4th performance--but perhaps
> something physiological about the glissando that causes a head rush?
>
> kjf
>
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>
Diane R. Karius, Ph.D.
Department of Physiology
University of Health Sciences
1750 Independence Ave.
Kansas City, MO 641o6-1453
email: dikarius@-----.EDU

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