The complaints and reasons include the
following:
Requirement to sleep on their backs due
mask to prevent leaking.
Pressure marks on face due to tightness of
Allergic reaction to materials in masks.
their sleep and their partner’s
sleep.
Mask leaks and the associated noise disturbing
when using the machine.
Feeling of claustrophobia and ‘drowning’
being attached to a machine through the
night.
The question now arises as to the
sequence of events in OSA.
What comes first – the apnoea or the
oxygen desaturation?
Conventional wisdom usually says that
the apnoea occurs due to obstruction of the
airway and that the desaturation is a consequence
of this.
If one considers the very foundation of
acid-base physiology, The Bohr Effect, and
the undisputed knowledge that oxygen saturation
is directly influenced by the pH of
arterial blood, this is back-to-front.
If the apnoea were to occur first – with
the concomitant cessation of breathing,
there would be an immediate spike in
PaCO
Taking into consideration that the vast
majority of people with sleep apnoea are
snorers and/or mouth breathers, it would
be safe to assume that they were suffering a
degree of alkalosis due to the excessive loss
of CO
The rapid rise in CO
apnoea, would therefore buffer the blood
towards its ideal pH of 7.35 and increase
oxygen saturation – rather than the other
way round.
There seems to be a lack of reporting, or
evidence – or in fact even measurement of
pre-apnoea SaO
to mis-diagnosis.
Some patients are misdiagnosed with
severe OSA, for 3 major reasons:
Firstly, the majority do not fit the profile
of the typical OSA patient.
Secondly, the conclusion reached at the
end of the sleep study was often less than
confident and CPAP was recommended as a
“catch-all” solution.
Finally, there was much emphasis placed
on oxygen saturation levels (SaO
fact that these improved dramatically during
CPAP usage.
Central Sleep Apnoea (CSA) was virtually
ruled out in the majority of the cases and,
at best, referred to as a standard component
of OSA.
If one considers the physiology and biochemistry,
associated with breathing, several
significant factors appear:
There are two major factors which trigger
the breathing response:
1. The pH of the blood, more specifically
the movement towards pH7.8 and alkalosis.
2. The hypoxic drive to breathe created
by reduction of oxygen to the brain.
Emotional and aesthetic objections to2.2 through the over-breathing.2, as a result of the2, which could in fact lead2) and the
to masks leaking when turning.
.
