Priory Lodge Education Limited 1997
First Published April 1997 Version 1.0

Respiratory Problems
During Sleep.

John R Stradling MD FRCP, Consultant Physician and Senior Clinical Lecturer.
Osler Chest Unit, Oxford, England.

It has become abundantly clear that disorders of breathing during sleep can have profound effects, only some of which are apparent during wakefulness. There is significant interaction between sleep and breathing in both directions: sleep changes the way we breath, and problems with breathing can profoundly fragment sleep.

Respiratory physiology of sleep

Sleep is not homogeneous and is conventionally divided into two states - non rapid eye movement (NREM) sleep and rapid eye movement sleep (REM) - which can be distinguished on behavioural and electrophysiological criteria. NREM sleep is further divided into stages 1 - 4; stages 3 and 4 represent the deeper levels of sleep (that are thought to be required to refresh the brain) and together are known as slow wave sleep (SWS). Periods of NREM and REM sleep alternate cyclically through the night at intervals of 90 - 120 minutes. The minimum amount of sleep that can be tolerated without adverse side effects varies between individuals, but the mean is approximately 6 - 7 hours.

There are two clinically important changes in ventilatory control and mechanics that normally accompany sleep:-

  Obstructive Sleep Apnoea
and variants
Symptoms in Obstructive Sleep Apnoea
Measuring the Consequences of OSA
Treatment of OSA
Central Sleep Apnoea
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