The role of sleep measurements in patients with respiratory muscle weakness is currently uncertain. Polysomnography may be useful in patients with daytime sleepiness and suspected nocturnal hypoventilation, perhaps especially if awake PaCO2 is borderline or only mildly elevated.

Marked REM-related desaturation is seen occasionally in patients with relatively normal daytime SaO2 (26). More typically, however, the severity of nocturnal desaturation is predictable from daytime measurements, with more marked desaturation in patients with lower daytime PaO2, higher PaCO2, and lower VC (23) (Figure 9).


1 hour

Figure 7. Section of sleep recording of SaO2 and transcutaneous Pco2 (TcCO2) in a patient with chronic myopathy, showing mild desaturation (SaO2 90%) in non-REM sleep and frequent periodic dips in SaO2 in REM sleep. The Pco2 shows progressive elevation during REM periods. Reprinted by permission from Reference 23.

Figure 6. Relation of daytime PaCO2 to VC in 37 patients with uncomplicated chronic myopathy (closed circles, regression line) and 16 with myopathy plus chronic lung disease (open circles). Reprinted by permission from Reference 19.

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Healthy Sleep

Healthy Sleep

A Guide to Natural Sleep Remedies. Many of us experience the occasional night of sleeplessness without any consequences. It is when the occasional night here and there becomes a pattern of several nights in arow that you are faced with a sleeping problem. Repeated loss of sleep affects all areas of your life The physical, the mental, and theemotional. Sleep deprivation can affect your overall daily performance and may even havean effecton your personality.

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