Investigation of cyanotic/apneic episodes and sleep-related upper airway obstruction by long-term non-invasive bedside recordings.

Over a 4 year period, investigations were performed on 226 infants and children suffering cyanotic episodes and 160 suspected to be the victims of sleep-related upper airway obstruction. These investigations have been considerably aided by long-term tape recordings of multiple cardiorespiratory and neurophysiological variables from non-invasive sensors. In addition to identifying the underlying mechanisms responsible for cyanotic episodes, recordings have identified the presence or absence of airway obstruction, documented its severity by its effects on oxygenation and on sleep-state organization, and evaluated objectively the effects of treatment. The recording system, which is transportable, has been especially developed for use outside of the specialized sleep laboratory and was used on patients in hospital wards and at home.