Night sleep of patients with chronic ventilatory failure and age matched controls: number and duration of the EEG episodes of intervening wakefulness and drowsiness.
Characteristics of the episodes of wakefulness and drowsiness (stage 0 + 1) intervening in a night of electrophysiologically monitored sleep were compared in a homogeneous group of 13 patients (mean age 57 years) with severe hypoxic chronic bronchitis and emphysema (blue and bloated variety) and 8 age matched control subjects. The total amounts of stage 0 + 1 accumulated over one night (preceded by one night of adaptation) were high in both groups (28% in the patients, 22% in the control subjects). A significant difference was found in the number of brief arousals (episodes of stage 0 + 1 lasting for less than 1 min), which averaged 10/h of sleep in the patients, and 6/h of sleep in the control subjects (p less than 0.05, two tailed). The numbers of longer episodes of stage 0 + 1 were not significantly different and varied independently from the numbers of brief arousals in the individuals. Only a small proportion (8 %) of brief arousals was linked to episodes of hypopnea or apnea in the bronchitic patients. Large numbers of brief arousals/h of non rapid eye movement sleep inthe bronchitic patients correlated significantly with small percentages of stage 3 + 4 sleep (p less than 0.05), and were associated with smell numbers of hypoxemic episodes occurring predominantly in rapid eye movement sleep. The findings indicate a more fractionated sleep in the patients with chronic hypoxic bronchitis, and suggest that the brief arousals represent a limiting factor rather than a result of the nocturnal hypoxemic episodes occurring in these patients.
D001143:Arousal / Q000502:physiology; D001921:Brain / Q000503:physiopathology*; D001991:Bronchitis / Q000150:complications / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000150:complications / Q000503:physiopathology*; D012890:Sleep / Q000502:physiology*; D012891:Sleep Apnea Syndromes / Q000503:physiopathology; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology; D014851:Wakefulness / Q000502:physiology