Prevalence of nocturnal oxygen desaturation in patients admitted to a geriatric rehabilitation unit

Continuous oxygen measurement by digital oximetry is a well-established and widely used method. As reports in patients with cardiac disease have shown high prevalences of nocturnal oxygen desaturation, this study aimed to screen the patients admitted to a geriatric rehabilitation unit. Oxygen saturation was continously recorded during sleeptime in 103 unselected patients (52 women, 51 men) with a mean age of 77 y (65-90 y). The records were analysed according to standard rules concerning the frequency, duration and severity of periodic or phasic oxygen desaturations (ODES). Significant desaturations were found in 50/103 (48%) patients (43% women, 57% men) with a mean desaturation index (DESI) of 9.2 h-1. Periodic desaturations greater than 10 h-1 were found in 33% (35/103) patients with a mean DESI of 26/h in women and 20/h in men. Severe periods of desaturation (<80%) were found in 33% of women and in 41% of men. Patients with cardiac diseases showed the highest prevalence of total ODES (61%) and of periodic ODES (44%). Patients with lung diseases showed the highest prevalence of phasic ODES (43%). Patients admitted to the geriatric rehabilitation unit showed a considerably high prevalence of nocturnal oxygen desaturations. In contrast to earlier reports no significant influence of gender was found. The results presented here clearly support the urgent need for systematic sleep studies especially in elderly handicapped patients. Further investigations are needed to study clinical implications and the effects of therapeutic interventions.