Polysomnographic correlates of spontaneous nocturnal wetness episodes in incontinent geriatric patients.

Study Objective: To examine polysomnographic correlates of spontaneously occurring nocturnal wetness episodes (NWEs) in incontinent geriatric patients.

Design: Cross-sectional, descriptive study.

Setting And Participants: Subjects were 27 long-term nursing home residents known to be incontinent at night who were studied polysomnographically for 1 (n = 22) or 2 (n = 5) nights in their own rooms.

Interventions: None.

Measurements And Results: Traditional polysomnographic measurements were supplemented with a wetness monitor with a relay switch worn inside a diaper. A total of 106 NWEs were recorded, with approximately one third of all originating from sleep (non-rapid eye movement = 31; rapid eye movement = 4). Of the 106 total episodes, 11 (10.4%) began during a sleep-disordered breathing (SDB) event and 43 (40.6%) commenced within 60 seconds of termination of a breathing event. Urine volumes were calculated by weighing the diaper before and after each NWE. Volumes were significantly lower in NWEs originating during SDB events (127.1 mL vs 163.9 mL, t = 2.09, P < .05).

Conclusions: These results demonstrate that in a geriatric nursing-home population, many NWEs arise specifically from sleep and do not simply represent nocturnal voids made in response to difficulties in ambulation and arising from bed. A relatively large proportion of NWEs were related to SDB. Although SDB may be associated with nocturnal diuresis, the lower urine volumes associated with NWEs co-occurring with SDB raise the possibility that mechanical factors, such as downward displacement of the diaphragm exerting pressure on the detrusor, may contribute to urine leakage during sleep in such patients.