Does post-voiding residual volume get less as mobility improves in a rehabilitation ward for older adults?

Impaired bladder emptying is common in frail older adults. This study tests the hypothesis that more complete bladder emptying is associated with better mobility in a rehabilitation ward for older adults. Consecutive admissions to a rehabilitation ward for older adults were considered for inclusion in the study in the week after admission to the ward. Exclusion criteria were cognitive impairment such that consent could not be obtained, non-English speaking, or presence of an indwelling urinary catheter. A post-voiding residual (PVR) bladder volume and Rivermead Mobility Index (RMI) were completed for subjects who gave consent, on a weekly basis until discharge. The BladderScan BVI 3000, Diagnostic Ultrasound, instrument was used. Statistical analysis was by a general linear mixed model. In the study period, 114 people were admitted and 57 approached for consent. Twenty-four people gave consent. Fifty percent of participants had at least one PVR greater than 100 mL. One person was found to be in urinary retention, with a PVR of greater than 700 mL, and was excluded from further analysis. The PVR increased by 1.2 mL (95% CI-4.6 to 7) for each unit improvement in the RMI. This study suggests that PVR does not decline with improvement in mobility in older adults receiving inpatient rehabilitation.