Circadian Variation in Post Void Residual in Nursing Home Residents With Moderate Impairment in Activities of Daily Living.

Background: Despite the conflicting evidence about postvoid residual (PVR) and its variation in time and corresponding voided volume (VV), studies with urinary diaries and systematic measurements of PVR after each void have never been conducted in nursing home (NH) residents.

Objective: To describe the circadian rhythm of PVR and residual fraction (RF, the net quantity of PVR) and to identify the time window with the highest PVR and RF.

Design, Setting, And Participants: A multicentre prospective study conducted between 2014 and 2015 in 5 Belgian NHs. A convenience sample of cognitively intact residents completed a 24-hour frequency volume chart with PVR.

Results: Participants (n = 73) had a median age of 84 years (interquartile range 82-89) and moderate impairment of activities of daily living; 69% were women. In residents with nocturia, mean PVR was higher during the night [45 mL (26-80)] than during the day [36 mL (18-61)]. In residents without nocturia no difference was detected. In spite of the variation between diurnal and nocturnal VV and PVR in residents with nocturia, all residents emptied their bladder as effectively during daytime as during nighttime [mean RF = 20% (12-32)]. Maximum PVR and RF in residents with nocturia (n = 57) showed a circadian variation. The highest PVR and RF were found during the day. The PVR and RF of the first morning void were an indicator of the maximum nocturnal PVR and RF.

Conclusions: PVR and VV should be measured in NH residents during the waking hours (first morning void excepted) to detect the clinically relevant maximum PVR and RF.