title: Circadian Variation in Post Void Residual in Nursing Home Residents With Moderate Impairment in Activities of Daily Living.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: Department of Medical Sciences, Ghent University, Ghent, Belgium. Electronic address: veerle.decalf@uzgent.be.
authors.forename: Veerle
authors.initials: V
authors.lastname: Decalf
authors.affiliation: Department of Education, Health and Social work, University College Ghent, Ghent, Belgium.
authors.forename: Anja
authors.initials: A
authors.lastname: Huion
authors.affiliation: Department of Urology, Ghent University Hospital, Ghent, Belgium.
authors.forename: Marie-Astrid
authors.initials: MA
authors.lastname: Denys
authors.affiliation: Department of Medical Sciences, Ghent University, Ghent, Belgium.
authors.forename: Candy
authors.initials: C
authors.lastname: Kumps
authors.affiliation: Department of Geriatrics, Ghent University Hospital, Ghent, Belgium.
authors.forename: Mirko
authors.initials: M
authors.lastname: Petrovic
authors.affiliation: Department of Urology, Ghent University Hospital, Ghent, Belgium.
authors.forename: Karel
authors.initials: K
authors.lastname: Everaert
mesh_terms: D000203:Activities of Daily Living; D000369:Aged, 80 and over; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D009735:Nursing Homes; D011446:Prospective Studies; D016055:Urinary Retention
keywords: Frequency-volume charts; nocturia; nursing homes; postvoid residual; residual fraction