title: Hydration amongst nurses and doctors on-call (the HANDS on prospective cohort study).
abstract: Dehydration of as little 2% of total body weight may impair physical and cognitive performance. The aim of this study was to investigate the prevalence of dehydration at the start and end of shifts in nurses and doctors on-call. The secondary aims were to assess the relation between hydration status and cognitive function.
  
  
  
  This prospective cohort study was conducted on nurses and doctors working on medical and surgical admissions wards at a university teaching hospital. Participants arrived on the ward approximately 20 min before their shift and were asked to provide a urine sample. Height and weight were then measured. A 10 mL blood sample was analysed for full blood count, serum urea and electrolytes, and blood glucose. Cognitive function was assessed using a series of computer-based tests including the Stroop Colour Naming Interference Test and Sternberg Memory Paradigm. Participants then worked normally but were asked to keep a fluid diary for the duration of their shift and fluid balance was estimated. Tests were repeated at the end of the shift. Dehydration was defined as urine osmolality >800 mOsmol/kg and oliguria was defined as urine output <0.5 ml/kg/hour.
  
  
  
  We recruited 92 nurses and doctors, of whom 88 completed the study, amounting to 130 shifts. 52% participated for one shift, and 48% for two shifts. Thirty-six percent of participants were dehydrated at the start of the shift and 45% were dehydrated at the end of their shift. Mean (SD) urinary osmolality was significantly greater at the end of the shift when compared with the start [720 (282) vs. 622 (297) mOsm/kg, P = 0.031). Moreover, 41% were oliguric at the end of the shift. Single number and five-letter Sternberg short-term memory tests were significantly impaired in dehydrated participants (P < 0.05).
  
  
  
  This study highlights that a significant proportion of nurses and doctors were dehydrated at the start and end of medical and surgical shifts. Dehydration was associated with some impairment of cognitive function.
authors.affiliation: Gastrointestinal Surgery, National Institute for Health Research Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals and University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: El-Sharkawy
authors.affiliation: Gastrointestinal Surgery, National Institute for Health Research Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals and University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.
authors.forename: Damian
authors.initials: D
authors.lastname: Bragg
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK.
authors.forename: Phillip
authors.initials: P
authors.lastname: Watson
authors.affiliation: Division of Public Health and Epidemiology, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.
authors.forename: Keith
authors.initials: K
authors.lastname: Neal
authors.affiliation: Department of Elderly Medicine, Nottingham University Hospitals, Queen's Medical Centre, Nottingham NG7 2UH, UK.
authors.forename: Opinder
authors.initials: O
authors.lastname: Sahota
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Maughan
authors.affiliation: Gastrointestinal Surgery, National Institute for Health Research Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals and University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK. Electronic address: Dileep.Lobo@nottingham.ac.uk.
authors.forename: Dileep N
authors.initials: DN
authors.lastname: Lobo
mesh_terms: D000328:Adult; D001835:Body Weight; D003071:Cognition; D003681:Dehydration / Q000453:epidemiology*; D004573:Electrolytes / Q000097:blood / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D009726:Nurses; D010820:Physicians; D015995:Prevalence; D011446:Prospective Studies; D000073577:Shift Work Schedule; D014882:Water-Electrolyte Balance; D055815:Young Adult
chemical_list: D004573:Electrolytes
keywords: Acute kidney injury; Cognitive function; Dehydration; Health care professionals; Hydration; Risk