title: Cumulative changes in weight but not fluid volume balances reflect fluid accumulation in ICU patients.
abstract: BACKGROUND
  The cumulative fluid balance of critically ill patients seems to be an outcome-relevant variable. However, there are no validated data for their reliability calculated for longer (> 5 days) periods of time.
  
  
  METHODS
  All ICU patients ≥ 18 years, with an ICU stay ≥ 5 days and a body weight ≤ 195 kg were evaluated from 1 January 2013 to 31 December 2013. Daily standardized weighing was performed using bed-integrated scales simultaneously with the daily 24-h fluid balance. Simultaneously, a fluid balance without and with insensible perspiration (10 ml/kg/day) was calculated for each 24 h. Primary endpoint: difference between cumulative fluid balance and body weight changes at the day of transfer to the normal ward or the day of death in the ICU, respectively, in each patient. All data are presented as medians with interquartile ranges (IQR) with 25 and 75 percentiles (IQR/25/75) unless otherwise noted.
  
  
  RESULTS
  One hundred and six critically ill patients were evaluated; 82 survivors and 24 nonsurvivors. Cumulative 24-h fluid balances rose continuously while body weight decreased over time. Correction of cumulative fluid balances for insensible perspiration (10 ml/kg/day) also did not match with body weight changes. Only survivors had a significant loss in body weight -1.8 (27.5/-6.1/1.0) kg.
  
  
  CONCLUSIONS
  Assuming that changes in body weight reflect changes in whole body water content cumulative daily fluid volume balances without or with correction for insensible water loss are not useful for estimating cumulative fluid balance of ICU patients. Survivors but not nonsurvivors had a significant loss of weight over time.
authors.affiliation: Department of Anaesthesia and Perioperative Medicine, Asklepios Klinik Langen, Langen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Köster
authors.affiliation: Department of Anaesthesia and Perioperative Medicine, Asklepios Klinik Langen, Langen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Dennhardt
authors.affiliation: Department of Anaesthesia and Perioperative Medicine, Asklepios Klinik Langen, Langen, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Jüttner
authors.affiliation: Department of Anaesthesia and Perioperative Medicine, Asklepios Klinik Langen, Langen, Germany.
authors.forename: H-B
authors.initials: HB
authors.lastname: Hopf
mesh_terms: D000368:Aged; D001835:Body Weight; D016638:Critical Illness; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D014882:Water-Electrolyte Balance