title: Hidden Obligatory Fluid Intake in Critical Care Patients.
abstract: BACKGROUND
  In addition to the fluid intake in the form of intravenous maintenance or boluses in intensive care unit (ICU) patients, there are sources of fluids that may remain unrecognized but contribute significantly to the overall fluid balance. We hypothesized that fluids not ordered as boluses or maintenance infusions-"hidden obligatory fluids"-may contribute more than a liter to the fluid intake of a patient during any random 24 hours of critical care admission.
  
  
  METHODS
  Patients admitted to the Harlem Hospital ICU for at least 24 hours were included in this study (N = 98). Medical records and nursing charts were reviewed to determine the sources and volumes of various fluids for the study patients.
  
  
  RESULTS
  The mean hidden obligatory volume for an ICU patient was calculated to be 978 mL (standard deviation [SD]: 904, median: 645) and 1571 mL (SD: 1023, median: 1505), with enteral feeds compared to the discretionary volume of 2821 mL (SD: 2367, median: 2595); this obligatory fluid volume was affected by a patient's need for pressor support and renal replacement therapy.
  
  
  CONCLUSIONS
  Hidden obligatory fluids constitute a major source of the fluid intake among patients in a critical care unit. Up to 1.5 L should be taken into account during daily decision making to effectively regulate their volumes.
authors.affiliation: 1 Department of Surgery, Harlem Hospital Center, New York, NY, USA.
authors.forename: Muhammad Umair
authors.initials: MU
authors.lastname: Bashir
authors.affiliation: 1 Department of Surgery, Harlem Hospital Center, New York, NY, USA.
authors.forename: Anan
authors.initials: A
authors.lastname: Tawil
authors.affiliation: 1 Department of Surgery, Harlem Hospital Center, New York, NY, USA.
authors.forename: Vishnu R
authors.initials: VR
authors.lastname: Mani
authors.affiliation: 2 Pharmacy, Harlem Hospital Center, New York, NY, USA.
authors.forename: Umer
authors.initials: U
authors.lastname: Farooq
authors.affiliation: 3 Department of Surgery and Critical Care Medicine, Harlem Hospital Center, New York, NY, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: A DeVita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D003422:Critical Care / Q000379:methods; D016638:Critical Illness / Q000628:therapy*; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D019983:Guideline Adherence; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D011446:Prospective Studies; D014481:United States; D014882:Water-Electrolyte Balance; D055815:Young Adult
keywords: critical care; critical illness; dialysis; fluid therapy; hemodynamic monitoring; intensive care unit; monitoring; sedation; shock; volume status