title: Volume kinetics of intravenous fluid therapy in the prehospital setting.
abstract: BACKGROUND
  To study the volume effect of isotonic and hypertonic crystalloid fluid during ambulance transports after mild trauma, a prospective case-control study was initiated, using the ambulance and helicopter transport system in Stockholm.
  
  
  METHODS
  The hemodilution resulting from intravenous infusion of 1.0 L of Ringer's acetate solution (n = 7) or 250 ml of 7.5% sodium chloride (n = 3) over 30 minutes (min) was measured every 10 min during 1 hour when fluid therapy was instituted at the scene of an accident, or on arrival at the hospital. The dilution was studied by volume kinetic analysis and compared to that of matched, healthy controls who received the same fluid in hospital.
  
  
  RESULTS
  The hemodilution at the end of the infusions averaged 7.7% in the trauma patients and 9.1% in the controls, but the dilution was better maintained after trauma. The kinetic analysis showed that the size of the body fluid space expanded by Ringer's solution was 4.6 L and 3.8 L for the trauma and the control patients, respectively, while hypertonic saline expanded a slightly larger space. For both fluids, trauma reduced the elimination rate constant by approximately 30%.
  
  
  CONCLUSIONS
  Mild trauma prolonged the intravascular persistence of isotonic and hypertonic crystalloid fluid as compared to a control group.
authors.affiliation: Department of Anesthesiology, Söder Hospital, Stockholm, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Svensén
authors.forename: F
authors.initials: F
authors.lastname: Sjöstrand
authors.forename: R G
authors.initials: RG
authors.lastname: Hahn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000401:Aircraft; D000552:Ambulances; D001810:Blood Volume / Q000187:drug effects*; D001825:Body Fluid Compartments / Q000187:drug effects; D016022:Case-Control Studies; D004638:Emergency Treatment / Q000379:methods*; D005260:Female; D005440:Fluid Therapy / Q000009:adverse effects / Q000379:methods*; D006438:Hemodilution; D006801:Humans; D007552:Isotonic Solutions / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics*; D013997:Time Factors; D014187:Transportation of Patients; D014947:Wounds and Injuries / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*
chemical_list: D007552:Isotonic Solutions; C028570:Ringer's acetate; D012462:Saline Solution, Hypertonic