title: Crystalloid infusion rate during fluid resuscitation from acute haemorrhage.
abstract: BACKGROUND
  Information is lacking concerning optimal infusion rates of crystalloid during resuscitation from acute haemorrhage. In this study, a mathematical model was used to predict infusion volume of crystalloid needed to restore and maintain blood volume after acute haemorrhage.
  
  
  METHODS
  The scenario was a haemorrhage of 15 ml kg(-1) over 30 min in a 70 kg man. A bolus of crystalloid was administered at a rate of 40, 60, 80, 100, or 120 ml kg(-1) h(-1) until blood volume was restored. Fluid infusion rate needed to maintain blood volume for a further 1 h was computed.
  
  
  RESULTS
  Blood volume was restored earlier at high bolus infusion rates compared with low bolus infusion rates (6 min at 120 ml kg(-1) h(-1) vs 63 min at 40 ml kg(-1) h(-1)). Fluid infusion rates for blood volume maintenance approached 33 ml kg(-1) h(-1) irrespective of bolus infusion rates. The restoration fluid volume at 40 ml kg(-1) h(-1) was 2.9 litre, three times that at 80-120 ml kg(-1) h(-1). The maintenance fluid volume at 80-120 ml kg(-1) h(-1) was 2.9 litre, 0.6 litre more than that at 40 ml kg(-1) h(-1). During the blood volume maintenance, the interstitial volume increased to 3.8 litre above normal at 40 ml kg(-1) h(-1) and to 2.5 litre at 80-120 ml kg(-1) h(-1).
  
  
  CONCLUSIONS
  Bolus crystalloid infusion exceeding 80 ml kg(-1) h(-1) may not increase effectiveness of fluid resuscitation. Crystalloid resuscitation for more than 2 h may be detrimental in view of an excessive net fluid retention.
authors.affiliation: Department of Anaesthesiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan. ttatara@hyo-med.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Tatara
authors.forename: T
authors.initials: T
authors.lastname: Tsunetoh
authors.forename: C
authors.initials: C
authors.lastname: Tashiro
mesh_terms: D000208:Acute Disease; D016063:Blood Loss, Surgical; D001810:Blood Volume; D000077324:Crystalloid Solutions; D005440:Fluid Therapy / Q000379:methods*; D006470:Hemorrhage / Q000628:therapy*; D006801:Humans; D007262:Infusions, Intravenous; D007552:Isotonic Solutions / Q000008:administration & dosage* / Q000627:therapeutic use; D008297:Male; D008954:Models, Biological; D015532:Rehydration Solutions / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D000077324:Crystalloid Solutions; D007552:Isotonic Solutions; D015532:Rehydration Solutions