title: The impact of fluid therapy on microcirculation and tissue oxygenation in hypovolemic patients: a review.
abstract: OBJECTIVE
  An optimal volume replacement strategy aims to restore systemic hemodynamics with the ultimate goals of improving organ perfusion and microcirculation for sustaining adequate tissue oxygenation. This review presents the (patho)physiological basis of hypovolemia, microcirculation, and tissue oxygenation and presents a literature review on the effects of plasma substitutes on microperfusion and oxygenation in the clinical setting.
  
  
  METHODS
  Literature review of the effects of fluid therapy on microcirculation and tissue oxygenation using PubMed search including original papers in English from 1988 to 2009.
  
  
  RESULTS
  We identified a total of 14 articles dealing with the effects of different crystalloids and colloids on organ perfusion, microcirculation, and tissue oxygenation in patients. The results are divergent, but there is a general trend that colloids are superior to crystalloids in improving organ perfusion, microcirculation, and tissue oxygenation. Due to the limited number of studies and different study conditions, a meta-analysis on the effects of the volume replacement strategies on microcirculation is not possible.
  
  
  CONCLUSIONS
  Improving the microcirculation by volume replacement appears to be a promising issue when treating the critically ill. The growing insights from animal experiments have to be translated into the clinical setting to identify the optimal fluid regimen for correcting hypovolemia. New techniques for monitoring microcirculation at the bedside might provide such endpoints, although these have to be validated also in the clinical setting. Whether improved microperfusion and tissue oxygenation by fluid therapy will also improve patient outcomes will have to be proven by future studies.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Klinikum der Stadt Ludwigshafen, Bremserstr 79, 67063 Ludwigshafen, Germany. boldtj@gmx.net
authors.forename: Joachim
authors.initials: J
authors.lastname: Boldt
authors.forename: Can
authors.initials: C
authors.lastname: Ince
mesh_terms: D015687:Cell Hypoxia / Q000502:physiology; D005440:Fluid Therapy; D006801:Humans; D020896:Hypovolemia / Q000628:therapy*; D008833:Microcirculation / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption
chemical_list: D010100:Oxygen