title: Fluid therapy and the hypovolemic microcirculation.
abstract: OBJECTIVE
  In shock states, optimizing intravascular volume is crucial to promote an adequate oxygen delivery to the tissues. Our current practice in fluid management pivots on the Frank-Starling law of the heart, and the effects of fluids are measured according to the induced changes on stroke volume. The purpose of this review is to evaluate the boundaries of current macrohemodynamic approach to fluid administration, and to introduce the microcirculatory integration as a fundamental part of tissue perfusion monitoring.
  
  
  RESULTS
  Macrocirculatory changes induced by volume expansion are not always coupled to proportional changes in microcirculatory perfusion. Loss of hemodynamic coherence limits the value of guiding fluid therapy according to macrohemodynamics, and highlights the importance of evaluating the ultimate target of volume administration, the microcirculation.
  
  
  CONCLUSIONS
  Current approach to intravascular volume optimization is made from a macrohemodynamic perspective. However, several situations wherein macrocirculatory and microcirculatory coherence is lost have been described. Future clinical trials should explore the usefulness of integrating the microcirculatory evaluation in fluid optimization.
authors.affiliation: aCritical Care Department, Hospital de Sabadell, Corporació Sanitària Parc Taulí, Universitat Autònoma de Barcelona, Sabadell, Spain bDepartment of Intensive Care, Erasmus MC University Hospital Rotterdam, Rotterdam, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Gruartmoner
authors.forename: J
authors.initials: J
authors.lastname: Mesquida
authors.forename: Can
authors.initials: C
authors.lastname: Ince
mesh_terms: D003422:Critical Care; D005440:Fluid Therapy / Q000009:adverse effects / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D020896:Hypovolemia / Q000503:physiopathology*; D008833:Microcirculation / Q000502:physiology*; D012769:Shock / Q000503:physiopathology* / Q000628:therapy