title: Fluid responsiveness in spontaneously breathing patients: a review of indexes used in intensive care.
abstract: OBJECTIVE
  In spontaneously breathing patients, indexes predicting hemodynamic response to volume expansion are very much needed. The present review discusses the clinical utility and accuracy of indexes tested as bedside indicators of preload reserve and fluid responsiveness in hypotensive, spontaneously breathing patients.
  
  
  METHODS
  We conducted a literature search of the MEDLINE database and the trial register of the Cochrane Group.
  
  
  METHODS
  Identification of reports investigating, prospectively, indexes of fluid responsiveness in spontaneously breathing critically ill patients. All the studies defined the response to fluid therapy after measuring cardiac output and stroke volume using the thermodilution technique. We did not score the methodological quality of the included studies before the data analysis.
  
  
  METHODS
  A total of eight prospective clinical studies in critically ill patients were included. Only one publication evaluated cardiac output changes induced by fluid replacement in a selected population of spontaneously breathing critically ill patients.
  
  
  RESULTS
  Based on this review, we can only conclude that static indexes are valuable tools to confirm that the fluid volume infused reaches the cardiac chambers, and therefore these indexes inform about changes in cardiac preload. However, respiratory variation in right atrial pressure, which represents a dynamic measurement, seems to identify hypotension related to a decrease in preload and to distinguish between responders and nonresponders to a fluid challenge.
  
  
  CONCLUSIONS
  Further studies should address the question of the role of static indexes in predicting cardiac output improvement following fluid infusion in spontaneously breathing patients.
authors.affiliation: Geneva University Hospital, Geneva, Switzerland.
authors.forename: Alice
authors.initials: A
authors.lastname: Coudray
authors.forename: Jacques-André
authors.initials: JA
authors.lastname: Romand
authors.forename: Miriam
authors.initials: M
authors.lastname: Treggiari
authors.forename: Karim
authors.initials: K
authors.lastname: Bendjelid
mesh_terms: D001811:Blood Volume Determination / Q000379:methods*; D005440:Fluid Therapy / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D010953:Plasma Volume / Q000502:physiology*; D012119:Respiration; D014882:Water-Electrolyte Balance / Q000502:physiology*