title: Accuracy of stroke volume variation compared with pleth variability index to predict fluid responsiveness in mechanically ventilated patients undergoing major surgery.
abstract: OBJECTIVE
  Accurate assessment of a patient's volume status is an important goal for an anaesthetist. However, most variables assessing fluid responsiveness are either invasive or technically challenging. This study was designed to compare the accuracy of arterial pressure-based stroke volume variation (SVV) and variations in the pulse oximeter plethysmographic waveform amplitude as evaluated with the noninvasive calculated pleth variability index (PVI) with central venous pressure to predict the response of stroke volume index (SVI) to volume replacement in patients undergoing major surgery.
  
  
  METHODS
  We studied 20 patients scheduled for elective major abdominal surgery. After induction of anaesthesia, all haemodynamic variables were recorded immediately before (T1) and subsequent to volume replacement (T2) by infusion of 6% hydroxy-ethyl starch (HES) 130/0.4 (7 ml kg) at a rate of 1 ml kg min.
  
  
  RESULTS
  The volume-induced increase in SVI was at least 15% in 15 patients (responders) and less than 15% in five patients (nonresponders). Baseline SVV correlated significantly with changes in SVI (DeltaSVI; r = 0.80; P < 0.001) as did baseline PVI (r = 0.61; P < 0.004), whereas baseline values of central venous pressure showed no correlation to DeltaSVI. There was no significant difference between the area under the receiver operating characteristic curve for SVV (0.993) and PVI (0.973). The best threshold values to predict fluid responsiveness were more than 11% for SVV and more than 9.5% for PVI.
  
  
  CONCLUSIONS
  Although arterial pressure-derived SVV revealed the best correlation to volume-induced changes in SVI, the results of our study suggest that both variables, SVV and PVI, can serve as valid indicators of fluid responsiveness in mechanically ventilated patients undergoing major surgery.
authors.affiliation: Department of Anaesthesiology, University Hospital Regensburg, Regensburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Thomas
authors.initials: T
authors.lastname: Feibicke
authors.forename: Cornelius
authors.initials: C
authors.lastname: Keyl
authors.forename: Christopher
authors.initials: C
authors.lastname: Prasser
authors.forename: Stefan
authors.initials: S
authors.lastname: Moritz
authors.forename: Bernhard M
authors.initials: BM
authors.lastname: Graf
authors.forename: Christoph
authors.initials: C
authors.lastname: Wiesenack
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D017558:Elective Surgical Procedures / Q000379:methods; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010952:Plasma Substitutes / Q000008:administration & dosage; D010991:Plethysmography / Q000379:methods*; D012372:ROC Curve; D012121:Respiration, Artificial / Q000379:methods*; D015656:Respiratory Mechanics; D013318:Stroke Volume / Q000502:physiology*
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes