title: Evaluation of stroke volume variations obtained with the pressure recording analytic method.
abstract: OBJECTIVE
  To investigate whether stroke volume variations obtained with the pressure recording analytic method can predict fluid responsiveness in mechanically ventilated patients with circulatory failure.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Surgical intensive care unit of a university hospital.
  
  
  METHODS
  Thirty-five mechanically ventilated patients with circulatory failure for whom the decision to give fluid was taken by the physician were included. Exclusion criteria were: Arrhythmia, tidal volume <8 mL/kg, left ventricular ejection fraction<50%, right ventricular dysfunction, and heart rate/respiratory rate ratio <3.6.
  
  
  METHODS
  Fluid challenge with 500 mL of saline over 15 mins.
  
  
  RESULTS
  Stroke volume variations and cardiac output obtained with a pressure recording analytic method, pulse pressure variations, and cardiac output estimated by echocardiography were recorded before and after volume expansion. Patients were defined as responders if stroke volume obtained using echocardiography increased by ≥15% after volume expansion. Nineteen patients responded to the fluid challenge. Median [interquartile range, 25% to 75%] stroke volume variation values at baseline were not different in responders and nonresponders (10% [8-16] vs. 14% [12-16]), whereas pulse pressure variations were significantly higher in responders (17% [13-19] vs. 7% [5-10]; p < .0001). A 12.6% stroke volume variations threshold discriminated between responders and nonresponders with a sensitivity of 63% (95% confidence interval 38% to 84%) and a specificity of 69% (95% confidence interval 41% to 89%). A 10% pulse pressure variation threshold discriminated between responders and nonresponders with a sensitivity of 89% (95% confidence interval 67% to 99%) and a specificity of 88% (95% confidence interval 62% to 98%). The area under the receiver operating characteristic curves was different between pulse pressure variations (0.95; 95% confidence interval 0.82-0.99) and stroke volume variations (0.60; 95% confidence interval 0.43-0.76); p < .0001). Volume expansion-induced changes in cardiac output measured using echocardiography or pressure recording analytic method were not correlated (r = 0.14; p > .05) and the concordance rate of the direction of change in cardiac output was 60%.
  
  
  CONCLUSIONS
  Stroke volume variations obtained with a pressure recording analytic method cannot predict fluid responsiveness in intensive care unit patients under mechanical ventilation. Cardiac output measured by this device is not able to track changes in cardiac output induced by volume expansion.
authors.affiliation: Emergency Department, Centre Hospitalier Universitaire de Bordeaux, France. matthieu.biais@chu-bordeaux.fr
authors.forename: Matthieu
authors.initials: M
authors.lastname: Biais
authors.forename: Vincent
authors.initials: V
authors.lastname: Cottenceau
authors.forename: Laurent
authors.initials: L
authors.lastname: Stecken
authors.forename: Maylis
authors.initials: M
authors.lastname: Jean
authors.forename: Laetitia
authors.initials: L
authors.lastname: Ottolenghi
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Roullet
authors.forename: Alice
authors.initials: A
authors.lastname: Quinart
authors.forename: François
authors.initials: F
authors.lastname: Sztark
mesh_terms: D002302:Cardiac Output / Q000502:physiology; D004452:Echocardiography / Q000379:methods; D005260:Female; D005440:Fluid Therapy / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011446:Prospective Studies; D012121:Respiration, Artificial; D013318:Stroke Volume / Q000502:physiology*; D013990:Tidal Volume / Q000502:physiology