title: Predicting volume responsiveness by using the end-expiratory occlusion in mechanically ventilated intensive care unit patients.
abstract: OBJECTIVE
  During mechanical ventilation, inspiration cyclically decreases the left cardiac preload. Thus, an end-expiratory occlusion may prevent the cyclic impediment in left cardiac preload and may act like a fluid challenge. We tested whether this could serve as a functional test for fluid responsiveness in patients with circulatory failure.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Medical intensive care unit.
  
  
  METHODS
  Thirty-four mechanically ventilated patients with shock in whom volume expansion was planned.
  
  
  METHODS
  A 15-second end-expiratory occlusion followed by a 500 mL saline infusion.
  
  
  METHODS
  Arterial pressure and pulse contour-derived cardiac index (PiCCOplus) at baseline, during passive leg raising (PLR), during the 5-last seconds of the end-expiratory occlusion, and after volume expansion.
  
  
  RESULTS
  Volume expansion increased cardiac index by >15% (2.4 +/- 1.0 to 3.3 +/- 1.2 L/min/m, p < 0.05) in 23 patients ("responders"). Before volume expansion, the end-expiratory occlusion significantly increased arterial pulse pressure by 15% +/- 15% and cardiac index by 12% +/- 11% in responders whereas arterial pulse pressure and cardiac index did not change significantly in nonresponders. Fluid responsiveness was predicted by an increase in pulse pressure >or=5% during the end-expiratory occlusion with a sensitivity and a specificity of 87% and 100%, respectively, and by an increase in cardiac index >or=5% during the end-expiratory occlusion with a sensitivity and a specificity of 91% and 100%, respectively. The response of pulse pressure and cardiac index to the end-expiratory occlusion predicted fluid responsiveness with an accuracy that was similar to the response of cardiac index to PLR and that was significantly better than the response of pulse pressure to PLR (receiver operating characteristic curves area 0.957 [95% confidence interval [CI:] 0.825-0.994], 0.972 [95% CI: 0.849-0.995], 0.937 [95% CI: 0.797-0.990], and 0.675 [95% CI: 0.497-0.829], respectively).
  
  
  CONCLUSIONS
  The hemodynamic response to an end-expiratory occlusion can predict volume responsiveness in mechanically ventilated patients.
authors.affiliation: AP-HP, Hôpital de Bicêtre, Service de Réanimation Médicale, Le Kremlin-Bicêtre, France. xavier.monnet@bct.aphp.fr
authors.forename: Xavier
authors.initials: X
authors.lastname: Monnet
authors.forename: David
authors.initials: D
authors.lastname: Osman
authors.forename: Christophe
authors.initials: C
authors.lastname: Ridel
authors.forename: Bouchra
authors.initials: B
authors.lastname: Lamia
authors.forename: Christian
authors.initials: C
authors.lastname: Richard
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Teboul
mesh_terms: D005440:Fluid Therapy; D006439:Hemodynamics; D006801:Humans; D007362:Intensive Care Units; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D012121:Respiration, Artificial; D013997:Time Factors