title: Prediction of responsiveness to an intravenous fluid challenge in patients after cardiac surgery with cardiopulmonary bypass: a comparison between arterial pulse pressure variation and digital plethysmographic variability index.
abstract: OBJECTIVE
  Arterial pulse pressure variation (PPV) and digital plethysmographic variability index (PVI) have been proposed to predict fluid responsiveness during anesthesia and in critically ill patients. The present study aimed to compare the clinical utility of PPV and PVI in predicting fluid responsiveness after elective cardiac surgery.
  
  
  METHODS
  A prospective observational study.
  
  
  METHODS
  A university hospital.
  
  
  METHODS
  Eighty-seven adult patients.
  
  
  METHODS
  Admission to the intensive care unit after cardiac surgery. Investigation before and after fluid challenge.
  
  
  RESULTS
  The discrimination of both PPV and PVI in predicting fluid responsiveness was compared by using areas under the receiver operating characteristics curves (ROCAUC). Sensibility analyses were conducted after exclusion of patients with a low perfusion index, patients receiving norepinephrine, and patients with right ventricular dysfunction. Fifty-seven (71%) patients were responders and twenty-three (29%) were nonresponders. ROCAUC were 0.73 [95% CI: 0.63-0.83] versus 0.60 [95% CI: 0.48-0.71] for PPV and PVI in the whole cohort of patients, respectively (p = 0.020). The inconclusive class of responses included 47 (59%) and 62 (77%) patients, respectively (p = 0.010); whereas the discrimination of PVI remained low whatever the subgroup of patients, the discrimination of PPV markedly increased in patients without perfusion index ≤ 1.3 (ROCAUC = 0.83 [95% CI: 0.68-0.93]) and in patients without right ventricular dysfunction (ROCAUC = 0.85 [95% CI: 0.67-0.95]).
  
  
  CONCLUSIONS
  PVI is not discriminant and probably inaccurate to predict fluid responsiveness after elective cardiac surgery. PPV could be of potential interest after exclusion of patients with a low perfusion index and right ventricular dysfunction.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, CHU de Caen, Caen, France; Department of Cardiology, CHU de Caen, Caen, France. Electronic address: fischer-mo@chu-caen.fr.
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Fischer
authors.forename: Arnaud
authors.initials: A
authors.lastname: Pelissier
authors.forename: Dan
authors.initials: D
authors.lastname: Bohadana
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Gérard
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Hanouz
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Fellahi
mesh_terms: D000368:Aged; D062186:Arterial Pressure; D001794:Blood Pressure / Q000502:physiology*; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D005260:Female; D005385:Fingers / Q000098:blood supply; D005440:Fluid Therapy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010991:Plethysmography / Q000379:methods*; D011237:Predictive Value of Tests; D011674:Pulse; D012372:ROC Curve; D012039:Regional Blood Flow / Q000502:physiology; D012044:Regression Analysis; D015203:Reproducibility of Results
keywords: cardiac surgery; cardiopulmonary bypass; fluid responsiveness; intravenous fluid challenge; pulse pressure variation