title: Automated pre-ejection period variation predicts fluid responsiveness in low tidal volume ventilated pigs.
abstract: BACKGROUND
  The respiratory variation in the pre-ejection period (Delta PEP) has been used to predict fluid responsiveness in mechanically ventilated patients. Recently, we automated this parameter and indexed it to tidal volume (PEPV) and showed that it was a reliable predictor for post-cardiac surgery, mainly paced, patients ventilated with low tidal volumes. The aims of the present animal study were to investigate PEPV's ability to predict fluid responsiveness under different fluid loading conditions and natural heart rates during low tidal volume ventilation (6 ml/kg) and to compare the performance of PEPV with other markers of fluid responsiveness.
  
  
  METHODS
  Eight prone, anesthetized piglets (23-27 kg) ventilated with tidal volumes of 6 ml/kg were subjected to a sequence of 25% hypovolemia, normovolemia, and 25% and 50% hypervolemia. PEPV, Delta PEP, pulse pressure variation (PPV), central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) were measured before each volume expansion.
  
  
  RESULTS
  Sensitivity was 89% and specificity was 93% for PEPV, 78% and 93% for Delta PEP, 89% and 100% for PPV, 78% and 93% for CVP, and 89% and 87% for PAOP.
  
  
  CONCLUSIONS
  PEPV predicts fluid responsiveness in low tidal volume ventilated piglets.
authors.affiliation: Aalborg Hospital, Aarhus University Hospital, Aalborg, Denmark. vistisen@ki.au.dk
authors.forename: S T
authors.initials: ST
authors.lastname: Vistisen
authors.forename: J
authors.initials: J
authors.lastname: Koefoed-Nielsen
authors.forename: A
authors.initials: A
authors.lastname: Larsson
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D001810:Blood Volume / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology*; D002405:Catheterization, Central Venous; D002496:Central Venous Pressure / Q000502:physiology; D004562:Electrocardiography; D005544:Forecasting; D006339:Heart Rate / Q000502:physiology; D020896:Hypovolemia / Q000503:physiopathology; D023421:Models, Animal; D010100:Oxygen / Q000097:blood; D011175:Positive-Pressure Respiration; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D012119:Respiration; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology; D013552:Swine; D013990:Tidal Volume / Q000502:physiology*
chemical_list: D010100:Oxygen