title: Predicting Fluid Responsiveness by Passive Leg Raising: A Systematic Review and Meta-Analysis of 23 Clinical Trials.
abstract: OBJECTIVE
  Passive leg raising creates a reversible increase in venous return allowing for the prediction of fluid responsiveness. However, the amount of venous return may vary in various clinical settings potentially affecting the diagnostic performance of passive leg raising. Therefore we performed a systematic meta-analysis determining the diagnostic performance of passive leg raising in different clinical settings with exploration of patient characteristics, measurement techniques, and outcome variables.
  
  
  METHODS
  PubMed, EMBASE, the Cochrane Database of Systematic Reviews, and citation tracking of relevant articles.
  
  
  METHODS
  Clinical trials were selected when passive leg raising was performed in combination with a fluid challenge as gold standard to define fluid responders and non-responders.
  
  
  METHODS
  Trials were included if data were reported allowing the extraction of sensitivity, specificity, and area under the receiver operating characteristic curve.
  
  
  RESULTS
  Twenty-three studies with a total of 1,013 patients and 1,034 fluid challenges were included. The analysis demonstrated a pooled sensitivity of 86% (95% CI, 79-92), pooled specificity of 92% (95% CI, 88-96), and a summary area under the receiver operating characteristic curve of 0.95 (95% CI, 0.92-0.98). Mode of ventilation, type of fluid used, passive leg raising starting position, and measurement technique did not affect the diagnostic performance of passive leg raising. The use of changes in pulse pressure on passive leg raising showed a lower diagnostic performance when compared with passive leg raising-induced changes in flow variables, such as cardiac output or its direct derivatives (sensitivity of 58% [95% CI, 44-70] and specificity of 83% [95% CI, 68-92] vs sensitivity of 85% [95% CI, 78-90] and specificity of 92% [95% CI, 87-94], respectively; p < 0.001).
  
  
  CONCLUSIONS
  Passive leg raising retains a high diagnostic performance in various clinical settings and patient groups. The predictive value of a change in pulse pressure on passive leg raising is inferior to a passive leg raising-induced change in a flow variable.
authors.affiliation: 1Department of Intensive Care Medicine, Academic Medical Center, Amsterdam, the Netherlands. 2Department of Cardiology, Academic Medical Center, Amsterdam, the Netherlands. 3Department of Anesthesiology, Academic Medical Center, Amsterdam, the Netherlands. 4Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, Amsterdam, the Netherlands. 5Department of Intensive Care Medicine, Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Academic Medical Center, Amsterdam, the Netherlands. 6Department of Intensive Care Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands.
authors.forename: Thomas G V
authors.initials: TG
authors.lastname: Cherpanath
authors.forename: Alexander
authors.initials: A
authors.lastname: Hirsch
authors.forename: Bart F
authors.initials: BF
authors.lastname: Geerts
authors.forename: Wim K
authors.initials: WK
authors.lastname: Lagrand
authors.forename: Mariska M
authors.initials: MM
authors.lastname: Leeflang
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Schultz
authors.forename: A B Johan
authors.initials: AB
authors.lastname: Groeneveld
mesh_terms: D001794:Blood Pressure; D002302:Cardiac Output; D005440:Fluid Therapy / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007866:Leg; D015203:Reproducibility of Results