title: Hemodynamic effects of passive leg raising: an echocardiographic study in patients with shock.
abstract: OBJECTIVE
  To determine the effects of passive leg raising (PLR) on hemodynamics and on cardiac function according to the preload dependency defined by the superior vena cava collapsibility index (DeltaSVC).
  
  
  RESULTS
  Forty patients with shock, sedated and mechanically ventilated, were included. Transesophageal echocardiography was performed. At baseline (T1), two groups were defined according to DeltaSVC. Eighteen patients presenting a DeltaSVC > 36%, an indicator of preload dependency, formed group 1, whereas 22 patients (group 2) exhibited a DeltaSVC < 30% (not preload-dependent). Measurements were then performed during PLR (T2), back to baseline (T3), and after volume expansion (T4) in group 1 only. At T1, DeltaSVC was significantly higher in group 1 than in group 2, 50 +/- 9% and 7 +/- 6%, respectively. In group 1, we found a decrease in DeltaSVC at T2 (24 +/- 9%) and T4 (17 +/- 7%), associated with increased systolic, diastolic and arterial pulse pressures. Cardiac index also increased, from 1.92 +/- 0.74 (T1) to 2.35 +/- 0.92 (T2) and 2.85 +/- 1.2 l/min/m(2) (T4) and left ventricular end-diastolic volume from 51 +/- 41 to 61 +/- 51 and 73 +/- 51 ml/m(2). None of these variations was found in group 2. No change in heart rate was observed.
  
  
  CONCLUSIONS
  Hemodynamic changes related to PLR were only induced by increased cardiac preload.
authors: Centre Hospitalier Universitaire Ambroise Paré, 92104, Boulogne Cedex, France.
authors: Vincent
authors: V
authors: Caille
authors: Julien
authors: J
authors: Jabot
authors: Guillaume
authors: G
authors: Belliard
authors: Cyril
authors: C
authors: Charron
authors: François
authors: F
authors: Jardin
authors: Antoine
authors: A
authors: Vieillard-Baron
mesh_terms: D000368:Aged; D017548:Echocardiography, Transesophageal; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D012121:Respiration, Artificial; D012720:Severity of Illness Index; D012769:Shock / Q000145:classification / Q000503:physiopathology* / Q000628:therapy; D014683:Vena Cava, Superior