title: Superior vena caval collapsibility as a gauge of volume status in ventilated septic patients.
abstract: OBJECTIVE
  In mechanically ventilated patients inspiratory increase in pleural pressure during lung inflation may produce complete or partial collapse of the superior vena cava. Occurrence of this collapse suggests that at this time external pressure exerted by the thoracic cavity on the superior vena cava is greater than the venous pressure required to maintain the vessel fully open. We tested the hypothesis that measurement of superior vena caval collapsibility would reveal the need for volume expansion in a given septic patient.
  
  
  METHODS
  Prospective data collection for 66 successive patients in septic shock admitted in a medical intensive care unit and mechanically ventilated for an associated acute lung injury.
  
  
  RESULTS
  We simultaneously measured superior vena caval collapsibility by echocardiography and cardiac index by the Doppler technique at baseline and after a 10 ml/kg volume expansion by 6% hydroxyethyl starch in 30 min. The threshold superior vena caval collapsibility of 36%, calculated as (maximum diameter on expiration-minimum diameter on inspiration)/maximum diameter on expiration, allowed discrimination between responders (defined by an increase in cardiac index of at least 11% induced by volume expansion) and nonresponders, with a sensitivity of 90% and a specificity of 100%.
  
  
  CONCLUSIONS
  Superior vena cava measurement should be systematically performed during routine echocardiography in septic shock as it gives an accurate index of fluid responsiveness.
authors.affiliation: Medical Intensive Care Unit, University Hospital Ambroise Paré, Assistance Publique Hôpitaux de Paris, 9 avenue Charles de Gaulle, 92104 Boulogne Cedex, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Vieillard-Baron
authors.forename: Karim
authors.initials: K
authors.lastname: Chergui
authors.forename: Anne
authors.initials: A
authors.lastname: Rabiller
authors.forename: Olivier
authors.initials: O
authors.lastname: Peyrouset
authors.forename: Bernard
authors.initials: B
authors.lastname: Page
authors.forename: Alain
authors.initials: A
authors.lastname: Beauchet
authors.forename: François
authors.initials: F
authors.lastname: Jardin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018660:Blood Pressure Monitoring, Ambulatory; D002496:Central Venous Pressure; D018618:Echocardiography, Doppler, Color; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012121:Respiration, Artificial; D018805:Sepsis / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy; D012772:Shock, Septic / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D014683:Vena Cava, Superior / Q000473:pathology* / Q000503:physiopathology