title: Injection of agitated saline to detect recirculation with transthoracic echocardiography during venovenous extracorporeal oxygenation: A pilot study.
abstract: We assessed the security and efficiency of intravenously injected agitated saline in conjunction with transthoracic echocardiography to identify recirculation in patients supported with a venovenous extracorporeal membrane oxygenation (VV ECMO) device.
  
  
  
  We injected agitated saline 4 consecutive times separated by an interval of 5 minutes in 2 patients supported by VV ECMO. In both patients, the drainage cannula was placed in the left femoral vein, and the return cannula was placed in the right internal jugular vein. Echocardiography was performed during the injection and until the bubbles disappeared. The security of the method was assessed by evaluating the mechanical function of the ECMO and the efficiency of the oxygenator. The value of this method was assessed by visualizing the increase of inferior vena cava's echogenicity as well as by measuring the time required for this change to occur after the injection of agitated saline at different ECMO output levels.
  
  
  
  We did not observe any change in ECMO, oxygenation function, or the hemodynamic status of patients after the 4 injections of agitated saline. The echogenicity of the inferior vena cava increased more rapidly as the ECMO's output increased. The recirculation phenomenon was noted even with low levels of ECMO output (<2 L/min).
  
  
  
  Transthoracic echocardiography in conjunction with agitated saline administration may be a safe and easily applicable method to evaluate a recirculation phenomenon in patients supported with VV ECMO.
authors.affiliation: Department of Intensive Care Unit, Brugmann University Hospital, Université Libre de Bruxelles, Brussels, Belgium. Electronic address: charalmapos.pierrakos@chu-brugmann.be.
authors.forename: Charalampos
authors.initials: C
authors.lastname: Pierrakos
authors.affiliation: Department of Intensive Care Unit, Brugmann University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Vincent
authors.initials: V
authors.lastname: Collot
authors.affiliation: Department of Intensive Care Unit, Brugmann University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Hemlata
authors.initials: H
authors.lastname: Van Lieshout
authors.affiliation: Department of Intensive Care Unit, Brugmann University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Monique
authors.initials: M
authors.lastname: De Doncker
authors.affiliation: Department of Intensive Care Unit, Brugmann University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Delcourt
authors.affiliation: Department of Intensive Care Unit, Brugmann University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Gottignies
authors.affiliation: Department of Intensive Care Unit, Brugmann University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Jacques
authors.initials: J
authors.lastname: Devriendt
authors.affiliation: Department of Intensive Care Unit, Brugmann University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: David
authors.initials: D
authors.lastname: De Bels
mesh_terms: D000368:Aged; D004452:Echocardiography / Q000379:methods*; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007275:Injections, Intravenous; D007601:Jugular Veins; D008297:Male; D010106:Oxygenators; D010865:Pilot Projects; D011014:Pneumonia / Q000628:therapy*; D012128:Respiratory Distress Syndrome / Q000628:therapy*; D012772:Shock, Septic / Q000628:therapy*; D012965:Sodium Chloride; D014682:Vena Cava, Inferior
chemical_list: D012965:Sodium Chloride
keywords: ARDS, hypoxia; ECMO; Echocardiography; Recirculation