title: Extracorporeal membrane oxygenation using a centrifugal pump and a servo regulator to prevent negative inlet pressure.
abstract: BACKGROUND
  We studied whether negative inlet pressure created by a centrifugal pump during extracorporeal membrane oxygenation damages blood.
  
  
  METHODS
  Fresh, whole human blood and primer were circulated through a test circuit, applying an inlet pressure of 0, -50, or -100 mm Hg. Thereafter, hemolysis and kidney function were compared between 6 patients treated before and 14 patients treated after inclusion in our setup of extracorporeal membrane oxygenation with a servo inlet pressure regulator.
  
  
  RESULTS
  In vitro, negative inlet pressure caused substantial hemolysis, leukocyte and platelet destruction, and complement activation. Maximal plasma free hemoglobin concentrations were 199 mg/100 mL before use of the servo inlet pressure regulator and 40 mg/100 mL afterward (p = 0.06), and serum creatinine peaked at 330 and 115 mumol/L, respectively (p = 0.03). The minimal 24-hour diuresis normalized for weight was 4.8 mL/kg before use of the servo inlet pressure regulator and 45.6 mL/kg afterward (p = 0.03). Three of 5 evaluable patients before use of the servo inlet pressure regulator and 1 of 14 patients after inclusion in this setup experienced anuria (p = 0.04).
  
  
  CONCLUSIONS
  There were strong indications that reduction of negative pump inlet pressure with the servo regulator prevented hemolysis and kidney damage.
authors.affiliation: Surgical Department, National Hospital, University of Oslo, Norway.
authors.forename: T H
authors.initials: TH
authors.lastname: Pedersen
authors.forename: V
authors.initials: V
authors.lastname: Videm
authors.forename: J L
authors.initials: JL
authors.lastname: Svennevig
authors.forename: H
authors.initials: H
authors.lastname: Karlsen
authors.forename: R W
authors.initials: RW
authors.lastname: Ostbakk
authors.forename: O
authors.initials: O
authors.lastname: Jensen
authors.forename: T E
authors.initials: TE
authors.lastname: Mollnes
mesh_terms: D003167:Complement Activation; D003404:Creatinine / Q000097:blood; D015199:Extracorporeal Membrane Oxygenation / Q000295:instrumentation*; D005260:Female; D006400:Hematocrit; D006461:Hemolysis; D006801:Humans; D066298:In Vitro Techniques; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000503:physiopathology; D008297:Male; D011312:Pressure
chemical_list: D003404:Creatinine