title: Features of an alternative hemodialysis method using a hemoconcentrator during cardiopulmonary bypass surgeries.
abstract: OBJECTIVE
  This study clarified the features of a hemoconcentrator-based, alternative hemodialysis (ALTHD) method that improves the speed of serum potassium (K(+)) concentration adjustments, compared with dilutional ultrafiltration (DUF), during cardiopulmonary bypasses.
  
  
  METHODS
  Standardized bovine blood was recirculated (300 ml/min) through an in vitro hemoconcentrator circuit; hematocrit, K(+) and glucose levels were measured at 5-20 min after DUF or ALTHD. We evaluated DUF at dialysis speeds of 50-250 ml/min and ALTHD at speeds of 50-1000 ml/min.
  
  
  RESULTS
  ALTHD rapidly corrected K(+) and glucose concentrations at speeds up to 800 ml/min. ALTHD took 8.9 min to reach a K(+) level of 4.5 mmol/L, faster than DUF (12.8 min). The ALTHD efficiency curves plateaued at 600 ml/min.
  
  
  CONCLUSIONS
  ALTHD allowed faster adjustment of electrolyte levels, with peak efficiency at 600 ml/min. ALTHD has possible clinical application if available for potential use during all cardiopulmonary bypass surgeries involving extracorporeal circulation.
authors.affiliation: Department of Medical Engineering, National Hospital Organization Kure Medical Center and Chugoku Cancer Center, Hiroshima, Japan Clinical Engineering Center, Ehime University Hospital, Ehime, Japan Division of Physiology, Hiroshima International University, Hiroshima, Japan tagayam@kure-nh.go.jp.
authors.forename: M
authors.initials: M
authors.lastname: Tagaya
authors.affiliation: Department of Internal Medicine, National Hospital Organization Kure Medical Center and Chugoku Cancer Center, Hiroshima, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Matsuda
authors.affiliation: Division of Physiology, Hiroshima International University, Hiroshima, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yakehiro
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Ehime, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Izutani
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D002315:Cardiopulmonary Bypass / Q000379:methods*; D002417:Cattle; D011188:Potassium / Q000097:blood*; D006435:Renal Dialysis / Q000379:methods*
chemical_list: D001786:Blood Glucose; D011188:Potassium
keywords: cardiopulmonary bypass; dialysis; electrolyte imbalance; extracorporeal circulation; hemoconcentrator