title: Predilution versus postdilution during continuous venovenous hemofiltration: a comparison of circuit thrombogenesis.
abstract: During continuous venovenous hemofiltration, predilution can prolong circuit survival time, but the underlying mechanism has not been elucidated. The aim of the present study was to compare predilution with postdilution, with respect to circuit thrombogenesis. Eight critically ill patients were treated with both predilutional and postdilutional continuous venovenous hemofiltration in a crossover fashion. A filtration flow of 60 ml/min was used in both modes. We chose blood flows of 140 and 200 ml/min during predilution and postdilution, respectively, to keep the total flow through the hemofilter constant. Extracorporeal circuit pressures were measured hourly, and samples of blood and ultrafiltrate were collected at five different time points. Thrombin-antithrombin complexes and prothrombin fragments F1 + 2 were measured by ELISA, and platelet activation was assessed by flow cytometry. No signs of thrombin generation or platelet activation were found during either mode. During postdilution, baseline platelet count and maximal prefilter pressure had a linear relation, whereas both parameters were inversely related with circuit survival time. In summary, predilution and postdilution did not differ with respect to extracorporeal circuit thrombogenesis. During postdilution, baseline platelet count and maximal prefilter pressure were inversely related with circuit survival time.
authors.affiliation: Departments of Intensive Care, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Anne-Cornélie J M
authors.initials: AC
authors.lastname: de Pont
authors.forename: Catherine S C
authors.initials: CS
authors.lastname: Bouman
authors.forename: Kamran
authors.initials: K
authors.lastname: Bakhtiari
authors.forename: Marianne C L
authors.initials: MC
authors.lastname: Schaap
authors.forename: Rienk
authors.initials: R
authors.lastname: Nieuwland
authors.forename: Augueste
authors.initials: A
authors.lastname: Sturk
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Hutten
authors.forename: Evert
authors.initials: E
authors.lastname: de Jonge
authors.forename: Margreeth B
authors.initials: MB
authors.lastname: Vroom
authors.forename: Joost C M
authors.initials: JC
authors.lastname: Meijers
authors.forename: Harry R
authors.initials: HR
authors.lastname: Büller
mesh_terms: D018806:APACHE; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000187:drug effects; D001783:Blood Flow Velocity; D001792:Blood Platelets / Q000187:drug effects; D001794:Blood Pressure; D016638:Critical Illness / Q000628:therapy; D018592:Cross-Over Studies; D005260:Female; D006400:Hematocrit; D006440:Hemofiltration / Q000379:methods* / Q000592:standards*; D006454:Hemoglobins; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D017762:Nadroparin / Q000008:administration & dosage / Q000627:therapeutic use*; D010314:Partial Thromboplastin Time; D015539:Platelet Activation / Q000187:drug effects; D010976:Platelet Count; D011517:Prothrombin Time; D013917:Thrombin / Q000032:analysis; D013923:Thromboembolism / Q000188:drug therapy*; D014508:Urea / Q000097:blood
chemical_list: D000925:Anticoagulants; D006454:Hemoglobins; D017762:Nadroparin; D014508:Urea; D013917:Thrombin