title: CVVHD treatment with CARPEDIEM: small solute clearance at different blood and dialysate flows with three different surface area filter configurations.
abstract: The CARdiorenal PEDIatric EMergency (CARPEDIEM) machine was originally designed to perform only continuous venovenous hemofiltration (CVVH) in neonatal and pediatric patients. In some cases, adequate convective clearance may not be reached because of a limited blood flow. In such conditions, the application of diffusive clearance [continuous venovenous hemodialysis (CVVHD)] would help optimize blood purification. In this study, the CARPEDIEM™ machine was modified to enable the circulation of dialysis through the filter allowing testing of the performance of CARPEDIEM™ machine in CVVHD.
  
  
  
  Three different polyethersulfone hemodialyzers (surface area = 0.1 m(2), 0.2 m(2), and 0.35 m(2), respectively) were tested in vitro with a scheduled combination of plasma flow rates (Qp = 10-20-30 ml/min) and dialysis fluid flow rate (Qd = 5-10-15 ml/min). Three sessions were performed in co-current and one in counter-current configuration (as control) for each filter size. Clearance was measured from the blood and dialysate sides and results with mass balance error greater than 5 % were discarded.
  
  
  
  Urea and creatinine clearances for each plasma/dialysate combination are reported: clearance increase progressively for every filter proportionally to plasma flow rates. Similarly, clearances increase progressively with dialysate flow rates at a given plasma flow. The clearance curve tends to present a steep increase for small increases in plasma flow in the range below 10 ml/min, while the curve tends to plateau for values averaging 30 ml/min. As expected, the plateau is reached earlier with the smaller filter showing the effect of membrane surface-area limitation. At every plasma flow, the effect of dialysate flow increase is evident and well defined, showing that saturation of effluent was not achieved completely in any of the experimental conditions explored. No differences (p > 0.05 for all values) were obtained in experiments using whole blood instead of plasma or using co-current versus counter-current dialysate flow configuration.
  
  
  
  Although plasma flow and filter surface give an important contribution to the level of clearance urea and creatinine, it appears evident that dialysate flow plays an essential role in the blood purification process, justifying the use of CVVHD versus CVVH in case of high dialysis dose requirement and/or limited blood flow rate.
authors.affiliation: International Renal Research Institute of Vicenza (IRRIV), Vicenza, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Lorenzin
authors.affiliation: International Renal Research Institute of Vicenza (IRRIV), Vicenza, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Garzotto
authors.affiliation: Department of Immunology and Blood Transfusions, San Bortolo Hospital, Vicenza, Italy.
authors.forename: Alberta
authors.initials: A
authors.lastname: Alghisi
authors.affiliation: International Renal Research Institute of Vicenza (IRRIV), Vicenza, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Neri
authors.affiliation: International Renal Research Institute of Vicenza (IRRIV), Vicenza, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Galeano
authors.affiliation: Nephrology, Dialysis and Transplantation "G. Brotzu" Hospital, Cagliari, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Aresu
authors.affiliation: Nephrology, Dialysis and Transplantation "G. Brotzu" Hospital, Cagliari, Italy.
authors.forename: Antonello
authors.initials: A
authors.lastname: Pani
authors.affiliation: Nephrology, Dialysis and Transplant Unit, Department of Woman's and Child's Health, Hospital and University of Padova, Padova, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Vidal
authors.affiliation: Department of Cardiology and Cardiac Surgery, Pediatric Cardiac Intensive Care Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
authors.forename: Zaccaroa
authors.initials: Z
authors.lastname: Ricci
authors.affiliation: Nephrology, Dialysis and Transplant Unit, Department of Woman's and Child's Health, Hospital and University of Padova, Padova, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Murer
authors.affiliation: Center for Acute Care Nephrology, Cincinnati Children's Hospital, Cincinnati, OH, USA. stuart.goldstein@cchmc.org.
authors.forename: Stuart L
authors.initials: SL
authors.lastname: Goldstein
authors.affiliation: International Renal Research Institute of Vicenza (IRRIV), Vicenza, Italy.|Department of Immunology and Blood Transfusions, San Bortolo Hospital, Vicenza, Italy.|Nephrology, Dialysis and Transplantation "G. Brotzu" Hospital, Cagliari, Italy.|Nephrology, Dialysis and Transplant Unit, Department of Woman's and Child's Health, Hospital and University of Padova, Padova, Italy.|Department of Cardiology and Cardiac Surgery, Pediatric Cardiac Intensive Care Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.|Department of Nephrology, Dialysis and Transplantation, San Bortolo Hospital, Vicenza, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Ronco
mesh_terms: D058186:Acute Kidney Injury / Q000628:therapy; D002648:Child; D003404:Creatinine / Q000097:blood; D015314:Dialysis Solutions; D004867:Equipment Design; D006440:Hemofiltration / Q000295:instrumentation*; D006801:Humans; D011108:Polymers; D013450:Sulfones; D014462:Ultrafiltration; D014508:Urea / Q000097:blood
chemical_list: D015314:Dialysis Solutions; D011108:Polymers; D013450:Sulfones; C022840:polyether sulfone; D014508:Urea; D003404:Creatinine
keywords: AKI; CRRT; CVVHD; Neonate; Pediatric RRT