PCRRT Tûr'mə-nŏl'ə-jē

1. PCRRT Tûr'mə-nŏl'ə-jē Helen Currier BSN, RN, CNN Assistant Director, Renal/Pheresis Texas Children’s Hospital Houston, Texas

2. History of Continuous Renal Replacement Therapy (CRRT) • 1960 Continuous arteriovenous approach first described for treatment of renal failure • 1974 Ultrafiltration isolated from hemodialysis circuit and the addition of a hemofilter • 1975 Hemofiltration technique proposed • 1979-82 SCUF and CAVH used by Paganini (MD) and Whitman (RN) at Cleveland Clinic

3. History of Continuous Renal Replacement Therapy (CRRT) • 1980s CRRT used in pediatrics • 1987 Pump-assisted CRRT introduced • 1990 CRRT considered state of the art therapy for treatment of acute renal failure • 1993 Standards of Clinical Practice for CRRT published by the American Nephrology Nurses’ Association (ANNA) and endorsed by the American Association of Critical Care Nurses (AACN)

4. History of Continuous Renal Replacement Therapy (CRRT) • 1998 SLEDD introduced as an alternative to CRRT • 2000 Continued development of integrated blood pump and fluid balance equipment for CRRT • 2002 2nd International pCRRT meeting in Orlando, FL • 2004 3rd International pCRRT meeting in Orlando, FL

5. History of Continuous Renal Replacement Therapy (CRRT) • 2006 4th International pCRRT meeting in Zurich, Switzerland • 2008 5th International pCRRT meeting in Orlando, FL • 2010 6th International pCRRT meeting in Rome, Italy

6. The Founding Five Bunchman Brophy Goldstein Symons Somers

7. Indications for CRRT in the Critical Care Setting • Fluid removal • Solute removal

8. Basic Concepts of CRRT: Concepts Related to Fluid Removal or Ultrafiltration • Blood flow • Arteriovenous • Venovenous • Hydrostatic pressure • Arteriovenous • Venovenous • Other factors • Hematocrit • Plasma proteins • Transmembrane pressure

9. Basic Concepts of CRRT: Concepts Related to Solute Removal or Clearance • Convection – solute drag; hemofiltration • Diffusion – concentration gradient; hemodiafiltration

10. Convection High pressure  to low pressure across a membrane Pressure gradient Solute dissolved in solvent = solvent drag Bulk-flow of solute across a semi-permeable membrane together with a solvent in a manner that is dependent on transmembrane pressure and membrane characteristics.

11. Basic Concepts of CRRT: Concepts Related to Solute Removal or Clearance • Convection – solute drag; hemofiltration • Diffusion – concentration gradient; hemodiafiltration

12. Diffusion Describes solute transport across a semi-permeable membrane generated by a concentration gradient.

13. Hemodiafiltration (HDF) A technique associated with high ultrafiltration rates and diffusion across a highly permeable membrane. Blood and dialysate are circulated as in hemodialysis, but in addition, ultrafiltration, in excess of the scheduled weight loss, is provided. Replacement fluid is used to achieve fluid balance. http://www.usa-gambro.com/upload/Site_us/Patient%Resources/IC/cvvhdf.gif

14. Post-Dilution CVVH CVVHD Qr Qb Qb Qeff Qeff Qd Qr Qr Qb Qb Qeff Qeff Qd Pre-Dilution CVVH CVVHDF Solute Mass Transfer in CRRT

15. Solute Molecular Weight and Clearance Solute (MW) Sieving Coefficient Diffusion Coefficient Urea (60) 1.01 ± 0.05 1.01 ± 0.07 Creatinine (113) 1.00 ± 0.09 1.01 ± 0.06 Uric Acid (168) 1.01 ± 0.04 0.97 ± 0.04* Vancomycin (1448) 0.84 ± 0.10 0.74 ± 0.04** *P<0.05 vs sieving coefficient**P<0.01 vs sieving coefficient

16. Definition of Acronyms and Terms • SCUF slow continuous ultrafiltration • CAVHcontinuous arteriovenous hemofiltration • CAVHD continuous arteriovenous hemodialysis • CVVH continuous venovenous hemofiltration • CVVHD continuous venovenous hemodialysis • CVVHDF continuous venovenous hemodiafiltration

17. Definition of Acronyms and Terms • SLEDD slow low efficient daily dialysis or sustained low- efficiency daily dialysis

18. Are those usually prescribed for a period of 12 hours or less. Extended Daily Dialysis (EDD) Slow Low Efficiency Dialysis (SLED) EDD+SLED=SLEDD Intermittent therapies

19. Continuous Renal Replacement Therapy • Advantages • Slower blood flows • Slower UF rates • Adjust UF rates with hourly patient intake • Increased cytokine (bad humors) removal? • Disadvantages • Prolonged anticoagulation • Increased cytokine (good humors) removal?

20. Dialysate A solution of variable composition designed to facilitate diffusion of solutes into the ultrafiltrate-dialysate compartment of the hemofilter or hemodialyzer. http://www.shodor.org/master/biomed/physio/dialysis/hemodialysis/sixa.htm#hollowfiber

21. Peritoneal Dialysis An intracorporeal therapy where solute and water are transported across the peritoneal membrane based on osmotic and concentration gradients.

22. Hemodialysis An extracorporeal, primarily diffusive therapy, where solute and water are transported across a semi-permeable membrane into dialysate.

23. High flux A dialysis membrane designed to provide high water permeability, thereby increasing solute clearance especially large solute such as beta-2 microglobulin.

24. Transmembrane Pressure The hydrostatic pressure gradient across the membrane. This is the driving force that causes ultrafiltration.

25. The Pediatric Ideal: CRRT Circuit • Minimum priming volume with low resistance • Exchangeable components • Biocompatible membrane

26. The Pediatric Ideal: CRRT Equipment • Separate and accurate pumps and scales for each component of CRRT • Range of blood flows with a minimum of 20ml/min • Thermoregulation • Maximum safety features

27. The Pediatric Ideal: CRRT Equipment • Comes with a expert nurse!