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

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 SCUF and CAVH used by Paganini (MD) and Whitman (RN) at Cleveland Clinic

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)

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

History of Continuous Renal Replacement Therapy (CRRT) th International pCRRT meeting in Zurich, Switzerland th International pCRRT meeting in Orlando, FL th International pCRRT meeting in Rome, Italy

Bunchman Brophy Goldstein SymonsSomers The Founding Five

Indications for CRRT in the Critical Care Setting Fluid removal Solute removal

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

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

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.

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

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

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.

Solute Mass Transfer in CRRT Post-Dilution CVVHCVVHD Pre-Dilution CVVHCVVHDF QbQb QbQb QbQb QbQb Q ef f QdQd QdQd QrQr QrQr QrQr

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

Definition of Acronyms and Terms

SLEDDslow low efficient daily dialysis or sustained low- efficiency daily dialysis

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

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?

Dialysate A solution of variable composition designed to facilitate diffusion of solutes into the ultrafiltrate- dialysate compartment of the hemofilter or hemodialyzer.

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

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

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

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

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

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

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