Vascular Access and Infused Fluids for Pediatric CRRT 9th International pCRRT Conference on Pediatric Continuous Renal Replacement Therapy August 31-September 2, 2017 Vascular Access and Infused Fluids for Pediatric CRRT Jordan M Symons, MD Seattle Children’s Hospital University of Washington School of Medicine

Continuous Renal Replacement Therapy (CRRT) What does it take to make this work? Vascular access Infused fluids Rinse-O-Matic 3000

Vascular Access for Pediatric CRRT

Vascular Access for Pediatric CRRT: Starting Points Functional access is crucial for therapy Poor access = clotted circuits = lost Rx Achieving vascular access may be challenging Especially in smaller children “If you don’t have an access, you may as well go home”

Vascular Access for Pediatric CRRT: What Will Work? Usually HD catheter Temporary vs tunneled? Low resistance preferred Poiseuille’s law: R = 8hL/pr4 Therefore: Fat, short catheter would be best Caveats Longer catheter may reach larger vessel Fatter catheter is harder to place

Pediatric CRRT: Access Options Patient Size Catheter Size Neonates 7 Fr 3 – 6 Kg 6 – 12 Kg 8 Fr 12 – 20 Kg 9 Fr 20 – 30 Kg 10 Fr > 30 Kg 10 – 12 Fr Adapted from Cincinnati Children’s Hospital Center for Acute Care Nephrology Acute Dialysis/CRRT/Pheresis Access Guideline

Pediatric CRRT: Access Location Internal Jugular Very accessible Large caliber (SVC) Great flows Low recirculation rate Risk for Pneumothorax Cardiac monitoring may take precedence Femoral Usually accessible Smaller than SVC Flow hampered by: Abdominal pressure Patient movement Risk for retroperitoneal hemorrhage Higher recirculation rate Subclavian A suboptimal choice

Circuit Survival by Catheter Size Hackbarth R., et al. Int J Artif Organs. 2007 Dec;30(12):1116-21.

Circuit Survival by Catheter Location IJ Femoral SC 5Fr Demise! Hackbarth R., et al. Int J Artif Organs. 2007 Dec;30(12):1116-21.

Vascular Access Issues Long skinny catheters don’t flow well Umbilical lines are a poor choice “Dialysis-grade” catheters necessary Stiffer; won’t collapse Newer CRRT devices Options for neonates? Tunneled or temporary? Mobility Infection risk Performance Patient stability Speed/ease of access If starting with temp cath, consider when to change Important to communicate with those who place the access!

Infused Fluids for Pediatric CRRT

Purpose of CRRT solutions Provide safe and consistent metabolic control To be adaptive to the choice of therapy Convection Diffusion Combination

Diffusion

Convection

Clearance: Convection vs. Diffusion

Modality May Have an Impact on Choice of Solutions Diffusion requires the use of a dialysate Convection requires the use of replacement fluids R R D

What’s the Difference Between Dialysate and Replacement Fluid? Dialysate is a Device Replacement Fluid is a Drug

Options for CRRT Solutions Peritoneal dialysate: Pre-made IV solutions: Saline, Lactated Ringers Custom-made solutions: On-line generation: Commercially available CRRT solutions ANCIENT HISTORY MAYBE? RARELY DEVICE-DEPENDENT

Characteristics of the Ideal CRRT Solution Physiological Reliable Inexpensive Easy to prepare Simple to store Quick to the bedside Widely available Fully compatible Numerous solutions from multiple vendors available

Rate for Infused Fluid Higher rates increase clearance Lower rates may simplify electrolyte balance and limit losses Equations to help choose rate for fluid: 20-60 ml/kg/hr 2000 – 3000 ml/hr/1.73m2 May need higher rates to balance citrate delivery

Convection Favors Loss of Larger Molecules Consider your overall clinical goals when choosing solutions and modalities Small molecules and drugs Middle molecules and drugs Larger molecules and drugs Very large molecules and drugs

Issues with the Biochemical Profile of Infused CRRT Fluids Patient’s blood chemistry approaches that of infused fluids Errors in fluid content (mixing or inappropriate choice for situation) can lead to significant abnormalities x

Vascular Access and Infused Fluids for Pediatric CRRT Commercial solutions are a standard part of the modern CRRT prescription Allow improved clearance Need consideration to achieve balance Thoughtful hemocatheter selection and placement will permit effective therapy “It all starts with the access!”

Thanks! “Pull out, Betty! Pull out! . . . You’ve hit an artery!”