1. 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

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

3. Vascular Access for Pediatric CRRT

4. 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”

5. 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

6. 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

7. 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

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

9. Circuit Survival by Catheter LocationIJ
Femoral SC
5Fr Demise!
Hackbarth R., et al. Int J Artif Organs Dec;30(12):

10. 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!

11. Infused Fluids for Pediatric CRRT

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

13. Diffusion

14. Convection

15. Clearance: Convection vs. Diffusion

16. 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

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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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!”

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