Neonatal and Infant CRRT Jordan M. Symons, MD University of Washington School of Medicine Children’s Hospital & Regional Medical Center Seattle, WA jordan.symons@seattlechildrens.org

Pediatric CRRT: Vicenza, 1984

This is a schematic of one of our old CRRT set-ups This is a schematic of one of our old CRRT set-ups. Here is a simple blood pump with an attached hemofilter. There are separate IV pumps for replacement fluids, for dialysate, and to generate the negative pressure to remove the ultrafiltrate. Because this system has dialysate and replacement fluids, it would most accurately be called CVVHDF. These glued-together systems were not terribly user friendly and could be inaccurate as well.

CRRT Machines: Current Generation Now, we have fancy new machines, dedicated to CRRT, able to perform numerous modalities accurately on a single platform. This one over here on the right, the Baxter BM-25, happens to be the machine we use here at Children’s. These new machines, and the other new technologies and techniques that have become available in only the last few years, have made CRRT a tremendously effective tool in the care of critically ill patients. I would add that despite all of this advancing technology, what really makes CRRT work for our patients is the incredible care and commitment of our nursing staff. Without our remarkable dialysis and ICU nurses, all of this would be useless.

Vascular Access for Pediatric CRRT Smaller patients require smaller catheters Difficulty achieving access Difficulty maintaining access Limited access sites

Choices for Vascular Access Catheter Type Manufacturers Potential Pts. Single-lumen 5Fr Cook Small Neonates Double-lumen 7Fr Medcomp 3 – 6 Kg Triple-lumen 7Fr Double-lumen 8Fr Kendall Arrow 6 – 30 Kg

Access Sites for CRRT Femoral veins Jugular veins Subclavian veins Umbilical vessels ECMO circuit

Prescribing CRRT for Small Kids Modality Blood flow rate Hemofilter Solution(s) Ultrafiltration rate Anticoagulation Special considerations

CRRT Modality for Small Kids Am J Kid Dis, 18:833-837, 2003

Hemofilters for Pediatric CRRT N Material Surface area (m2) Prime vol (ml) Renaflo® II HF-400 41 (48%) Polysulfone 0.3 28 Multiflow 60 20 (24%) AN-69 0.6 48 Fresenius F3 19 (22%) 0.4 30 Amicon® Minifilter® 5 (6%) 0.08 15 Am J Kid Dis, 18:833-837, 2003

Ultrafiltration Rate for Infant CRRT As tolerated by the patient Potentially limited by hemofilter, blood flow rates Small errors have a larger effect in a tiny patient

Anticoagulation for Infant CRRT Heparin Citrate Nothing ? Other things ?

Other Special Considerations for CRRT in Infants Large extracorporeal volume compared to small patient Blood prime (1:1 PRBC:Albumin 5%) at initiation frequently required Risk of thermic loss often requires heating system

Potential Complications of Infant CRRT Volume related problems Biochemical and nutritional problems Hemorrhage Infection Technical problems Logistical problems Bradykinin release syndrome

Logistical Issues for Infant CRRT Infrequently performed procedure in neonatal units Vascular access can be difficult to organize and obtain Neonatology staff may be unfamiliar with equipment, procedure, risks Written procedures may improve coordination and results of therapy

Bradykinin Release Syndrome Mucosal congestion, bronchospasm, hypotension at start of CRRT Resolves with discontinuation of CRRT Thought to be related to bradykinin release when patient’s blood contacts hemofilter Exquisitely pH sensitive

Technique Modifications to Prevent Bradykinin Release Syndrome Buffered system: add THAM, CaCl, NaBicarb to PRBCs Bypass system: prime circuit with saline, run PRBCs into patient on venous return line Recirculation system: recirculate blood prime against dialysate

Bypass System to Prevent Bradykinin Release Syndrome PRBC Waste Modified from Brophy, et al. AJKD, 2001.

Recirculation System to Prevent Bradykinin Release Syndrome Normalize pH Normalize K+ Recirculation Plan: Qb 200ml/min Qd ~40ml/min Time 7.5 min Waste Based on Pasko, et al. Ped Neph 18:1177-83, 2003

Outcomes for Pediatric CRRT Data are scant Most studies are single-center, retrospective No randomized controlled trials Small numbers limit power Extension from adult studies may not be appropriate

CRRT in Pediatric Patients <10Kg Multi-center, retrospective study 5 pediatric centers 85 patients Demographic data Technique description Outcome Am J Kid Dis, 18:833-837, 2003

Which Babies Require CRRT? Congenital heart disease Metabolic disorder Multiorgan dysfunction Sepsis syndrome Liver failure Malignancy Congenital nephrotic syndrome Congenital diaphragmatic hernia Congenital renal/urological disease Hemolytic uremic syndrome Heart failure Other 16.5% 15.3% 14.1% 10.6% 5.9% 4.7% 3.5% 2.4% 2.3% N=85 Am J Kid Dis, 18:833-837, 2003

Why do Babies Need CRRT? Combined volume overload and biochemical abnormalities of renal failure 54% Volume overload 18% Metabolic imbalance unrelated to renal failure (e.g., hyperammonemia) 14% Biochemical abnormalities of renal failure 9% Other (e.g., medication overdose) 4% Volume overload and hyperammonemia 1% N=85 Am J Kid Dis, 18:833-837, 2003

CRRT in Infants <10Kg: Outcome 38% Survival 41% Survival 25% Survival Patients <10kg Patients 3-10kg Patients <3kg Am J Kid Dis, 18:833-837, 2003

Survival by Diagnosis Totals: N=85; Survivors=32 Am J Kid Dis, 18:833-837, 2003 36% 71% 15% 42% 22% 50% 100% 60% Percentages instead of numbers Totals: N=85; Survivors=32

Survival by Modality Modality N Survivors CVVH 27 11 (41%) CVVHD 12 3 (25%) CVVHDF 4 (33%) CVVHD or CVVHDF 24 7 (29%) Am J Kid Dis, 18:833-837, 2003 p=NS

Retrospective Study of Infant CRRT: Summary Overall outcome acceptable 3 – 10kg: outcome similar to that for older patients Metabolic disorders: good outcome <3kg, selected diagnoses: poor outcome No clear advantage between modalities Am J Kid Dis, 18:833-837, 2003

Prospective Pediatric CRRT Registry (ppCRRT) Multi-center registry of pediatric CRRT Currently eleven US centers participating Collecting demographic, technical and outcome data on all pediatric patients receiving CRRT Sub-analysis of infants <10kg presented at ASN and PAS/ASPN

ppCRRT Data of Infants <10kg: Demographic Information 28 children <10 kg 14 boys, 14 girls Median age 40 days old Range 3 days to 2.9 years Median weight 4.1 kg Range 1.3 to 9.5 kg

ppCRRT Data of Infants <10kg: Indications for CRRT

ppCRRT Data of Infants <10kg: Vascular Access Location

ppCRRT Infant Survival Data

Infant CRRT: Continuing Questions How does CRRT compare to other modalities for small patients? What is optimal nutrition for infants on CRRT? What further equipment refinements are necessary? What is the long-term effect of CRRT?

Thanks!