Neonatal and Infant CRRT

Jordan M. Symons, MD

University of Washington School of Medicine

Children’s Hospital & Regional Medical Center

Seattle, WAjordan.symons@seattlechildrens.org

Pediatric CRRT: Vicenza, 1984

CRRT Machines: Current Generation

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 CookSmall Neonates

Double-lumen 7FrCook

Medcomp3 – 6 Kg

Triple-lumen 7Fr Medcomp 3 – 6 Kg

Double-lumen 8FrKendall

Arrow6 – 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

2%

18%16%

21%43%

CVVH CVVHD CVVHDF SCUF >1 Modality

Am J Kid Dis, 18:833-837, 2003

Hemofilters for Pediatric CRRT

Filter N MaterialSurface

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%) Polysulfone 0.4 30

Amicon® Minifilter® 5 (6%) Polysulfone 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

D

Waste

Recirculation Plan:

Qb 200ml/min

Qd ~40ml/min

Time 7.5 min

Based on Pasko, et al. Ped Neph 18:1177-83, 2003

Normalize pH

Normalize K+

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%

16.5%

15.3%

14.1%

10.6%

5.9%

4.7%

3.5%

2.4%

2.3%

2.3%

5.9%

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

85

69

16

32 28

4

N

Survivors

Patients <10kg Patients 3-10kg Patients <3kg

38% Survival 41%

Survival

25% Survival

Am J Kid Dis, 18:833-837, 2003

Survival by Diagnosis14

14

13

12

9

5

4

3

2

2

1

1

5

5

10

2

5

2

0

2

0

1

1

1

0

3

Congen Ht Dz

Metabolic

Multiorg Dysfxn

Sepsis

Liver failure

Malignancy

Congen Neph Synd

Congen Diaph Hernia

HUS

Ht Failure

Obstr Urop

Renal Dyspl

Other

N

Survivors

Totals: N=85; Survivors=32

0

36%

71%

15%

42%

22%

0

50%

50%

50%

100%

0

60%

Am J Kid Dis, 18:833-837, 2003

Survival by Modality

Modality N Survivors

CVVH 27 11 (41%)

CVVHD 12 3 (25%)

CVVHDF 12 4 (33%)

CVVHD or CVVHDF 24 7 (29%)

p=NSAm J Kid Dis, 18:833-837, 2003

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

75%

25%Fluid and Electrolyte Imbalance

Metabolic Anomaly or Toxin

N=28

ppCRRT Data of Infants <10kg: Vascular Access Location

18%

67% 15%

Femoral Internal Jugular Subclavian

N=28

ppCRRT Infant Survival Data

1711

28

7 714

<5 kg 5 - 10 kg <10 kg

N

Survivors

41% Survival

64% Survival

50% Survival

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!