Acute Renal Replacement Therapy for the Infant

Jordan M. Symons, MDUniversity of Washington School of Medicine

Children’s Hospital & Regional Medical CenterSeattle, WA

jordan.symons@seattlechildrens.org

Objectives

• Indications and goals for acute renal replacement therapy

• Modalities for renal replacement therapy– Peritoneal dialysis– Intermittent hemodialysis– Continuous renal replacement therapy

(CRRT)

• Special issues related to the infant

Indications for Renal Replacement

• Volume overload

• Metabolic imbalance

• Toxins (endogenous or exogenous)

• Inability to provide needed daily fluids due to insufficient urinary excretion

Goals of Renal Replacement

• Restore fluid, electrolyte and metabolic balance

• Remove endogenous or exogenous toxins as rapidly as possible

• Permit needed therapy and nutrition

• Limit complications

Renal Replacement for the Infant: A Set of Special Challenges

• Small size of the patient

• Equipment designed for larger people

• Small blood volume will magnify effects of any errors

• Achieving access may be difficult

• Staff may have infrequent experience

Modalities for Renal Replacement

• Peritoneal dialysis

• Intermittent hemodialysis

• Continuous renal replacement therapy (CRRT)

Modalities for Renal Replacement

• Peritoneal dialysis

• Intermittent hemodialysis

• Continuous renal replacement therapy (CRRT)

PD: Considerations for Infants

ADVANTAGES• Experience in the

chronic setting• No vascular access• No extracorporeal

perfusion• Simplicity• ? Preferred modality

for cardiac patients?

DISADVANTAGES• Infectious risk• Leak• ? Respiratory

compromise?• Sodium sieving• Dead space in tubing

H2O

H2OH2O

H2O

H2O

H2O

H2O

H2O

H2O H2O

Sodium Sieving: A Problem of Short Dwell PD

Na+

Na+ Na+

Na+

H2O

Na+

Na+

Na+

Na+

Result: Hypernatremia

Dead Space: A Problem with Low Volume PD

Modalities for Renal Replacement

• Peritoneal dialysis

• Intermittent hemodialysis

• Continuous renal replacement therapy (CRRT)

IHD: Considerations for Infants

ADVANTAGES• Rapid particle and fluid

removal; most efficient modality

• Does not require anticoagulation 24h/d

DISADVANTAGES• Vascular access• Complicated• Large extracorporeal

volume• Adapted equipment• ? Poorly tolerated

Modalities for Renal Replacement

• Peritoneal dialysis

• Intermittent hemodialysis

• Continuous renal replacement therapy (CRRT)

Pediatric CRRT: Vicenza, 1984

CRRT for Infants: A Series of Challenges

• Small patient with small blood volume

• Equipment designed for bigger people

• No specific protocols

• Complications may be magnified

• No clear guidelines

• Limited outcome data

Potential Complications of Infant CRRT

• Volume related problems

• Biochemical and nutritional problems

• Hemorrhage, infection

• Thermic loss

• Technical problems

• Logistical problems

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

ppCRRT Data of Infants <10Kg: Demographic Information

Number of Subjects 84(51 boys (61%))(33 girls (39%))

Age Median 69 days(1 d - 2.9 y)

ICU Admit weight Median 4.4 kg(1.3 - 10 kg)

ppCRRT Data of Infants <10Kg: Primary Diagnoses

19%

10%

21%

15%35%

Sepsis GI/Hepatic Cardiac Inborn Error of MetabolismPulmonary

ppCRRT Data of Infants <10Kg: Indications for CRRT

Fluid Overload and Electrolyte Imbalance 84%

Other (Endogenous Toxin Removal) 16%

N=84

ppCRRT Data of Infants <10Kg: Clinical Data

Parameter Median Range

Days in ICU prior to CRRT 2 0 - 135

PRISM score — ICU admit 17.5 0 - 48

PRISM score — CRRT start 20 0 - 48

Inotrope number — CRRT start 1 0 - 4

Urine output — CRRT start(ml/kg/hr over prior 24hrs)

0.7 0 - 12

% Fluid overload from ICU admission to CRRT start

13.7 -28 - 220

ppCRRT Data of Infants <10Kg: Technical Characteristics of CRRT

Catheter Site Femoral 60%

Internal Jugular 28%

Subclavian 12%

Modality CVVHD 59%

CVVH 18%

CVVHDF 23%

Anticoagulation Citrate 55%

Heparin 45%

Prime Blood 87%

Saline 8%

Albumin 5%N=84

ppCRRT Data of Infants <10Kg: CRRT Treatment Data

N=84

Parameter Median Range

Blood Flow (ml/kg/min) 8 1.7-46

Fluid Flow (ml/kg/hour) 67 7-571

Average CRRT Clearance (ml/hr/1.73M2) 2582 135-19319

Aggregate CRRT Clearance (ml/hr/1.73M2) 3540 135-12713

CRRT duration (days) 5 0-83

ppCRRT Data of Infants <10Kg: Survival by Weight

0%

10%

20%

30%

40%

50%

60%

70%

<5 kg 5-10 kg <10 kg >10 kg

44% 42% 43% 64%

p=0.001

p=1.0

ppCRRT Data of Infants <10Kg: Factors Effecting Survival

Clinical Variable Survivors Non-Survivors P

Admission PRISM score 16 21 <0.05

GI/Hepatic disease 8% 31% 0.01

Multiorgan dysfunction 68% 91% 0.04

Pressor Dependency 36% 69% <0.01

Mean Airway Pressure 11 20 <0.001

Initial urine output (ml/kg/hr) 2.4 1.0 0.02

%Fluid Overload at Start 15% 34% 0.02

>10% Overload at Start 43% 71% 0.02

ppCRRT Data of Infants <10Kg: Survival by Return to Dry Weight

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Survivors Non-survivors

Dry Weight Achieved

Dry Weight Not Achieved

78%

35%

22%

65%

Infant CRRT at Children’s Hospital & Regional Medical Center, Seattle

Infant CRRT in Seattle: Overview

• Coordinated by nephrology

• Performed in infant/pediatric ICU

• Set up by dialysis nurses

• Run at the bedside by neonatology or critical care nurses

• Dedicated CRRT device– BM-25: 1999 – 2005– Prisma: 2005 - present

CRRT Access in the Neonate:What Works?

• Hemodialysis Line: 7 Fr double lumen

• Two single lumen lines:– 5 Fr catheters or introducers

• Umbilical lines:– 5 Fr UAC; 7 Fr UVC

• Leg position - be creative

• Tape on the skin - may need to get creative

PRISMA

• Dedicated CRRT device

• Highly automated

• Designed for ease of use at the bedside

CRRT Filter Sets for PrismaSurface

AreaPriming Volume

Membrane

M-10* 0.042m2 50ml AN-69

M-60 0.6m2 90ml AN-69

M-100 0.9m2 107ml AN-69

HF-1000 1.15m2 128mlPolyarylethersulfone

(PAES)

* Not available in US

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

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+

Simple Systems to Limit Likelihood of Bradykinin Release Syndrome

• Don’t prime on with blood

• Don’t use the AN-69 membrane

Thermal Regulation

• Hotline® blood warming tubing

• Place at venous return to patient

• Leave on at set temperature of 39 C

• Treat temp elevations if they occur

Infant CRRT in Seattle: CRRT Staffing

• Dialysis RN sets-up & initiates therapy

• PICU/IICU RN manages patient

• Nephrology/Dialysis RN on call 24/7

• Acuity assigned to pump as if a separate patient

• Staffing determined by acuity

Infant CRRT in Seattle: How to Handle a Rare Procedure

• Developed an Acute Initiation Checklist defining specific roles/actions for:– Infant ICU MD– Nephrology MD– Infant ICU RN– Dialysis RN– IV access MD

Acute Initiation Checklist: Example

Infant ICU Nurse• Time Zero:

– Move pt to room with dialysis water

– Get orders from resident for IV fluids to keep access open

• 20 – 40 min:– Meet MD; discuss RRT plan

• 60 – 120 min:– Meet ICU team

Dialysis Nurse• 10 – 60 min:

– Arrive and begin setup

• 20 – 40 min:– Meet MD; discuss RRT plan

• 60 – 120 min:– Complete prime; ready for

access– Begin RRT– Meet ICU team

Acute Initiation Checklist: Example

Nephrology MD• Time Zero:

– Contact dialysis nurse to start RRT urgently

• 10 – 20 min:– Bring catheters to ICU– Enter orders for RRT

• 20 – 40 min:– Meet ICU MDs & RNs,

discuss plan

• 60 – 120 min:– Present in ICU for initiation– Meet ICU team

IV Access MD• 10 – 30 min:

– Arrive and begin insertion of dialysis access

• 60 min (or when circuit is ready for Rx)– Complete insertion of access– Connect ports to heparin IV

solutions

Infant RRT: Summary

• All modalities of RRT possible for infants

• No modality is perfect

• Technical challenges can be met

• Careful planning with institution, program, and individuals improves care

• Cooperation, communication, and collaboration will increase our success

Thanks!