Complications of Pediatric CRRT

1
Complications of Pediatric CRRT

• Theresa A. Mottes RN
• Pediatric Dialysis/Research Nurse
• C.S. Mott Childrens Hospital
• University of Michigan

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Complications of Pediatric CRRT

• Temperature instability
• Hemodynamic instability
• Anticoagulation Risk
• Circuit/Access Complications

3
Factors effecting hemodynamics

• Patient Volume Status
• Ultrafiltration Rate
• patients hemodynamic
• typically vasopressor dependent
• patients intravascular volume
• Ultrafiltration Rate
• 1-2ml/kg/hour net ultrafiltration
• absolute necessity to control ultrafiltration
• error of accurate ultrafiltration monitoring

4
RESULTS(Smoyer et al, CRRT 1997)
Trilogy Pump Accuracy over Range of Flow Rates
Error
IV Pump Flow Rate (ml/hr)
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Ultrafiltration accuracy2.8 kg infant on PRISMA
Prescription BFR 30 mls/min Dx FR 300 mls/hr
Ccs/hr
Hour of Therapy
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Factors effecting hemodynamics

• What now?
• Hourly assessment of Intake and Output
• Hourly Ultrafiltration calculations
• adjusting for pump error
• Accurate measuring of Ultrafiltration
• Close monitoring of hemodynamics
• Accurate daily weight

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Factors effecting hemodynamics

• Calculation for Pump Error

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Factors effecting hemodynamics

• Vasopressor clearance
• Vasopressor agents all have in common a small
  molecular weight and minimal protein binding
• Epinephrine
• Norepinephrine
• Dopamine
• Dobutamine

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Factors effecting hemodynamics

• Vasopressors
• Due to proximity of infusion
• be aware of infusing vasopressor agents in
  immediate proximity to the arterial port of the
  hemofiltration machine
• potential for recirculation
• effects delivery and clearance

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Intravascular Blood Volume

• lt 10 kg 80 ml/kg
• e.g. 8 kg infant 640 ml intravascular volume
• gt 10 kg 70 ml/kg
• e.g. 20 kg child has 1.4 liter intravascular
  volumeBlood
• Priming Hemofiltration Circuit
• Recommended when circuit volume gt 10 of
  patients intravascular blood volume

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Anticoagulation

• Heparin
• Citrate
• None

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Circuit Complications

• Circuit Clotting
• Inability to ultrafiltrate desired amount
• Increasing Access/Return Pressure
• Inadequate clearances
• Observe clotting in filter/ tubing

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Clotting with CVVH vs CVVHD(Mottes et al, CRRT
1999)
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Flow Rates

• Blood
• 5-10 ml/kg/min keeping venous pressure under 200
  mm Hg
• Dialysate/Replacement fluid
• 2 liters/1.73 m2/hr
• (extrapolation of adult data)

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Access Complications

• What is the correct access?
• One that works

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In Flow Difficulties

• Obstruction or clot on the return line
• high intrathoracic pressure with HIFI
• up against the vessel wall
• Clamp on inflow
• Access kinked at skin site
• Consider reversing or changing access

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Out Flow Difficulties

• Clamp on access/arterial line
• Inflow port up against vessel wall
• Patient dry eg with femoral site
• High of blood flow requirements based upon flow
  ability of access
• Consider
• reverse flow, change access, decrease blood flow
  rates