Hyperammonemia, Neonatal — Continuous Renal Replacement Therapy (CRRT) — Clinical Pathway: Emergency Department and ICU

Neonatal Hyperammonemia Clinical Pathway — PICU and Emergency Department

Continuous Renal Replacement Therapy (CRRT)

  • High ammonia levels (> 500 μmol/L) require rapid clearance to minimize neurotoxicity and other morbidities.
  • Once child has been identified as needing CRRT to treat hyperammonemia, Nephrology will place orders for dialysis treatment-related prescriptions
Anticoagulation
PICU and Nephrology teams discuss to determine optimal anticoagulation based on individual child factors
  • Heparin
    • Used for ECMO children
  • Citrate
    • Requires additional central venous access points for calcium infusion
    • Monitor liver function
Dialysis Prescription Recommendations Ordered by Nephrology
Goal:
Maximize solute clearance for hyperammonemia, adjusting dialysate and replacement fluid as needed
  • Aim for dialysis/replacement flow rate of 8,000 mL/h/1.73m2 (1,000 mL/h) with a blood flow rate of at least 30 mL/min1
  • Consider adding phosphorus to dialysate and/or maximize in parenteral nutrition due to rapid clearance of solutes
Child Preparation for CRRT Initiation
  • Recommend achieving ionized calcium level of > 1.2 before CRRT initiation to help with child stability during initiation
Bedside RN Coordination
  • Ensure correct equipment and emergency medications available at bedside to initiate treatment
    • Calcium
    • Sodium Bicarbonate
    • Epinephrine
    • Dialysis warmer
    • Continuous temperature monitoring
  • If using heparin for CRRT anticoagulation, initiate ACT protocol
    • Gather supplies for frequent ACT's at bedside:
      • 1 ml syringes, alcohol wipes, 25 G needles
Blood Prime Requirements
Circuit for CRRT will need to be blood primed to prevent hemodynamic shifts in initiating therapy in these small children
  • Partner with Dialysis nursing on call to facilitate set-up of CRRT circuit, including blood for circuit prime.
  • Ensure active type and screen has resulted
    A second type and screen is required as a confirmation
  • Bedside RN should contact blood bank to ensure blood prime is prepared in a bag-not a syringe
Ongoing Management
  • While on CRRT, Metabolism Team will determine need for continuing amino acid and/or nitrogen-scavenger therapy to prevent rebound hyperammonemia.
  • Joint decision between Nephrology, Metabolism, and the PICU will determine when to trial off dialysis support and continue with medical therapy alone.

Reference

  1. High-dose Continuous Renal Replacement Therapy for Neonatal Hyperammonemia