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Pediatric CRRT: Dialysis and Replacement Solutions. William E. Smoyer, M.D. Pediatric Nephrology University of Michigan. Introduction. Variety of CRRT solutions in use Few commercial options for CRRT fluid in some countries (i.e. USA) Major determinants Base composition
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Pediatric CRRT:Dialysis and Replacement Solutions William E. Smoyer, M.D. Pediatric Nephrology University of Michigan
Introduction • Variety of CRRT solutions in use • Few commercial options for CRRT fluid in some countries (i.e. USA) • Major determinants • Base composition • Location of preparation • Timing of preparation
Base Composition of CRRT Fluid • Replacement Fluid / Dialysate • Should be nearly physiologic (two exceptions) • 1) Cannot combine physiologic Ca++ and PO4-3 • 2) Need supraphysiologic HCO3- • Types of Solutions • Bicarbonate-based solutions (custom made) • Lactate-based solutions (pre-made)
Bicarbonate-Based CRRT Fluid • Generally preferred over lactate-based solutions • Can be used for replacement fluid or dialysate • Avoids need for conversion of lactate into bicarbonate • Not stable for long periods due to CO2 diffusion • More expensive than lactate-based solutions • Not widely commercially available • No marketed solutions in USA • Marketed as “Hemosol” in Canada and Europe
Bicarbonate-Based CRRT Fluid • Phosphorus-based Solution • Requires continuous calcium infusion • CaCl2 titrated to keep Ca++ at 1-1.3 mEq/L • Calcium-based Solution • Requires continuous phosphorus infusion • Na3PO4 at 1-2 mmol/kg/d
Bicarbonate-Based CRRT Fluid • Options for Therapy • Custom made in hospital pharmacy (most common) • Generated by hemodialysis machine 1 • Alternating Ca- and HCO3-based solutions (hourly) • 0.45% saline + 70 mEq/L NaHCO3 + 0-4 mEq/L KCl • 0.9% saline + 300 mg/L CaCl2+200 mg/L MgSO4 + 0-4 mEq/L KCl • “Four Bag” Method 2 • COMPASS Program 1 LeBlanc et al. Am J Kid Dis. 26:910, 1995 2 Mault et al. ASAIO J 30:203, 1984
Replacement Fluid or Dialysate Bicarbonate-Based Solutions
Lactate-Based CRRT Fluid • Stable for long periods • Commercially available • 1.5% peritoneal dialysate • Lactated Ringer’s solution • Baxter Premix Dialysate (only FDA-approved) • Less expensive than bicarbonate-based fluid • Generally used only for dialysate
Lactate-Based CRRT Fluid • 1.5% Peritoneal Dialysate (Not approved) • Advantages • Pre-made Can be obtained more quickly • Inexpensive • Disadvantages • Lactate may acidosis (liver failure, poor perfusion) • Dextrose is 1500 mg/dL and may hyperglycemia • Na is 132 mEq/L and may hyponatremia • K is 0 mEq/L and may hypokalemia • PO4 is 0 mEq/L and may hypophosphatemia
Lactate-Based CRRT Fluid • Lactated Ringer’s Solution (Not approved) • Advantages • Pre-made Can be obtained more quickly • Inexpensive • Disadvantages • Lactate may acidosis (liver failure, poor perfusion) • Dextrose is 0 mg/dL and may hypoglycemia • Na is 130 mEq/L and may hyponatremia • K is 4 mEq/L (? not desirable if treating hyperkalemia) • PO4 is 0 mEq/L and may hypophosphatemia
Lactate-Based CRRT Fluid • Baxter Premix Dialysate (Not for infusion) • Advantages • Pre-made Can be obtained more quickly • Inexpensive • Disadvantages • Lactate may acidosis (liver failure, poor perfusion) • K is 2 mEq/L and may hypokalemia • PO4 is 0 mEq/L and may hypophosphatemia
Dialysate 1.5% PD LR Baxter Glucose (mg/dL) 1500 0 100 Na (mEq/L) 132 130 140 K (mEq/L) 0 4 2 Cl (mEq/L) 96 109 117 Ca (mEq/L) 3.5 3 3.5 Phos (mg/dL) 0 0 0 Mg (mg/dL) 0.5 0 1.5 Lactate (mEq/L) 40 28 30 Osmolality (mOsm/L) 346 273 297
Location of CRRT Fluid Preparation • Prepared in hospital (custom made) • NaHCO3-based fluid • Prepared in dialysis unit • NaHCO3-based fluid (Hemodialysis machine) 1 • Prepared in ICU • NaHCO3-based fluid (“Four Bag” Method) 2 • Prepared commercially • Lactate-based fluid • NaHCO3-based (COMPASS) 1 LeBlanc et al. Am J Kid Dis. 26:910, 1995 2 Mault et al. ASAIO J 30:203, 1984
Timing of CRRT Fluid Preparation • Stock Solutions • Generally lactate-based • Less expensive • Hospal “Hemosol”(In Canada and Europe) • Immediate Use Solutions • All NaHCO3-based • More expensive
CRRT Fluids in Pediatric Programs • Both HCO3- and lactate-based solutions being used in USA • Most programs using HCO3-based solutions • Most programs using solutions made in hospital pharmacy • Few programs using Baxter Premix Dialysate • No programs using dialysate generated with hemodialysis machine
Summary • Variety of CRRT dialysate and replacement solutions available • NaHCO3-based solutions generally preferable • Lactate-based solutions less expensive and more readily available (usually dialysate only) • Custom-made solutions have risk of preparation errors • Need increased availability of standardized, pre-made NaHCO3-based solutions (esp. in USA)