Abstract: FR-PO076
A Simplified, Weight-Based CVVHDF-RCA Prescribing Algorithm That Works Regardless of Citrate Metabolism Is Verified in Ex Vivo Simulations
Session Information
- AKI: Clinical Outcomes, Trials
November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Szamosfalvi, Balazs, University of Michigan, Ann Arbor, Michigan, United States
- Yessayan, Lenar Tatios, University of Michigan, Ann Arbor, Michigan, United States
Background
In practice great variations in CRRT-RCA protocols exist with many centers avoiding RCA in severe shock and liver failure patients and most small intensive care units avoiding RCA completely. Complications of hypocalcemia and hypercalcemia, hypo- or hypernatremia, and metabolic- alkalosis or acidosis are reported with most protocols. We present a new, simplified approach to CRRT-RCA prescribing and demonstrate in an ex vivo simulation system devoid of citrate metabolism that all electrolyte complications due to CRRT-RCA can be avoided by careful protocol design.
Methods
We used a recently FDA-approved CRRT system to deliver CVVHDF-RCA in an ex vivo system (Figure 1). IV pumps delivered infusions of urea/creatinine, ACDA and calcium. PRBCs and plasma filled the CRRT circuit and reservoir to target Hct. We tested QB 20, 40, 60 ml/min and Hct 45, 33, 21. Commercial 140Na, 4K, 35HCO3, 1.5Mg, 0Ca, 5.5mMGlu CRRT fluid spiked to phosphate 4.2 mg/dL (1.5 mM) was used. A 136 mM CaCl2 solution was prepared in 0.9% saline. Dosing weight (DW) = round(weight)+10 if patient weight (Kg) <100 otherwise round (weight)+20 (kg). QB (ml/min) = 0.5 * DW. ACDA (ml/h) = 2.5* QB, QDialysate (ml/h) = 30 * QB, QReplacement (ml/h) = 10 * QB and QCa (ml/h) about 0.7 * QB and Qurea (ml/h) = QB. Blood and fluid samples were collected and analyzed by I-stat and in the laboratory.
Results
We had no CRRT alarms. The reservoir iCa was 1-1.3 mM. All circuit iCa was < 0.25 mM. Reservoir Na was 135-140 and other major electrolytes were at physiologic values. Single pass citrate removal was 80-90%. Effluent dose was 25-35 ml/kg/hour.
Conclusion
We showed that a simple approach to CVVHDF-RCA prescribing using commercially available equipment achieved target effluent dose, below 0.25 iCa in the CRRT circuit and normal iCa and systemic electrolytes in the patient without any concern for citrate metabolism.
Funding
- Private Foundation Support