Custom Sodium Citrate Tubes in Neonates Effective March 26th, 2018, all Providence Rapid Response Laboratories attending neonates patients will modify their practices regarding custom Sodium Citrate drawing containers to avoid unnecessary blood draws.

Spurious results may occur when a value is above 55%. This is because the ratio of anticoagulant to plasma varies with packed cell volume. To accurately report coagulation factor testing, the amount of sodium citrate must be adjusted according with the patient’s hematocrit. The clinical laboratories at Providence in Oregon has a procedure outlining the detection and handling of coagulation specimens with elevated and the process to adjust the amount of citrate in coagulation specimens when the hematocrit is above 55% in adults or 70% in neonates.

For neonates: In the NICU, 1 mL citrate specimens are drawn to avoid drawing large volume of blood and cause detrimental effects in the neonates. When using adjusted citrate volumes in 1 mL tubes there is a small error observed. This error may be comparable to the imprecision of the testing and the variability on the normal reference interval. Based on this information, adjusting the citrate volume will only be performed if the hematocrit is above 70%.

For pediatric and adults: If your patient’s hematocrit is above 55%, we will continue our practice and may ask to redraw using a custom amount of sodium citrate. The laboratory will continue its current practices for recollection.

Adjusting the amount of citrate for specimens with hematocrit lower than 20% or in the presence of severe anemia is not recommended. For additional information, please contact Drs. Veronica Luzzi or Matthew Frank at Client Services at (503) 215-6555.

References:

1. Clinical and Laboratory Standards Institute (CLSI). Collection, Transport, and Processing of Blood Specimens for Testing Plasma-Based Coagulation Assays and Molecular Assays; Approved Guideline—Fifth Edition. CLSI Document H21-A5 (ISBN 1-56238-657-3). Clinical and Laboratory Standards Institute, 940 West Valley Road, Suite 1400, Wayne, PA 19087-1898 USA, 2008. Mariar RA, et al. Effect on routine and special coagulation testing values of citrate anticoagulant adjustment in patients with high hematocrit values. Am J Clin Pathol. 2006: 126:400-405. 2. Mariar RA, et al. Effect on routine and special coagulation testing values of citrate anticoagulant adjustment in patients with high hematocrit values. Am J Clin Pathol. 2006: 126:400-405 3. Goodwin AJ. Q & A: Should a patient with a hematocrit greater than 55 percent be redrawn for correction always or only when and partial prothrombin time are elevated? CAP Today. August 2016