Underfilled K2EDTA Vacutainer on Automated Haematological Blood Cell Indices- To Reject or Reconsider?

Abstract

Introduction: The most common reason for rejection of blood samples in laboratory is because they are under-filled. Clinical and Laboratory Standards Institute (CLSI) guidelines state that blood vacutainers that contain either 10% higher or lower blood than the recommended volume must be rejected. Repeated phlebotomy has to be performed for such samples which can delay the turnaround time. Aim: To study the effects of underfilled K2EDTA vacutainers on automated haematology indices and compare them with the standard. Materials and Methods: This observational and comparative study was conducted at the department of pathology, Chettinad Hospital and Research Institute, Tamil Nadu for a duration of 6 months from January 2019 to June 2019. A 100 paired samples of underfilled K2EDTA vacutainers were compared with the standard for Complete Blood Count (CBC) analysis using BECKMAN COULTER LH 780 analyser. Statistical analyses was done using Statistical Package for Social Science (SPSS) software v.18 and paired student’s t-test. The p-value <0.05 was considered statistically significant. Results: All the parameters in the CBC showed comparable results between under-filled K2EDTA vacutainers of 1 mL blood volume and standard 3 mL blood volume vacutainers. There was no significant variation in statistics even when the blood volume is as low as 1 mL which is 67% less than that of the recommended volume. Conclusion: Blood samples which are under-filled upto 67% less than recommended volume, i.e. upto 1 ml can be accepted for CBC analysis using BECKMAN COULTER LH 780 analyser. Therefore, the CBC data obtained from the under-filled vacutainers can be used for clinical diagnosis in situations where repeat blood collection is challenging or impossible.

Keywords

• automated analyser
• blood volume
• complete blood count
• ethylene diamine tetra acetic acid (dipotassium salt)
• underfilling