Efficacy and Safety of Vortexing as a Practical Solution for Resolving Platelet Clumping in hematology laboratories

Platelet clumping is a pre-analytical artifact that leads to spurious thrombocytopenia, complicating laboratory interpretation and triggering unnecessary clinical interventions. Vortexing has been proposed as a corrective measure, yet the optimal duration, its applicability to transported samples, and its impact on WBC and RBC parameters remain poorly defined. This study aims to evaluate the efficacy and safety of vortexing across different durations to establish it as a standardized intervention in hematology laboratories.

A total of 730 EDTA-anticoagulated blood samples were analyzed. Samples were vortexed at 3200 rpm for 30 s, 1, or 2 min, using a fixed-speed vortex mixer. Platelet counts and interpretative messages were compared before and after vortexing using the Sysmex XN-10 platform. Stability of WBC and RBC parameters was also assessed.

Vortexing significantly reduced platelet clumping flags, with 66% overall resolution and the highest effect in the 101-150 × 10⁹/L group (74%). Platelet counts improved across all durations, with 2 min yielding the highest median increase (+39.0 × 10⁹/L, p = 2.70 × 10^-12). The Kruskal-Wallis test confirmed statistically significant differences among vortexing durations (p = 1.24 × 10^-5). WBC and RBC parameters remained stable post-vortexing, supporting the method's safety.

Vortexing is a reliable, reproducible, and practical method for resolving platelet clumping in EDTA samples without compromising sample integrity. Its implementation can reduce redraws, minimize manual smear reviews, and streamline sample processing in high-volume hematology laboratories.