Pseudothrombocytopenia: incidence and strategy for resolution in clinical laboratory

ABSTRACT Introduction: Pseudothrombocytopenia is an important source of pre-analytical problems in clinical laboratory; therefore it must be correctly evaluated. Low spurious platelet counts can lead to misdiagnosis. Objective: This study aims to study the resolution of pseudothrombocytopenia in the laboratory routine of clinical laboratory by standardizing the use of vortexer. Methods: This is a cross-sectional, analytical, quantitative study based on experimental approach, involving 45 pseudothrombocytopenia samples divided into three groups and submitted to vortexing for 1, 2 and 3 minutes. Results: During the study, 28,435 blood counts were performed, and 56 (0.196%) of these samples confirmed platelet aggregates. The 2 and 3 minute times normalized the platelet count (greater than 150,000/µl) in two thirds of the samples tested. Platelets, hemolysis index, platelet distribution width (PDW) and mean platelet volume (MPV) presented statistically significant mean difference (MD) (p < 0.05) after vortexing at all times. Conclusion: The 2 and 3-minute times were the most effective in the resolution of pseudothrombocytopenia, however, the 2 minutes time should be preferred because it produced fewer effects on the erythrocyte membrane.