Pseudothrombocytopenia in perioperative patient: A significant laboratory artifact
A 37-year-old euglycemic and normotensive male was found to have thrombocytopenia on his routine perioperative check-up before elective implant removal surgery. The orthopedic surgeon had cancelled his surgery and he was referred to Emergency Department for further work up. There was no history of fever, rash or bleeding tendency. He was not on any concurrent medications or herbal agents. His family history was non-significant. Physical examination was unremarkable. A complete blood count with standard EDTA, which revealed white blood cell count of 6.0 × 103/mm3, hemoglobin of 14 g/dL and platelets of 4.0 × 103/mm3 by automated counter. A peripheral blood smear prepared from the same blood showed clumping of platelets. The coagulation profile, electrolyte levels, liver, renal and thyroid function tests, autoimmune screens, C-reactive protein and tumor markers were within normal range. Human immunodeficiency virus and hepatitis serology were negative. Chest radiography and abdominal ultrasonography did not reveal any abnormality. A repeat analysis of blood anticoagulated with citrate revealed a platelet count of 2.5 × 103/mm3 with normal distribution in the peripheral smear. The patient was diagnosed as pseudothrombocytopenia due to EDTA induced platelet aggregation (EIPA) and hence, further treatment or blood work was not initiated. The patient's surgery was rescheduled and performed without any complication. The surgical site showed no abnormal bleeding and his subsequent platelet counts during his post-operative period drawn in EDTA tubes constantly reported as thrombocytopenia.