News
Ethylenediaminetetraacetic Acid (EDTA)-Dependent Pseudothrombocytopenia: A Case Report of an Incidental but Important Finding
Rod S. Hagerman D.O. Undersea, Dive, and Submarine Medical Officer, Commander Submarine Group Ten US Navy, Kings Bay Naval Submarine Base, Kings Bay, GA
Ethylenediaminetetraacetic acid (EDTA) is a commonly used anticoagulant in sampling tubes designed for determination of complete blood counts. Associated with this anticoagulant is a phenomenon that is well known to cause erroneous reports of low platelet counts by automated analyzers.
This phenomenon of EDTA-induced pseudothrombocytopenia has been reported rarely in both normal individuals and in association with a variety of diseases, such as infections with human immunodeficiency virus, rubella, and cytomegalovirus; autoimmune disorders; neoplastic diseases; thrombotic disorders; and possibly trauma. It occurs with an incidence of approximately 0.1% in the general population and has never been associated with hemorrhagic diathesis or platelet dysfunction. However, failure to recognize this form of Pseudothrom-bocytopenia (PTCP) may lead a subject with a normal platelet count, to be considered as if he had severe thrombocytopenia. Needless evaluations, canceled surgical procedures, avoidance of conduction anesthesia, unwarranted splenectomies, and undue patient expense and anxiety are all potential outcomes for an individual with this form of in vitro artifact. Since its initial description in 1969, this condition has become commonly associated with hospitalized patients, especially seriously ill ones. PTCP has also been reported, although less commonly in healthy subjects undergoing routine blood counts.
The following is an excerpt of a case study involving an otherwise healthy 18 year old male Naval Diver:
Upon reviewing his initial labs (Complete Blood Count) it was observed that there was a critical value of 34 x 103 platelets. The rest of the CBC was normal.
The patient was brought back into the exam room for a closer inspection of his integument for signs of petechiae or echymosis consistent with a platelet disorder. This follow up exam remained normal, and his history remained devoid of clues for easy bruising, gingival bleeding or bloody bowel movements.
After reinspection was complete, a microscopic review of the sample was conducted. Numerous megakaryocytes appeared to be present in each high power field, but upon further review, the finding was consistent with groups of thrombocytes tightly clumped together. The patient's blood was redrawn and run immediately. The follow up platelet count was normal at 219 x 103. The same sample was run again 10 minutes later and found to be 108 x 103. Again, microscopic exam revealed significant clumping.
Further studies determined that this abnormality occurred in all anticoagulant types but less severely in Sodium Citrate, the liquid anticoagulant in tubes for coagulation testing.
NOTE: Aculabs recommends that all suspect platelet counts be redrawn in blue-top tubes containing Sodium Citrate. It is already policy that, when the technologist finds a spurious result that does not agree with the patient’s previous platelet counts, a visual determination for platelet clumping is done and, if necessary, a redraw in Sodium Citrate.
To read the original article, go to the Publications & Articles section of our website.
MRSA Screening
MRSA is in the news for good reason. Infections by methicillin-resistant Staphylococcus aureus (MRSA) accounted for 22% of Staph Aureus infections in 1995, and by 2004, that percentage increased to 63%. MRSA is associated with significantly adverse outcomes and increased health care costs – especially in the geriatric population.
The first step to control is recognizing the MRSA colonized patient. This patient serves as a reservoir for spread of the disease within the health care environment.
Rapid pre-admission screening may improve control measures, because the traditional microbiological methods for MRSA screening are not immediately available.
If your facility has an interest in pre-screening for this very dangerous organism, Aculabs will respond by bringing the rapid screen in-house. We need feedback. If you are interested, please either email Dr. Khoury or call at 732-777-2588, ext. 5150.
Aculabs is always interested in participating in the care of your patient with the latest in technology and service.