Platelet transfusion improves coagulation parameters for at least 4 hours after platelet transfusion. (Image source: Thinkstock)

Platelet transfusion improves coagulation parameters for at least 4 hours after platelet transfusion. (Image source: Thinkstock)

The risk of bleeding following invasive procedures is increased in patients with thrombocytopenia or bone marrow failure. Such patients may receive platelet transfusions to reduce bleeding before invasive procedures or surgery.  How long before a procedure are platelet transfusions effective?

Dr. Thomas Kander, Department of Intensive and Perioperative Care, Skåne University Hospital and Lund University, Lund, Sweden, and coauthors took a novel approach to assess the clinical impact of prophylactic platelet transfusion in this before-and-after study of 39 patients with bone marrow failure scheduled to receive prophylactic platelet transfusion prior to placement of a subclavian central venous catheter.  The results are of their study are published in a future edition of Anesthesia & Analgesia in the article titled “The Effect and Duration of Prophylactic Platelet Transfusions Before Insertion of a Central Venous Catheter in Patients with Bone Marrow Failure Evaluated with Point-of-Care Methods and Flow Cytometry.”

The authors used traditional platelet and clotting factor studies as well as viscoelastic testing (ROTEM®) before platelet transfusion, 1 hour after transfusion,  and 4 hours post-transfusion.  They found an increase in the mean platelet count from 24×109/L to  42×109/L one hour after transfusion, and this increase was sustained at 4 hours.  Maximal clot firmness increased and clotting time decreased following transfusion.  The authors used flow cytometry to study the function of individual platelets; the results were mixed with no broad trend, but overall there was little change.  The authors concluded that platelet transfusion improves coagulation parameters for at least 4 hours after platelet transfusion in this population through an increase in platelet count rather than a change in platelet function.

The findings of this study will be of interest to anesthesiologists caring for thrombocytopenic patients.  While the platelet count threshold at which a prophylactic transfusion is indicated is highly controversial, it is at least reassuring to know that platelet transfusion improves whole blood clotting parameters, and continues to do so over at least 4 hours post-transfusion.