Platelets are the good little minions of hemostasis. In their absence, invasive procedures develop additional risk, ranging from minimal to clinically important, and the mitigation strategy ranges from avoidance, the alternative procedural techniques, to prophylactic platelet transfusions. Platelets, like any blood product, are associated significant risks, not limited to acute lung injury, transfusion-related circulatory overload, allergic reactions, and more.
This prospective, randomized trial evaluated whether, in patients with thrombocytopenia, a platelet transfusion was necessary before central venous catheter placement. Enrolled patients included those undergoing in-hospital, ultrasound-guided CVC placement, primarily “regular” CVCs, placed into the internal jugular and subclavian veins. Patients randomized to transfusion received one unit of platelet concentrate roughly one hour prior to the procedure. The primary outcome was CVC-related bleeding, graded on a scale of 0 to 4, where Grade 3 and 4 bleeding was associated with significant intervention.
In those receiving a platelet transfusion prior to CVC placement, grade 3 and 4 bleeding was seen in 4 of 188 (2.1%) of patients, compared with 9 of 185 (4.9%) of those who did not receive a transfusion. There were also excesses of Grade 1 and 2 bleeding in those who did not receive a transfusion prior to the procedure. Secondary subgroup analyses were underpowered to determine if any specific subgroups were at higher risk, but it is reasonable to suggest the risk may increase as the initial platelet count decreases, while internal jugular placement was the safest site.
The cost of this initial protection was, obviously, quite a number of platelet transfusions. Owing to observed bleeding complications, the mean number of units of platelets transfused following CVC placement was much higher in the group not having received a prophylactic transfusion. However, when the initial prophylaxis is taken into account, the transfusion cohort received more than double the platelets within 24 hours of the procedure. Red blood cell transfusion was not different between groups, and other observed length-of-stay and mortality outcomes are probably not reliably different.
The trial is presented as “negative”, as the differences in serious bleeding fail to meet the pre-specified endpoint for non-inferiority. The authors, however, make an appropriately nuanced interpretation regarding the sliding scale of risk for bleeding, and suggest lower platelet counts, and those likely to require a platelet transfusion in the near future for other clinical indications, represent the most judicious population in which to consider prophylactic transfusion.
“Platelet Transfusion before CVC Placement in Patients with Thrombocytopenia”