How I use platelet transfusions.

Platelet transfusions are commonly administered for the prevention or treatment of bleeding in patients with acquired thrombocytopenia across a range of clinical contexts. Recent data including randomized trials have highlighted uncertainties in the risk-benefit balance of this therapy. Hemovigilance systems report that platelets are the most frequently implicated component in transfusion reactions. There is considerable variation in platelet count increment following platelet transfusion, and limited evidence of efficacy for clinical outcomes including prevention of bleeding. Bleeding events commonly occur despite applying different policies for platelet transfusion prophylaxis. Platelet transfusions have been implicated in worsening lung injury, multi-organ failure, and paradoxically, more bleeding. The underlying mechanisms of harm reported in randomized trials might be related to the role of platelets beyond haemostasis, including mediating inflammation. Research supports the implementation of a restrictive platelet transfusion policy. In some patients, such as autologous stem cell transplantation, a no-prophylaxis policy may be safe (i.e. only if bleeding complications arise). Research is needed to determine the optimal thresholds for transfusion before invasive procedures or major surgery (e.g. laparotomy) in critical illness, and on better understanding the role of alternatives to platelet transfusion. Platelet transfusion policies should move towards a risk-adapted approach that does not solely focus on the platelet count.