The Influence of Bleeding on Trigger Changes for Platelet Transfusion in Chemotherapy-Induced Thrombocytopenic Patients

Abstract 1260

The optimal threshold for prophylactic platelet transfusion in hypoproliferative thrombocytopenic patients has been evaluated in multiple studies involving hematology and oncology patients. For patients without additional risk factors for bleeding, a trigger of 10 × 10⁹/L is now accepted as safe and recommended in different guidelines. In the original studies, platelet transfusion above this trigger was allowed according to variable predetermined risk factors for bleeding. But, no studies have evaluated the clinicians' decision-making process leading to a change in the trigger for platelet transfusion. We report on the evaluation of trigger change for platelet transfusion following an initial threshold of 10 × 10⁹/L and the relation with the presence of bleeding according to WHO grades and systems. Eighty-patients that were enrolled at University of Minnesota Medical Center for the previously published SPRINT Trial represent the patient population for the current analysis. Seventy-four patients (93%) had a starting trigger for platelet transfusion of 10 × 10⁹/L and the majority (46/74; 62%) had an increase in their trigger during their hospitalization. Adherence to this starting trigger varied widely between treatment groups. Only a minority of patients treated with chemotherapy alone (3/12; 25%) and autologous transplant (6/15; 40%) had a change in their initial trigger of 10 × 10⁹/L in contrast to the majority of allogeneic transplant patients (37/47; 79%) (p=0.001 compared to chemotherapy group and p=0.009 compared to autologous transplant group, respectively). The main reason reported by clinicians for a change after a starting trigger of 10 × 10⁹/L was bleeding (32/46; 70%). However, trigger changes were not associated with more clinically significant bleeding. The occurrence of WHO grade 2–4 bleeding was very similar in patients with a trigger change and patients without a trigger change (51% and 54%; p=1.00). Even when limiting the analysis to trigger changes for a bleeding reason the overall distribution of the highest bleeding grades (WHO grade 0–4) leading to that change was similar to the highest bleeding grades of patients without a trigger change (p=0.205). Clinicians were influenced by the WHO organ system in which bleeding occurred when making their decision whether or not to raise the trigger for platelet transfusion. There was an overrepresentation of grade 1 mucocutaneous bleeding leading to an increase in the trigger (62% of the cases). And, there was an overrepresentation of grade 2 genitourinary bleeding not leading to an increase in the trigger (57% of cases). In conclusion, having a universal trigger of 10 × 10⁹/L for platelet transfusion in hypoproliferative thrombocytopenic patients is probably not adequate because of the diversity of the patient population and their respective bleeding risk factors. Also, these multiple complicating factors for bleeding that lead to trigger changes need better validation to support clinicians in their decision-making process when addressing the optimal trigger for platelet transfusion. Otherwise, a seemingly valid trigger of 10 × 10⁹/L becomes useless if misused or changed for any kind of reasons.