Impact of Platelet Transfusion at Different Doses in Oncohematology Pediatric Inpatients and Outpatients: A Retrospective Study.

Background: Platelet (PLT) transfusion is an essential strategy to prevent bleeding in children with thrombocytopenia associated to cancer treatment. However, data on optimal pediatric dosing and transfusion thresholds are limited.

Methods: This retrospective study analyzed data from 607 pediatric patients with hematologic malignancies, nonmalignant disorders, and solid tumors who developed hypoproliferative thrombocytopenia during therapy. In the first phase (Objective 1), the effective response to transfusion (ERTR) was assessed following International Collaboration for Transfusion Medicine guidelines (ICTMG), comparing low-dose (1.1 × 10 PLT/m body surface area) transfusions for inpatients and medium dose (2.2 × 10) for outpatients. Transfusion thresholds were set at less than 10,000/µL versus 10,000-20,000/µL, and overall PLT concentrate consumption was analyzed. The second phase (Objective 2) examined the total number of transfusions per patient, incidence of major bleeding events, and bleeding-related mortality rates across dosing groups.

Results: ERTR ranged from 65% to 82%, with significantly higher rates in outpatients compared to inpatients. In outpatients with PLT less than 10,000/µL, the medium dose showed no significant advantage over the lower inpatient dose. Similar efficacy was observed between low (<10,000/µL) and high (10,000-20,000/µL) transfusion triggers, with no statistically significant difference in the incidence of major bleeding events across groups. The low-dose strategy was significantly associated with a reduction in PLT volume transfused compared to the standard expected dose.

Conclusions: These findings support the application of ICTMG in pediatric settings. The lower PLT dose for inpatients is safe and effective, providing benefits in resource utilization, while a higher transfusion trigger (20,000/µL) does not improve outcomes.