Changes in platelet transfusion thresholds utilized in the NICU since PlaNeT-2

Abstract Background Use of prophylactic platelet transfusions in the neonatal setting is a common practice due to concerns about bleeding despite evidence of a developmental mismatch with transfusion of adult platelets. The Platelets for Neonatal Transfusion-Study 2 (PlaNeT-2) published in January 2019 showed that using higher platelet thresholds (50 x 109/L) was associated with more adverse outcomes and no improvement in bleeding events compared to lower platelet thresholds (25 x 109/L). Following this trial, implementation of a lower threshold was provider dependent as there were no changes made to the neonatal intensive care unit (NICU) institutional policies. Our goal was to determine if there were any overall changes in individual clinical practice with thresholds used for platelet transfusions in our NICU and number of transfusions per patient. Methods Our center has a 52 bed level IV NICU that specializes in care for critical and/or preterm infants. We performed a retrospective review from 2017 to 2023 of patients admitted in the NICU who received platelet transfusion and had an available platelet count in the 12 hours prior to the transfusion. Results There were 272 platelet transfusions given to 107 unique NICU patients who had platelet counts available. There were 66 transfusions given to 32 patients pre-PlaNeT-2 (2017-2018) and 206 transfusions given to 75 patients post-PlaNeT-2 (2019-2023). The average platelet count pre-PLaNeT-2(2017 to 2018) was 43 x 109/L (SD±24 x 109/L) and post-PLaNeT-2 (2019 to 2023) was 36 x 109/L (SD±21 x 109/L, p=0.03). Prior to PLaNeT-2, 26% of platelet transfusions were for platelet counts ≤ 25 x 109/L and 35% were for platelet counts between 51 to 100x9/L. Post PLaNeT-2 the percentages changed to 35% and 21% respectively. The percentage of transfusions occurring for platelet counts between 26 to ≤50 x 109/L was 38% and 44%, respectively. The number of platelet transfusions per year did not decrease significantly after the PLaNeT-2 trial (average of 33/year versus 41/year, p=0.5). The number of transfusions per patient before and after PLaNeT-2 did not change (2.1 transfusions per patient versus 2.6 transfusions per patient, p=0.3). Conclusion Platelet thresholds utilized in our center decreased after the PLaNeT-2 trial with less transfusions occurring for platelet counts greater than 50 x 109/L. Although thresholds decreased, the number of transfusions per year and the number of transfusions per patient did not significantly change. Further studies are needed to understand changes in patient outcomes and platelet utilization in the NICU.