Splitting apheresis platelets as a contingency measure for inventory shortages.

Background: Splitting apheresis platelet (PLT) units increase available inventory during shortages. The impact of prolonged storage in gas-impermeable aliquot bags on PLT quality in vitro and transfusion outcomes in patients remains uncertain.

Study design and methods: We assessed in vitro PLT quality and thromboelastography (TEG) in PLTs stored for 8 or 24 h in aliquot bags compared with baseline (T0). Retrospective assessment of response (PLT increment and corrected count increment (CCI)) was conducted among adults (≥18 years) transfused with split platelet units from January 2021 to June 2022.

Results: No differences were observed in PLT and white blood cell (WBC) counts, mean platelet volume, or TEG parameters during storage, except for an increase in TEG R time (mean ± SD) at 24 h (6.1 ± 0.5 min) compared to T0 (4.4 ± 0.8 min), p = 0.0031 one-way ANOVA. Eighty-one patients were transfused 119 split units with a median [IQR] PLT yield of 2.1 × 10¹¹[1.9 × 10¹¹ to 2.3 × 10¹¹] and storage duration of 1.6[0.7-9.1] h. The overall median PLT count increment was 6.0 × 10³/uL and CCI was 5.0 × 10³, correlating negatively with split unit storage duration (Spearman rho = -0.218, p = 0.017). Compared with split transfusions of pathogen-reduced (PR) PLTs, non-PR splits were associated with higher median platelet count increments (7.0 × 10³/μL vs. 4.0 × 10³/μL, p = 0.0263 Mann-Whitney U) and higher CCIs (6.5 × 10³ vs. 3.9 × 10³, p = 0.0116 Mann-Whitney U) despite no differences in PLT yields (2.1 × 10¹¹/μL vs. 2.1 × 10¹¹/μL).

Discussion: Storing PLTs in aliquot bags for 8 or 24 h does not adversely affect their quality in vitro. Splitting apheresis PLTs are feasible for adult transfusions during shortages. It may be advisable to prioritize non-PR PLTs for splitting given improved patient responses.