Background/Case Studies: A proposed solution to intermittent platelet (Plt) shortages has been to more aggressively split apheresis collections to produce additional, lower-content units. A 17% stated decrease in allowable content reflects the difference between the current lowest approved dose (3.0 [all values x10^11 Plts/unit unless specified]) and the suggested lower limit (2.5). The clinical impact of lowering platelet dose, however, may depend upon increments clinicians expect from currently available units. In 2002, only ~16% of distributed units from our blood center were requested to be pathogen-reduced (PRT). We collected data on the remainder of distributable Trima apheresis Plts in plasma undergoing large volume delayed [≥48h] sampling (LVDS48) testing. At present, few of our hospitals accept specially-labeled units with contents 2.5-2.9 ( < 0.1% of collected units).
Study
Design/Methods: The eProgesa computer system was queried for quantities and contents of Plts with single unit (unsplit) component codes, and those with 1st-4th container split product codes. Content was calculated from the Sysmex XE-2100D concentration and product volume. Collections are split into 2 units with post-sampling contents 6.2-9.2, into triples at contents 9.3-12.3, and into quads at contents ≥12.4. Only distributable units ≥3.0 are labeled Apheresis Platelets, Leukocytes Reduced. Trima concentration targets are ~1,575/μL for triples, ~1,250/μL for LVDS48 doubles (~1,650 at sites producing some PRT Plts), and 1,500/μL for singles.
Results/Findings: In 2022, 75.0% of collections were split into 2-4 units (51.8% double, 21.7% triple, 1.5% quad). Split collections yield 87% of distributable units. The mean content(SD) of all labeled units was 3.70(0.59), median(IQR) 3.6(0.6). The mean content(SD) of unsplit units was 4.59(0.89) and median(IQR) 4.5(1.4), with a bi-modal distribution around 4.1 and 6.2 (Figure). The 29.6% of single units with contents >5.1 to the highest-observed content of 7.9 with this product code (3.7% of all units) require storage in 2 connected bags. The mean content of split units was 3.57(0.38), median 3.5(0.5), and mode 3.4, with a positively-skewed distribution (Figure). Median product concentration for all units was 1,573(270)/μL. Conclusions: If 75% of low-yield units have contents 2.7-2.9, this represents a significant reduction from the IQR of 3.3-3.9 for units currently labeled as Apheresis Plts, a ~30% reduction at content 2.5 versus the current median 3.6. A small, expected decrease in non-procedural prophylactic intertransfusion intervals might be an acceptable exchange for greater Plt availability. The utilization impact for massive hemorrhage and most especially, periprocedural count-targeted transfusions requires additional study.
Importance of research: Integration of low-yield platelet units into clinical practice requires accurate information about the current content and concentration of Apheresis Platelets, Leukocytes Reduced, required to contain ≥3.0x10^11 Plts. We characterized LVDS48 units offered by a large blood center.
