Cold-stored low-titer whole blood (WB) is becoming increasingly used as the preferred product for initial hemorrhagic shock resuscitation. The purpose of this study was to identify whether the current 21-day shelf life is the optimal duration for storage of WB, maintaining hemostatic efficacy.
Five units of fresh low-titer group O WB (non-leukoreduced) were acquired from our regional blood center. These units were stored at 4°C for up to 21 days as per current clinical storage guidelines in our emergency department. Hemostatic parameters were measured in vitro at 0 days, 7 days, 14 days, and 21 days. Assessments of hemostatic potential included cell count, rapid thrombelastography (r-TEG) and kaolin thrombelastography (TEG), multiplate impedance aggregometry, and calibrated automated thrombogram (CAT). Univariate analysis, including one-way analysis of variance with repeated measures, was performed (STATA 12.1).
Compared with baseline product (0 days), both platelet count and platelet function of WB showed sharp decreases at 7 days and again at 14 days. Platelet function deterioration was noted by r-TEG c (MA), TEG-MA, and multiplate arachidonic acid and adenosine diphosphate (all p < 0.001). With respect to clot initiation, r-TEG ACT and TEG R-time were similar over the 21-day shelf life (p = 0.058 and p = 0.620, respectively). Thrombin generation assessed by CAT demonstrated stable endogenous thrombin potential over the course of storage (p = 0.162), but increased peak thrombin generation and quicker time to peak generation after 7 days.
While the platelet function of WB degrades significantly at 7 days (and again at 14 days), clot initiation remains stable over time, and thrombin generation appears to be improved at 7 days. This study supports a current storage limit for cold-stored, low-titer WB of 14 days.