Minimal impact of anticoagulant on in vitro whole blood quality throughout a 35-day cold-storage regardless of leukoreduction timing

Hemostatic function, immunomodulatory capacity, and effects of lipemia in cold-stored whole blood

BACKGROUND

Whole blood (WB) is increasingly being used for resuscitation of trauma patients. Although platelet-, red blood cell (RBC)- and plasma-specific parameters in cold-stored WB are well characterized, there has been limited investigation of biological response modifiers (BRMs), which may induce adverse reactions in recipients. The aim of this study was to evaluate the quality and function of RBC, platelets, plasma proteins, and BRMs in cold-stored WB during storage.

METHODS

WB (n = 24) was collected into collected into citrate-phosphate-dextrose (CPD) anticoagulant, held overnight, processed through a platelet-sparing filter, and stored at 2-6°C for 21 days. RBC, platelet, coagulation factor quality and function, and BRM concentrations were measured throughout the duration of storage.

RESULTS

WB was effectively leukoreduced, with 99.98% reduction in leukocyte count and 81% platelet count recovery following filtration. Five WB units were significantly lipemic, with a visible lipid layer appearing after being cold storage overnight. These were more turbid with higher hemolysis compared to non-lipemic units (p = .023). Despite a decrease in platelet count during storage (p < .001), hemostatic function as measured by thromboelastography was maintained for at least 21 days (R time and maximum amplitude; both p < .001). There was a significant increase in PF4, CD62P, and RANTES during cold storage (all p < .001).

DISCUSSION

WB retains hemostatic potential for at least 21 days of cold storage, and with further development, may be suitable for transfusion in Australia. Before implementation in Australia, quality control measures for lipemia and hemolysis would need to be defined as part of our manufacturing processes.

Expired blood transfusion and mortality outcomes in combat trauma patients

BACKGROUND

Expired blood can be transfused if clinically indicated but outcome data do not exist. We hypothesized that modestly outdated blood can effectively support a hemorrhaging patient until surgical control is achieved. This study assessed whether expired blood was associated with mortality in combat trauma patients.

STUDY DESIGN AND METHODS

A retrospective analysis of Armed Services Blood Program and Department of Defense Trauma Registry databases evaluated combat casualty records (2001-2023). The intervention of interest was transfusion of at least one unit of whole blood (WB), red blood cells (RBC), or platelets within one week past expiration. The outcome of interest was mortality at discharge. A control cohort that only received in-date blood was matched to the treatment cohort for logistic regression analysis.

RESULTS

One hundred patients received expired RBCs (86), WB (11), and platelets (3). Mortality at discharge was 11.6% for expired RBC recipients and 13.4% for the control cohort (p = .97). After adjustment for injury severity, expired RBCs were not associated with mortality (OR = 0.40 [95% CI, 0.14-1.16]; p = .09). Of 10 patients who received the most expired RBCs by volume or storage duration, two were deceased at discharge. All 14 expired WB and platelet recipients were alive at discharge, but sample sizes were underpowered for regression analysis.

DISCUSSION

Transfusion of modestly outdated RBCs was not associated with mortality in combat trauma patients. Expired WB and platelet recipients did well, but sample sizes were too small to draw significant conclusions. Expired blood should be further investigated for possible use in extenuating circumstances.