Evaluation of the coagulation profiles of stored autologous whole blood using rotation thromboelastometry

Abstract

INTRODUCTION: Preoperative autologous whole blood (AWB) donation is performed to avoid perioperative allogeneic blood transfusion. In general, the main purpose of AWB donation is to preserve and replace the patient's red blood cells. The coagulation profile of stored AWB is unknown. We hypothesized that coagulation activity is maintained in stored AWB and investigated the coagulation profiles of stored AWB using rotation thromboelastometry (ROTEM) METHODS: After obtaining IRB approval and informed consent, 46 adult patients undergoing elective cardiac surgery were enrolled. Patients taking warfarin were excluded. AWB donation was conducted according to our institute's protocol. The collected AWB was stored in a refrigerator until reinfusion. Blood specimen for the study was drawn from the storage bag at reinfusion. Standard hematologic tests [fibrinogen (FNG), hemoglobin (Hb) levels, and platelet count (PLT)], and ROTEM analysis were performed using the same specimen. The ROTEM analysis consisted of INTEM (ellagic acid-activated coagulation profile), EXTEM (tissue factor-activated coagulation) and FIBTEM (EXTEM with platelet deactivation) tests, and clotting time (CT), clot formation time (CFT) and maximum clot firmness (MCF) were determined in each test. In order to investigate the effect of storage on FNG, the samples were divided into three groups with respect to storage duration (Group 1: within 10 days, Group 2: 11 - 20 days or Group3: longer than 21 days) and the FNG was compared among the groups. P<0.05 was considered to be statistically significant. RESULTS: In total of 141 AWB samples were analyzed. The mean duration for storage was 16.7±7.3 days (mean ± SD, range: 6-33 days). The mean Hb and FNG level was 10.6±1.1 g/dL, and 228.6±61.4 mg/dL, respectively. PLT was nearly zero in all samples. In ROTEM analysis, INTEM-, EXTEM- and FIBTEM-CT were significantly prolonged (288.7±85.5, 95.1±74.9 and 90.1±79.5 sec, respectively). CFT was not measurable in almost all traces. On the other hand, INTEM-, EXTEM- and FIBTEM- MCF were 14.1±5.2, 14.7±5.4 and 13.2±5.0mm, respectively. There was a strong correlation between FIBTEM-MCF and FNG (r=0.86) (Figure 1). There were no significant differences in FNG among the 3 groups (Group 1: Median 220, IQR=56.8, Group 2: Median 231, IQR=80.5, Group 3: Median 222 IQR=75.3) (Figure 2). CONCLUSIONS: In our study, ROTEM demonstrated fibrin polymerization activity in stored AWB, which strongly correlated with the fibrinogen level. Prolonged clotting time was considered to be due to the loss of platelet function. Our data suggest that clot formation ability except for platelet function is retained in AWB even after a long storage. (Figure Presented).