Thromboelastometric evaluation of coagulation profiles of cold-stored autologous whole blood: A prospective observational study

Abstract

Preoperative autologous blood donation is a well-established procedure to reduce the need for allogeneic blood transfusion. We hypothesized that coagulation activity is maintained in cold-stored whole blood, because the fundamental polymerization properties of fibrin are preserved.Fifty adult patients who underwent elective cardiothoracic surgery were enrolled.Autologous whole blood collected 2 to 4 times at almost 1-week intervals before surgery was stored at approximately 4°C until reinfusion at the time of surgery. Blood samples were drawn just before reinfusion, and rotational thromboelastometry variables and fibrinogen levels were measured.A total of 158 samples were analyzed. The mean duration of cold storage was 16.7 ± 7.4 days (range: 6-33 days). Platelet counts were very low due to collection through a leukoreduction filter. The mean fibrinogen level was 2.3 ± 0.6 g/L. Amplitude at 10 minutes after CT (A10), amplitude at 20 minutes after CT (A20), and maximum clot firmness (MCF) values as determined by FIBTEM analysis were 10.8 ± 3.8, 12.2 ± 4.2, and 13.1 ± 4.7 mm, respectively. Fibrinogen levels were strongly correlated with A10, A20, and FIBTEM-MCF values (ρ = 0.83, P < .0001, ρ = 0.84, P < .0001, ρ = 0.85, P < .0001, respectively). Fibrinogen levels were not correlated with the duration of cold storage (ρ = 0.06, P = .43).The results of the present study demonstrate that fibrin polymerization occurs in cold-stored autologous whole blood, and that such activity is strongly correlated with fibrinogen levels. Furthermore, our data suggest that cold-stored leukoreduced autologous whole blood retains fibrin polymerization properties throughout 33 days.

Figure 1

FIBTEM-A10 was strongly correlated with fibrinogen level. The FIBTEM-A10 test is commonly used for the clinical assessment of plasma fibrinogen level.

Figure 2

FIBTEM-A20 was strongly correlated with fibrinogen level.

Figure 3

FIBTEM-MCF was strongly correlated with fibrinogen level. This close association indicates that the quantity and fibrin polymerization properties of autologous whole blood were retained for up to 33 days in cold storage. MCF = maximum clot firmness.

Figure 4

INTEM-MCF was moderately correlated with FIBTEM-MCF. MCF = maximum clot firmness.

Figure 5

EXTEM-MCF was moderately correlated with FIBTEM-MCF. The MCF values of EXTEM and FIBTEM were very similar. The result could be explained by the deficiency in the platelet count. MCF = maximum clot firmness.

Figure 6

We observed a moderate correlation between storage duration and INTEM clotting time. CT = clotting time.

Figure 7

We observed a weak correlation between EXTEM clotting time in and storage duration. This may indicate that the level of extrinsic coagulation factors decreases with increasing cold storage duration. CT = clotting time.

Figure 8

Storage duration was not correlated with fibrinogen level.