SYSTEMIC BLOOD ACTIVATION DURING AND AFTER AUTOTRANSFUSION

To evaluate the extent of shed blood activation in two autotransfusion systems and the effect of circulating blood activation upon autotrans fusion, we performed a prospective study in 18 patients undergoing int ernal mammary artery bypass operation and a control group of 10 patien ts. The autotransfusion systems were from Sorin (n = 9) consisting of a hard shell reservoir with a filter having a small contact area (0.32 m(2)), and from Dideco (n = 9) consisting of a hard shell reservoir w ith a filter having a larger contact area (4.64 m(2)). We found high c oncentrations of thromboxane, fibrinogen degradation products, complem ent split product C3a, and elastase in the shed blood and, with the ex ception of C3a, in the circulating blood of autotransfused patients. T here was no such activation in control patients. The degree of the sys temic inflammatory reaction was determined by the type of autotransfus ion system and by the amount of infused shed blood. The Dideco system provoked more inflammatory response than did the Sorin. This was refle cted by the larger shed blood loss during autotransfusion in the Didec o patients than in Sorin patients, resulting in infusion of more shed blood (means, 737 mL versus 566 mL; not significant). After autotransf usion, Dideco patients shed significantly more blood than did Sorin or control patients (p < 0.05). Dideco patients also needed more colloid /crystalloid solution per 24 hours than Sorin patients (p < 0.05). Thi s became clinically relevant only after infusion of more than 800 mL o f shed blood (p < 0.001): hemodilution indicated the need for packed c ells in 4 Dideco patients and in 1 Sorin patient. Dideco patients requ ired a similar amount of blood products (0.8 +/- 0.4 unit) to the cont rol patients. In contrast, Sorin patients required a mean of 0.2 +/- 0 .2 unit, whereas blood products were avoided in 89% of them, versus 42 % of the Dideco and control patients (not significant). In summary, we recommend autotransfusion of a limited amount (less than 800 mL) of s hed blood with a reservoir that has the smallest possible contact area . Infusion of more than 800 mL of shed blood provokes derangement of h emostasis and hemodynamics by deleterious systemic blood activation, n ullifying blood saving by autotransfusion.