[Conditions of artificial blood circulation and erythrocytic aggregation in cardiosurgical patients].

Normothermic artificial circulation, irrespective of its duration, enhances erythrocyte aggregation in response to noradrenaline stimulation. Short-term hypothermic perfusion reduces adrenergic aggregation of erythrocytes while in long-term hypothermic artificial circulation changes in erythrocyte adrenergic aggregation are not significant. In the course of cardiosurgical operation in conditions of artificial circulation adrenergic erythrocyte aggregation undergoes changes: a maximal rise before perfusion, linear lowering and rise to the preoperative level. If perfusion lasts longer than 90 min adrenergic aggregation of erythrocytes sharply and significantly falls. This aggregation depends little on hematocrit, but if it falls under 15% aggregation becomes significant which may be of importance in blood loss arrest in massive blood loss, hemodilution, dilution of coagulation factors and marked thrombocytopenia. In such conditions erythrocyte aggregates may seal damaged microvessels acting as hemostatic lock.