Mechanisms of platelet dysfunction in patients with gastroduodenal ulcer bleeding
Platelet reactivity was estimated in 247 patients with gastric and duodenal ulcer bleeding. Platelet aggregation was measured using aggregometry with adenosine diphosphate (5 mkM), epinephrine (2.5 mkM), 5-hydroxytryptamine (10 mkM), collagen (1 mkM) and thrombin (0.05 NIH/ml). The relationship between platelet aggregation and spatial-temporal characteristics of ulcers complicated by bleeding were shown. Adrenoreactivity of platelets was associated with terms after beginning of ulcer bleeding and hemorrhage degree. The lowest platelet response to collagen and thrombin was detected in patients with active bleeding (p<0.001) and unsustainable hemostasis (p<0.01). Additionally to gender factor, the important determinant of unsustainable hemostasis was decrease of platelet response to thrombin and adenosine diphosphate.