[On the mechanism of action of recombinant activated factor VII in massive non-hemophylic bleeding in cardiosurgical patients].
Recombinant activated factor VII was used in a dose of 30 to 140 mcgr/kg in 35 cardiosurgical patients during intra- and postoperative periods complicated by massive uncontrolled (5 to 25 ml/min) bleeding of non-surgical origin. Basing on the analysis of changes in the hemostasis system parameters, the mechanism of action of the preparation may be presented as follows: recombinant fVIIa forms a complex with TF at the site of lesion; the formation of TF-fVIIa complex leads to the appearance of small amount of synthesized thrombin on the membrane of TF-containing cells, which, in turn, activates thrombocytes at the site of lesion; thrombocytes excrete phosphatidylserine, which serves as a matrix for further thrombin formation. FXIII is expressed from a granules ofthrombocytes and gets activated. FXIII binds with a specific receptor on platelets' membrane. It remains active as enzyme and participates in the formation of a firm fibrin plug at the site of lesion. Besides, substances with pro- and antifibrinolytic activity, antiheparin factor 4 and fibronectin are released from alpha granules. Factors IXa, VIIIa, and Va effectively "attach" to the surface of activated thrombocytes, and the forming of IXa-VIIIa complex leads to further activation of factor X, which, together with factor 3 expression, facilitates further local thrombin generation.
Dement'eva
I I
II
Gladysheva
V G
VG
Charnaia
M A
MA
Morozov
Iu A
IuA
D016063:Blood Loss, Surgical / Q000517:prevention & control*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015942:Factor VIIa / Q000008:administration & dosage / Q000627:therapeutic use*; D005176:Factor XIII / Q000378:metabolism; D005500:Follow-Up Studies; D006487:Hemostasis / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D007430:Intraoperative Care / Q000379:methods*; D010314:Partial Thromboplastin Time; D011182:Postoperative Care / Q000379:methods*; D019106:Postoperative Hemorrhage / Q000097:blood / Q000188:drug therapy*; D013925:Thromboplastin / Q000378:metabolism; D016896:Treatment Outcome