Introduction. Rupture of cerebral aneurysms (CA) with the development of intracranial hemorrhage (ICH), complicated in some cases by vascular spasm and delayed cerebral ischemia (DCI), is due to the complex multifactorial genesis of the disease, including changes in the blood oxygen transport function (BOTF), activation of endothelial cells with a release of vasoregulators, reactive oxygen species, inflammatory proteins, as well as disturbances in the hemostasis system.Purpose – to study the indicators of BOTF, primary and secondary hemostasis and the content of some vasoregulatory metabolites in the pre- and postoperative periods in patients with ruptured CA with the development of DCI and without DCI.Materials and methods. The group with DCI included 45 patients; in the group without DCI were 14 people. Clinical-neurological and neuroimaging examinations were carried out, and parameters of BOTF, primary and secondary hemostasis, nitrate/nitrite, angiotensin-converting enzyme (ACE), and PAI-1 concentrations in venous blood were studied before and on days 10–12 after microsurgical clipping of the CA.Results. We diagnosed mild neurological disorders according to the NIHSS scale, confirmed by neuroimaging studies of the brain in the group of DCI patients. It was shown an increase in thrombin-dependent platelet aggregation velocity to 30.6 (24.3; 32.4) AU/min at norm 21.8 (20.3; 24.9) (U, p=0.009) before surgery; and after surgery it was up to 37.4 (30; 44.7) relative to the norm (U, p=0.001). Before surgery, the following was observed: PT shortening to 11.6±0.7 sec at norm 13.2±1.1 (t, p˂0.001), fibrinogen concentration increasing to 4.35 (3.8; 4.8) g/L at norm 3.9 (3.6; 4.1) g/L (U, p = 0.01) and PAI-1 up to 3.9 (2.6; 4.8) ng / mL at norm 2 .7 (2.2; 4.1). After surgery, PT was 11.9±1.1 (t, p˂0.001); fibrinogen - 4.4 (3.9; 4.8) (U, p=0.024), PAI-1 - 4.6 (4.1; 6.7) (U, p=0.0004) respectively. Before surgery, p50 was increased to 28.1 (26.2; 31.6) mm Hg at norm 25.2 (24.3; 26.8) (U, p=0.025); after surgery, it was up to 28.5 (26.8; 30.7) (U, p=0.03) and the ratio of nitrates/nitrites to ACE was reduced to 0.12 (0.08; 0.15) at norm 0.22 (0.15; 0.32) (U, p˂0.001); after - up to 0.11 (0.08; 0.19) (U, p˂0.001) respectively.Conclusion. There has been revealed significant disorders of primary and secondary hemostasis with fibrinolysis inhibition, a decrease in the affinity of hemoglobin to oxygen at the p50 rate and an imbalance of the content of vasoregulatory metabolites in patients with DCI before and after aneurysm clipping, which can be considered as significant factors in the development of DCI after aneurysmal ICH.
