Hematocrit, Blood Viscosity and Plasma Viscosity in Patients with Aneurysmal Subarachnoid Hemorrhage

Choi, Ki Suk; Yim, Man Bin; Son, Eun Ik; Kim, Dong Won; Kim, In Hong; Jeon, Dong Seok

Abstract

In order to find out the relationship between blood viscosity and the development of an ischemic symptom(clinical vasospasm) following an aneurysmal subarachnoid hemorrhage(SAH), was checked daily the hematocrit(Hct), blood viscosity and plasma viscosity from admission day to 14 days after SAH in 33 patients. Twelve patients with diseases except those with a SAH were selected as a control group. We analyzed the difference of the average hematocrit, blood viscosity, and plasma viscosity between the control group, non-spasm group and spasm group on admission, and then the period of preoperative, postoperative with mannitolization, and postoperative without mannitolization. We also analyzed the change of those according to the SAH day, and the relationship between the blood viscosity and the level of hematocrit in each group. As a result, aneurysmal SAH patients with clinical vasospasm showed a higher plasma viscosity than the control(1.82+/-0.21 vs. 1.55+/-0.14, respectively : p<0.01) and clinical non-spasm(1.82+/-0.21 vs. 1.66+/-0.12, respectively : p<0.05) group of patients on admission statistically. In the spasm group, the blood viscosity was raised during the spasm risk period(SAH 7-10 days). The level of the hematocrit in the spasm group was lower than the non-spasm group and most of them checked below 30% after surgery. In the relationship between the level of hematocrit and the blood viscosity, the spasm group showed a relatively higher blood viscosity than the non-spasm group. These results suggest that the blood viscosity has some role in the development of ischemic symptoms after a subarachnoid hemorrhage, but major determinants such as erythrocyte aggregation, plasma fibrinogen concentration and platelet aggregation which affect the microcirculation have a more important role. Therefore, when hemodilution are used for prevention or improvement of ischemic symptoms after subarachnoid hemorrhage, the level of the hematocrit and the focus on decreasing the major determinants of the viscosity in microcirculation should be considered.