Changes of cerebral blood flow pre-and post-treatment with mannitol in patients with acute stroke

Objective To find out the relationship between the use of different dosages of mannitol and the changes of cerebral blood flow in patients with stroke at the peak of edema formation.Methods Twenty- eight patients with hemispheric stroke were treated with 20％mannitol solution for reduction of increased intracranial pressure,at the dosages of 125 ml or 250 ml.Transcranial Doppler was used to monitor the blood flow of the bilateral middle cerebral arteries before and after the treatment.The monitoring parameters included peak systolic velocity(Vs),end diastolic velocity(Vd),mean velocity(Vm),and pulsatility index(PI),and percentage rate(PR)of change in each parameter.At the same time,the blood pressure of brachial artery was monitored.Results Vs,Vd,and Vm on the affected and unaffected sides were improved significantly in patients using 125 ml mannitol.The PI on the affected sides decreased markedly (P=0.002,P=0.028)from 45 min to 60 min;the PI on the unaffected sides did not decrease significant- ly(P＞0.05);there were no significant differences in the PR of Vs,Vd,Vm and PI on both sides(P＞0.05).Vs,Vd,and Vm on the affected and unaffected sides were improved fluetuatly in patients using 250 ml mannitoh The PI on the affected sides did not decrease markedly(P＞0.05);the PI on the unaffected sides decreased significantly(P=0.005)60 rain after mannitol infusion;the PR of PI at 60 min had signif- icant difference between two sides(P=0.006).The peaks of the velocity of blood flow increasing and PI decreasing on the affected sides occured later than that on the unaffected sides in patients both using 125 ml and 250 ml mannitol.Conclusion The improvement of cerebral hemodynamics on the affected sides is more significant than that on the unaffected sides with 125 ml mannitol,and the improvement of cerebral he- modynamics on the unaffected sides is more significant than that on the affected sides with 250 ml mannitol.