Abstract
Blood pressure (BP) control is urgent for the management of patients with acute hypertensive cerebral hemorrhage (AHCH). However, there is little information concerning how far BP can be safely reduced in patients with AHCH. The authors provided following hemodynamic investigation to clarify the lower limit of BP in the treatment of AHCH.
Thirteen patients with supratentorial AHCH, whose habitual BP before ictus was known, were subjected in this study. In all cases, size of hematoma was medium, as estimated by CT scans. During acute stage, BP was gradually reduced by intravenous administration of trimetaphan camsilate combined with head-up tilting. The rate of cerebral blood flow (CBF) changes were repeatedly measured by the arteriovenous oxygen difference method. Blood pressure was measured with transducers. Lower limit of BP was estimated from BP-CBF relationship curves, and relationships between lower limit and habitual mean arterial BP (habitual BP) as well as post-ictal BP before treatment was investigated. In two cases, BP-CBF relationship were tested in both acute and chronic stage.
The results were summerized as follows :
1) Autoregulatory response was maintained to a certain extent in the majority of cases.
2) Lower limit of autoregulation was almost equal to pre-ictal habitual BP.
3) Lower limit of autoregulation varied in each case, however, it existed almost always at the level corresponding to 80% of post-ictal BP measured before treatment.
4) In one case, lower limit of autoregulation was slightly higher than habitual BP in acute stage of ictus. However, in chronic stage, the lower limit was lowered below habitual BP. The other case, dysautoregulation pattern was seen in acute stage of ictus, but autoregulatory range was appeared in chronic stage.
The present study suggested that 20% reduction of post-ictal BP was considered to be maximum during acute stage, but not below habitual BP level.
