title: Autoregulation of cerebral blood flow surrounding acute (6 to 22 hours) intracerebral hemorrhage.
abstract: BACKGROUND
  Arterial hypertension is common in the first 24 hours after acute intracerebral hemorrhage (ICH). Although increased blood pressure usually declines to baseline values within several days, the appropriate treatment during the acute period has remained controversial. Arguments against treatment of hypertension in patients with acute ICH are based primarily on the concern that reducing arterial blood pressure will reduce cerebral blood flow (CBF). The authors undertook this study to provide further information on the changes in whole-brain and periclot regional CBF that occur with pharmacologic reductions in mean arterial pressure (MAP) in patients with acute ICH.
  
  
  METHODS
  Fourteen patients with acute supratentorial ICH 1 to 45 mL in size were studied 6 to 22 hours after onset. CBF was measured with PET and (15)O-water. After completion of the first CBF measurement, patients were randomized to receive either nicardipine or labetalol to reduce MAP by 15%, and the CBF study was repeated.
  
  
  RESULTS
  MAP was lowered by -16.7 +/- 5.4% from 143 +/- 10 to 119 +/- 11 mm Hg. There was no significant change in either global CBF or periclot CBF. Calculation of the 95% CI demonstrated that there is less than a 5% chance that global or periclot CBF fell by more than -2.7 mL x 100 g(-1) x min(-1).
  
  
  CONCLUSIONS
  In patients with small- to medium-sized acute ICH, autoregulation of CBF was preserved with arterial blood pressure reductions in the range studied.
authors.affiliation: Department of Neurology and Neurological Surgery, Lillian Strauss Institute for Neuroscience, Washington University School of Medicine, St. Louis, MO 631101, USA. wjp@npg.wustl.edu
authors.forename: W J
authors.initials: WJ
authors.lastname: Powers
authors.forename: A R
authors.initials: AR
authors.lastname: Zazulia
authors.forename: T O
authors.initials: TO
authors.lastname: Videen
authors.forename: R E
authors.initials: RE
authors.lastname: Adams
authors.forename: K D
authors.initials: KD
authors.lastname: Yundt
authors.forename: V
authors.initials: V
authors.lastname: Aiyagari
authors.forename: R L
authors.initials: RL
authors.lastname: Grubb
authors.forename: M N
authors.initials: MN
authors.lastname: Diringer
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005260:Female; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D007741:Labetalol / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009529:Nicardipine / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed
chemical_list: D000959:Antihypertensive Agents; D009529:Nicardipine; D007741:Labetalol