Cerebral vascular reactivity response to anaesthetic induction with propofol in patients with intracranial space-occupying lesions and vascular malformations.
OBJECTIVE
In clinical trials, autoregulation and carbon dioxide reactivity are preserved during propofol anaesthesia. Paradoxical increases of blood flow velocity during induction of anaesthesia could be demonstrated in patients with brain tumours. This study evaluates the effects of propofol on cerebral blood flow velocity in patients undergoing surgery for brain tumours and vascular malformations.


METHODS
Changes in cerebral blood flow velocity after the administration of propofol were assessed using bilateral 2 MHz transcranial Doppler probes in 47 patients undergoing surgery for brain tumours and in 22 patients undergoing surgery for aneurysms and angiomas.


RESULTS
Flow reduction after propofol was slightly less pronounced on the side of the tumour; in patients with cerebrovascular lesions, no difference between the two sides was detectable. After the administration of propofol a flow increase was present on the side of the tumour in 2 patients. In 3 patients with angiomas, the flow decrease after the administration of propofol was less pronounced on the side of the angioma. Neither observation gave statistical proof of abnormality.


CONCLUSIONS
The flow changes after propofol may give a hint of cerebrovascular reactivity. Further investigations should focus on combined measurements of cerebral autoregulation and carbon dioxide reactivity and should focus on patients with impaired consciousness to test for reliability.
Schmieder
K
K
Ruhr-University Bochum, Department of Neurosurgery, Bochum, Germany. kirsten.schmieder@ruhr-uni-bochum.de
Schregel
W
W
Engelhardt
M
M
Harders
A
A
Cunitz
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D001932:Brain Neoplasms / Q000503:physiopathology*; D020785:Central Nervous System Vascular Malformations / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D006391:Hemangioma / Q000503:physiopathology*; D006801:Humans; D002532:Intracranial Aneurysm / Q000503:physiopathology; D008875:Middle Aged; D015742:Propofol / Q000494:pharmacology*
D018686:Anesthetics, Intravenous; D015742:Propofol