title: The effects of sodium nitroprusside on cerebral blood flow and cerebral venous blood gases. I. Observations in awake man during and following moderate blood pressure reduction.
abstract: Cerebral blood flow (CBF) and cerebral venous blood gases were studied in seven patients before, during and after intravenous sodium nitroprusside infusion. The 133Xe intra-arterial injection method was used for the CBF measurements. A dose of sodium nitroprusside (mean 1.0 mg, mean infusion time 20 min), which reduced mean arterial blood pressure by a mean of 17%, resulted in a 13% decrease in CBF (P less than 0.05). Measurements obtained 5 and 20 min after termination of the sodium nitroprusside infusion showed no signs of a hyperaemic rebound effect. Arterial PCO2, metabolic rate of oxygen, arterio-venous oxygen difference and venous PO2 remained unchanged during and after infusion. It is concluded that sodium nitroprusside has a minor effect on cerebral haemodynamics, an effect that might be mediated by the sympathetic nervous system.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005260:Female; D005292:Ferricyanides / Q000494:pharmacology*; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D007022:Hypotension / Q000139:chemically induced* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009599:Nitroprusside / Q000008:administration & dosage / Q000494:pharmacology*; D010100:Oxygen / Q000097:blood
chemical_list: D005292:Ferricyanides; D002245:Carbon Dioxide; D009599:Nitroprusside; D010100:Oxygen