title: The effect of isoflurane on cerebral blood flow and metabolism in humans during craniotomy for small supratentorial cerebral tumors.
abstract: Fourteen patients were studied during craniotomy for small supratentorial cerebral tumors. Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) were measured twice by a modification of the Kety-Schmidt technique using 133Xe intravenously. Anesthesia was induced with thiopental 5-7 mg X kg-1, fentanyl 0.2 mg, and pancuronium, and maintained with 0.75% inspired isoflurane concentration in 67% nitrous oxide, and moderate hypocapnia. In one group of patients (n = 7), the inspired isoflurane concentration was maintained at 0.75% throughout anesthesia. One hour after induction of anesthesia, CBF and CMRO2 averaged 31 +/- 3 ml X 100 g-1 X min-1 and 2.1 +/- 0.2 ml O2 X 100 g-1 X min-1 (X +/- SEM), respectively. During repeat studies 1 h later, CBF and CMRO2 were unchanged. In a second group of patients (n = 7), an increase in the inspired isoflurane concentration from 0.75% to 1.5% was associated with a significant decrease in CMRO2 from 2.4 +/- 0.1 to 1.9 +/- 0.1 ml O2 X 100 g-1 X min-1, and no change in CBF. It is concluded that this anesthetic regimen is safe to use in patients with small supratentorial tumors in whom only a small midline shift has occurred.
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D001921:Brain / Q000378:metabolism*; D001932:Brain Neoplasms / Q000601:surgery*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D003399:Craniotomy; D005625:Frontal Lobe; D006801:Humans; D007530:Isoflurane; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects; D010296:Parietal Lobe
chemical_list: D007530:Isoflurane