Regional cerebral blood flow, blood volume, oxygen extraction fraction, and oxygen utilization rate in normal volunteers measured by the autoradiographic technique and the single breath inhalation method

1995 ◽  
Vol 9 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Jun Hatazawa ◽  
Hideaki Fujita ◽  
Iwao Kanno ◽  
Takao Satoh ◽  
Hidehiro Iida ◽  
...  
Keyword(s):  
Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Oxygen Extraction Fraction ◽  
Utilization Rate ◽  
Regional Cerebral Blood ◽  
Oxygen Utilization ◽  
Single Breath ◽  
Extraction Fraction ◽  
Autoradiographic Technique ◽  
Oxygen Utilization Rate

Effects of Sevoflurane, Propofol, and Adjunct Nitrous Oxide on Regional Cerebral Blood Flow, Oxygen Consumption, and Blood Volume in Humans

2003 ◽  
Vol 99 (3) ◽  
pp. 603-613 ◽  
Author(s):  
Kaike K. Kaisti ◽  
Jaakko W. Långsjö ◽  
Sargo Aalto ◽  
Vesa Oikonen ◽  
Hannu Sipilä ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Nitrous Oxide ◽  
Regional Cerebral Blood Flow ◽  
Emission Tomography ◽  
Oxygen Extraction Fraction ◽  
Regional Cerebral Blood ◽  
Extraction Fraction ◽  
Positron Emission ◽  
End Tidal

Background Anesthetic agents, especially volatile anesthetics and nitrous oxide (N2O), are suspected to perturb cerebral homeostasis and vascular reactivity. The authors quantified the effects of sevoflurane and propofol as sole anesthetics and in combination with N2O on regional cerebral blood flow (rCBF), metabolic rate of oxygen (rCMRO2), and blood volume (rCBV) in the living human brain using positron emission tomography. Methods 15O-labeled water, oxygen, and carbon monoxide were used as positron emission tomography tracers to determine rCBF, rCMRO2 and rCBV, respectively, in eight healthy male subjects during the awake state (baseline) and at four different anesthetic regimens: (1) sevoflurane alone, (2) sevoflurane plus 70% N2O (S+N), (3) propofol alone, and (4) propofol plus 70% N2O (P+N). Sevoflurane and propofol were titrated to keep a constant hypnotic depth (Bispectral Index 40) throughout anesthesia. End-tidal carbon dioxide was strictly kept at preinduction level. Results The mean +/- SD end-tidal concentration of sevoflurane was 1.5 +/- 0.3% during sevoflurane alone and 1.2 +/- 0.3% during S+N (P < 0.001). The measured propofol concentration was 3.7 +/- 0.7 microg/ml during propofol alone and 3.5 +/- 0.7 microg/ml during P+N (not significant). Sevoflurane alone decreased rCBF in some (to 73-80% of baseline, P < 0.01), and propofol in all brain structures (to 53-70%, P < 0.001). Only propofol reduced also rCBV (in the cortex and cerebellum to 83-86% of baseline, P < 0.05). Both sevoflurane and propofol similarly reduced rCMRO2 in all brain areas to 56-70% and 50-68% of baseline, respectively (P < 0.05). The adjunct N2O counteracted some of the rCMRO2 and rCBF reductions caused by drugs alone, and especially during S+N, a widespread reduction (P < 0.05 for all cortex and cerebellum vs. awake) in the oxygen extraction fraction was seen. Adding of N2O did not alter the rCBV effects of sevoflurane and propofol alone. Conclusions Propofol reduced rCBF and rCMRO2 comparably. Sevoflurane reduced rCBF less than propofol but rCMRO2 to an extent similar to propofol. These reductions in flow and metabolism were partly attenuated by adjunct N2O. S+N especially reduced the oxygen extraction fraction, suggesting disturbed flow-activity coupling in humans at a moderate depth of anesthesia.

Regional cerebral blood flow and oxygen utilization in superficial temporal-middle cerebral artery anastomosis patients

1979 ◽  
Vol 50 (6) ◽  
pp. 733-741 ◽  
Author(s):  
Robert L. Grubb ◽  
Robert A. Ratcheson ◽  
Marcus E. Raichle ◽  
Arthur B. Kliefoth ◽  
Mokhtar H. Gado
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Regional Cerebral Blood Flow ◽  
Superficial Temporal Artery ◽  
Regional Cerebral Blood ◽  
Oxygen Utilization ◽  
Cerebrovascular Lesions ◽  
Before And After

✓ Regional cerebral blood flow (rCBF) and regional cerebral oxygen utilization (rCMRO2) were measured before and after surgery in nine patients undergoing a superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis to bypass cerebrovascular lesions not amenable to extracranial operative procedures. The objective of these studies was to determine whether measurements of this type could provide objective criteria for surgery as well as assess the effect of surgery. The preliminary data, although limited, suggest that measurements of regional cerebral hemodynamics and metabolism in these patients before and after surgery provide valuable data upon which to develop criteria and assess results. For example, 1) a significant depression of rCBF and rCMRO2 in patients in whom a major cerebral infarction has not occurred, or 2) relative preservation of rCMRO2 despite depressed rCBF seem to be favorable indications for establishing a functioning STA-MCA anastomosis. In such patients, STA-MCA anastomosis can be followed by a return of rCBF and rCMRO2 to virtually normal levels. Relatively normal rCBF and rCMRO2 in the presence of an occluded internal carotid artery in asymptomatic patients indicates satisfactory collateral circulation and is probably a contraindication to surgery.

Study of Regional Cerebral Blood Flow and Oxygen Utilization with Positron Emission Tomography and 15O

1980 ◽  
Vol 58 (2) ◽  
pp. 8P-8P
Author(s):  
R. S. J. Frackowiak ◽  
G. L. Lenzi ◽  
T. Jones ◽  
J. Heather ◽  
P. D. Buckingham ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Emission Tomography ◽  
Regional Cerebral Blood ◽  
Oxygen Utilization ◽  
Positron Emission

Effects of Subanesthetic Doses of Ketamine on Regional Cerebral Blood Flow, Oxygen Consumption, and Blood Volume in Humans

2003 ◽  
Vol 99 (3) ◽  
pp. 614-623 ◽  
Author(s):  
Jaakko W. Långsjö ◽  
Kaike K. Kaisti ◽  
Sargo Aalto ◽  
Susanna Hinkka ◽  
Riku Aantaa ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Frontal Cortex ◽  
Blood Volume ◽  
Regional Cerebral Blood Flow ◽  
Region Of Interest ◽  
Anterior Cingulate ◽  
Oxygen Extraction Fraction ◽  
Dependent Manner ◽  
Regional Cerebral Blood

Background Animal experiments have demonstrated neuroprotection by ketamine. However, because of its propensity to increase cerebral blood flow, metabolism, and intracranial pressure, its use in neurosurgery or trauma patients has been questioned. Methods 15O-labeled water, oxygen, and carbon monoxide were used as positron emission tomography tracers to determine quantitative regional cerebral blood flow (rCBF), metabolic rate of oxygen (rCMRO2), and blood volume (rCBV), respectively, on selected regions of interest of nine healthy male volunteers at baseline and during three escalating concentrations of ketamine (targeted to 30, 100, and 300 ng/ml). In addition, voxel-based analysis for relative changes in rCBF and rCMRO2 was performed using statistical parametric mapping. Results The mean +/- SD measured ketamine serum concentrations were 37 +/- 8, 132 +/- 19, and 411 +/- 71 ng/ml. Mean arterial pressure was slightly elevated (maximally by 15.3%, P < 0.001) during ketamine infusion. Ketamine increased rCBF in a concentration-dependent manner. In the region-of-interest analysis, the greatest absolute changes were detected at the highest ketamine concentration level in the anterior cingulate (38.2% increase from baseline, P < 0.001), thalamus (28.5%, P < 0.001), putamen (26.8%, P < 0.001), and frontal cortex (25.4%, P < 0.001). Voxel-based analysis revealed marked relative rCBF increases in the anterior cingulate, frontal cortex, and insula. Although absolute rCMRO2 was not changed in the region-of-interest analysis, subtle relative increases in the frontal, parietal, and occipital cortices and decreases predominantly in the cerebellum were detected in the voxel-based analysis. rCBV increased only in the frontal cortex (4%, P = 0.022). Conclusions Subanesthetic doses of ketamine induced a global increase in rCBF but no changes in rCMRO2. Consequently, the regional oxygen extraction fraction was decreased. Disturbed coupling of cerebral blood flow and metabolism is, however, considered unlikely because ketamine has been previously shown to increase cerebral glucose metabolism. Only a minor increase in rCBV was detected. Interestingly, the most profound changes in rCBF were observed in structures related to pain processing.

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