Cerebral Blood Flow, Cerebral Metabolism and Cerebrospinal Fluid Biochemistry in Brain-Injured Patients after Exposure to Hyperbaric Oxygen

1976 ◽  
Vol 14 (5) ◽  
pp. 351-364 ◽  
Author(s):  
François Artru ◽  
Bernard Philippon ◽  
Françoise Gau ◽  
Michel Berger ◽  
Raymond Deleuze
2001 ◽  
Vol 94 (3) ◽  
pp. 403-411 ◽  
Author(s):  
Sarah B. Rockswold ◽  
Gaylan L. Rockswold ◽  
Janet M. Vargo ◽  
Carla A. Erickson ◽  
Richard L. Sutton ◽  
...  

Object. Hyperbaric oxygenation (HBO) therapy has been shown to reduce mortality by 50% in a prospective randomized trial of severely brain injured patients conducted at the authors' institution. The purpose of the present study was to determine the effects of HBO on cerebral blood flow (CBF), cerebral metabolism, and intracranial pressure (ICP), and to determine the optimal HBO treatment paradigm. Methods. Oxygen (100% O2, 1.5 atm absolute) was delivered to 37 patients in a hyperbaric chamber for 60 minutes every 24 hours (maximum of seven treatments/patient). Cerebral blood flow, arteriovenous oxygen difference (AVDO2), cerebral metabolic rate of oxygen (CMRO2), ventricular cerebrospinal fluid (CSF) lactate, and ICP values were obtained 1 hour before and 1 hour and 6 hours after a session in an HBO chamber. Patients were assigned to one of three categories according to whether they had reduced, normal, or raised CBF before HBO. In patients in whom CBF levels were reduced before HBO sessions, both CBF and CMRO2 levels were raised 1 hour and 6 hours after HBO (p < 0.05). In patients in whom CBF levels were normal before HBO sessions, both CBF and CMRO2 levels were increased at 1 hour (p < 0.05), but were decreased by 6 hours after HBO. Cerebral blood flow was reduced 1 hour and 6 hours after HBO (p < 0.05), but CMRO2 was unchanged in patients who had exhibited a raised CBF before an HBO session. In all patients AVDO2 remained constant both before and after HBO. Levels of CSF lactate were consistently decreased 1 hour and 6 hours after HBO, regardless of the patient's CBF category before undergoing HBO (p < 0.05). Intracranial pressure values higher than 15 mm Hg before HBO were decreased 1 hour and 6 hours after HBO (p < 0.05). The effects of each HBO treatment did not last until the next session in the hyperbaric chamber. Conclusions. The increased CMRO2 and decreased CSF lactate levels after treatment indicate that HBO may improve aerobic metabolism in severely brain injured patients. This is the first study to demonstrate a prolonged effect of HBO treatment on CBF and cerebral metabolism. On the basis of their data the authors assert that shorter, more frequent exposure to HBO may optimize treatment.


1989 ◽  
Vol 257 (4) ◽  
pp. H1220-H1227 ◽  
Author(s):  
H. Schrock ◽  
W. Kuschinsky

Chronic metabolic alkalosis was induced in rats by combining a low K+ diet with a 0.2 M NaHCO3 solution as drinking fluid for either 15 or 27 days. Local cerebral blood flow and local cerebral glucose utilization were measured in 31 different structures of the brain in conscious animals by means of the iodo-[14C]antipyrine and 2-[14C]deoxy-D-glucose method. The treatment induced moderate [15 days, base excess (BE) 16 mM] to severe (27 days, BE 25 mM) hypochloremic metabolic alkalosis and K+ depletion. During moderate metabolic alkalosis no change in cerebral glucose utilization and blood flow was detectable in most brain structures when compared with controls. Cerebrospinal fluid (CSF) K+ and H+ concentrations were significantly decreased. During severe hypochloremic alkalosis, cerebral blood flow was decreased by 19% and cerebral glucose utilization by 24% when compared with the control values. The decrease in cerebral blood flow during severe metabolic alkalosis is attributed mainly to the decreased cerebral metabolism and to a lesser extent to a further decrease of the CSF H+ concentration. CSF K+ concentration was not further decreased. The results show an unaltered cerebral blood flow and glucose utilization together with a decrease in CSF H+ and K+ concentrations at moderate metabolic alkalosis and a decrease in cerebral blood flow and glucose utilization together with a further decreased CSF H+ concentration at severe metabolic alkalosis.


1959 ◽  
Vol 197 (4) ◽  
pp. 825-828 ◽  
Author(s):  
Edgar A. Bering

The cerebrospinal fluid production has been studied in the dog under conditions of maximum obtainable flow rates from the cisterna magna. Under these conditions the fluid had constant composition and was assumed to represent the cerebrospinal fluid in the intact state. Cerebral blood flow and cerebral oxygen consumption were measured by the method of Kety and Schmidt. The only significant correlations found were with oxygen consumption when the CSF flow rate was in terms of brain weight and with cerebral blood flow and cerebral vascular resistance when CSF flow was in terms of choroid plexus weight. A combined regression equation was calculated which satisfactorily accounted for the observed CSF flow: CSF cu mm/min. = .128 x CMRO2 x brain wgt. + 0.15 x CVR x choroid plexus wt. This suggested separate physiological processes, one correlated with oxygen metabolism and one with hydrodynamic factors of the cerebral blood flow. The data demonstrated that the choroid plexus alone could not have accounted for the entire CSF flow and some must have come from another source, presumably the brain.


1975 ◽  
Vol 49 (2) ◽  
pp. 157-169
Author(s):  
N. N. Stanley ◽  
B. G. Salisbury ◽  
L. C. McHenry ◽  
N. S. Cherniack

1. The acid-base state of arterial blood and cerebrospinal fluid, and the ventilatory response to CO2, were measured in twelve patients with liver disease. The CO2 response was also measured in eight goats before and after the experimental production of liver failure. Arterial Pco2 and pH, cerebral blood flow and the cerebral metabolic rate for oxygen were also measured in four of the goats while they breathed air and various CO2-enriched gas mixtures. 2. Liver failure was accompanied by a respiratory alkalosis in both the patients and in the goats. Decreased Pco2 and increased pH occurred in the cerebrospinal fluid and in the arterial blood of the patients. 3. The slope of the ventilatory response to CO2 was reduced when liver failure was severe, in patients and goats alike. In addition there was a reduction in the extrapolated Pco2 at zero ventilation, even when liver failure was mild. 4. Cerebral blood flow and metabolic rate were consistently reduced in the goats during liver failure. There was also less cerebral vasodilatation and a greater reduction in cerebral metabolism during experimental hypercapnia when these animals were in liver failure. 5. The decreases in the ventilatory and cerebral circulatory responsiveness to CO2 indicate that the brain is less well defended against hypercapnia in liver failure, and these changes are especially unfavourable as cerebral function deteriorates when the Pco2 is increased.


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