EFFECTS OF 0.08 and 0.8 ATMOSPHERES OF INSPIRED pO2 UPON CEREBRAL HEMODYNAMICS AT A ???CONSTANT??? ALVEOLAR pCO2 OF 43 mm. Hg

Turner, J. A.; Lambertsen, CJ; Owen, S. G.; Wendel, HP; Chiodi, Hugo

doi:10.1097/00132586-195710000-00043

Cited by 10 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Turner el al. [35] have shown in human subjects that, when arterial Pco is maintained at a constant level during oxygen inhalation, no reduction in cerebral blood flow takes place, indicating that the vasoconstrictive effect is an indirect one resulting from a lowered blood P c0 .,-Their findings, however, are not in agreement with those of Jacobscn el al. [M], who, in studies in the adult dog, also maintained alveolar P c0 ., constant, yet found a 15% reduction in cerebral blood flow during 100% oxygen inhalation.…”

Section: Effects Of Chronic Oxygen Exposurementioning

confidence: 76%

“…The mechanism of the vasoconstrictive action is not known and has been attributed to a direct elfect of oxygen on vessel walls [29]. Evidence has been presented, however, to indicate that part, if not all, of the action is secondary to hyperventilation and hypocapnia which accompany oxygen inhalation [35]. A slightly more intense but qualitatively similar action of ambient hyperoxia has been observed in retinal vessels [7,8,30], and, during early maturation, when retinal vasculature is in a state of formation, the constrictive effect o£ 660 KENNEDY, GRAVE, AND JEHLE oxygen inhalation is even more pronounced [3,26].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Hyperoxia on the Cerebral Ciculation of the Newborn Puppy

Kennedy¹,

Grave²,

Jehle³

1971

Pediatr Res

View full text Add to dashboard Cite

ExtractLocal cerebral blood flow (CBF) in the 2-day-old puppy ranged between 0.58 (superior olive) and 0.07 ml/g/min (centrum ovale), with average values in gray matter of the cerebral cortex, deep cerebral structures, and brain stem equal to 0.34, 0.38, and 0.45 ml/g/min, respectively. Animals of the same age, after being placed in oxygen for 1 hr, had a mean arterial oxygen tension (Pa o ,) of 349 mm Hg; arterial carbon dioxide tension (Pa co ,) did not change from the level seen in animals kept in air. The CBF of nearly all structures was 20-30% lower in the hyperoxic newborns than in control animals. In 3-week-old puppies, CBF ranged between 1.41 (inferior colliculus) and 0.20 ml/g/min (centrum ovale), with average values for gray matter in the cerebral cortex, deep cerebral structures, and brain stem equal to 0.61, 0.72, and 0.93 ml/ g/min, respectively. Puppies at this age breathing oxygen attained a mean Pa o , of 357 mm Hg; again, Pa C o 2 values were not different from those in air. The oxygen effect on CBF in the 3-week-old animals was less than had been found at 2 days, there being far fewer structures in which the difference was significant. The smallest differences were in white matter ( -11%). Continuous exposure to oxygen for 1 week, followed by removal of the puppies to air for 2-3 days, resulted in values for CBF which were comparable with those found in control animals. Speculation

show abstract

Section: Effects Of Chronic Oxygen Exposurementioning

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Effect of Hyperoxia on the Cerebral Ciculation of the Newborn Puppy

Kennedy¹,

Grave²,

Jehle³

1971

Pediatr Res

View full text Add to dashboard Cite

show abstract

“…Turner, Lambertsen, Owen, Wendel & Chiodi (1957) studied six normal subjects breathing 21-80% 02. They controlled the PCO2 to a mean of 43 mmHg throughout, and found no change in CBF or cerebrovascular resistance.…”

Section: Resultsmentioning

confidence: 99%

The effect of high concentrations of inspired oxygen on middle cerebral artery blood velocity measured by transcranial Doppler

Bew

Field²,

Dw³

et al. 1994

Experimental Physiology

View full text Add to dashboard Cite

SUMMARYThe effects of high concentrations of inspired oxygen on cerebrovascular haemodynamics were studied in healthy human volunteers using transcranial Doppler measurements of middle cerebral artery blood velocity. If the end-tidal carbon dioxide level was kept constant, the measured blood velocity and the calculated Pulsatility Index showed no significant change when subjects were breathing 21, 40, 75 or 100% oxygen.

show abstract

“…It has been pointed out elsewhere, however, that the association of increased brain blood flow and rate of CMRco2 may not be real, and that the basis for adjustment of blood flow to neuronal activity need not be either rise in central Pco2 or fall in central Po2 (35). Evidence offered for this opposite view is that elevation of central Pco2, unaccompanied by concurrent arterial hypercapnia, does not increase blood flow through the brain (35)(36)(37).…”

Section: Resultsmentioning

confidence: 99%