Physiology of Cerebral Bloodflow

The influence of ketamine and other intravenous anaesthetic agents on cerebral blood flow in the sheep

“…Because of the surgical preparation involved rCBF could not be measured in conscious animals, hence values were compared to those obtained under steady state anaesthesia with halothane in N 2 0 / 0 2 . The influence of arterial carbon dioxide levels on rCBF has been precisely delineated in dogs (Harper, 1965) and humans (Cohen, Wollman, Alexander, Chase & Behar, 1964) and the results of the present study agree very closely with their findings that rCBF increases linearly with P,C02 in the range of 30-60 mm Hg (4-8 Kpa).…”

The influence of ketamine and other intravenous anaesthetic agents on cerebral blood flow in the sheep

“…Because of the surgical preparation involved rCBF could not be measured in conscious animals, hence values were compared to those obtained under steady state anaesthesia with halothane in N 2 0 / 0 2 . The influence of arterial carbon dioxide levels on rCBF has been precisely delineated in dogs (Harper, 1965) and humans (Cohen, Wollman, Alexander, Chase & Behar, 1964) and the results of the present study agree very closely with their findings that rCBF increases linearly with P,C02 in the range of 30-60 mm Hg (4-8 Kpa).…”

Dependence of Oxygen Delivery on Blood Flow in Rat Brain: A 7 Tesla Nuclear Magnetic Resonance Study

“…However, the observed changes in blood pressure were within the expected range over which cerebral autoregu lation occurs in the mature rat brain (60 to 150 mm Hg; Hernandez et al, 1978). In addition, CBF was shown to be independent of mean arterial pressure between 70 to 120 mm Hg for a particular anesthesia level (Harper, 1965(Harper, , 1966. The l3 C fractional enrichment ratio of [C4] glutamate/[C l]-glucose at the end of each experiment for each condition was insignificantly different from the oth ers ( Table 2).…”

Cerebral blood flow and metabolism during open-heart surgery

“…The mean arterial blood pressure fell at the onset of perfusion to 44 mmHg, which is below the value at which, in normal circumstances, autoregulation can preserve a normal cerebral blood flow (Harper, 1965). It is possible, however, that the reduction in cerebral blood flow which would be expected to result from this hypotension did not occur because the overall flow rate from the oxygenator was high (80 ml/kg per minute).…”

The influence of ketamine and other intravenous anaesthetic agents on cerebral blood flow in the sheep

“…Because of the surgical preparation involved rCBF could not be measured in conscious animals, hence values were compared to those obtained under steady state anaesthesia with halothane in N 2 0 / 0 2 . The influence of arterial carbon dioxide levels on rCBF has been precisely delineated in dogs (Harper, 1965) and humans (Cohen, Wollman, Alexander, Chase & Behar, 1964) and the results of the present study agree very closely with their findings that rCBF increases linearly with P,C02 in the range of 30-60 mm Hg (4-8 Kpa).…”

Dependence of Oxygen Delivery on Blood Flow in Rat Brain: A 7 Tesla Nuclear Magnetic Resonance Study

“…However, the observed changes in blood pressure were within the expected range over which cerebral autoregu lation occurs in the mature rat brain (60 to 150 mm Hg; Hernandez et al, 1978). In addition, CBF was shown to be independent of mean arterial pressure between 70 to 120 mm Hg for a particular anesthesia level (Harper, 1965(Harper, , 1966. The l3 C fractional enrichment ratio of [C4] glutamate/[C l]-glucose at the end of each experiment for each condition was insignificantly different from the oth ers ( Table 2).…”

Cerebral blood flow and metabolism during open-heart surgery

“…The mean arterial blood pressure fell at the onset of perfusion to 44 mmHg, which is below the value at which, in normal circumstances, autoregulation can preserve a normal cerebral blood flow (Harper, 1965). It is possible, however, that the reduction in cerebral blood flow which would be expected to result from this hypotension did not occur because the overall flow rate from the oxygenator was high (80 ml/kg per minute).…”

The influence of ketamine and other intravenous anaesthetic agents on cerebral blood flow in the sheep

“…Because of the surgical preparation involved rCBF could not be measured in conscious animals, hence values were compared to those obtained under steady state anaesthesia with halothane in N 2 0 / 0 2 . The influence of arterial carbon dioxide levels on rCBF has been precisely delineated in dogs (Harper, 1965) and humans (Cohen, Wollman, Alexander, Chase & Behar, 1964) and the results of the present study agree very closely with their findings that rCBF increases linearly with P,C02 in the range of 30-60 mm Hg (4-8 Kpa).…”

Dependence of Oxygen Delivery on Blood Flow in Rat Brain: A 7 Tesla Nuclear Magnetic Resonance Study

“…However, the observed changes in blood pressure were within the expected range over which cerebral autoregu lation occurs in the mature rat brain (60 to 150 mm Hg; Hernandez et al, 1978). In addition, CBF was shown to be independent of mean arterial pressure between 70 to 120 mm Hg for a particular anesthesia level (Harper, 1965(Harper, , 1966. The l3 C fractional enrichment ratio of [C4] glutamate/[C l]-glucose at the end of each experiment for each condition was insignificantly different from the oth ers ( Table 2).…”

Cerebral blood flow and metabolism during open-heart surgery

“…The mean arterial blood pressure fell at the onset of perfusion to 44 mmHg, which is below the value at which, in normal circumstances, autoregulation can preserve a normal cerebral blood flow (Harper, 1965). It is possible, however, that the reduction in cerebral blood flow which would be expected to result from this hypotension did not occur because the overall flow rate from the oxygenator was high (80 ml/kg per minute).…”