[Effects of high doses of morphinomimetics (fentanyl and fentathienyl) on the cerebral circulation in normal subjects].
The effects of large doses of morphinomimetics on the cerebral circulation were studied in 12 normal subjects (fentanyl 16 microgram/kg in 6 patients and fentathienyl 1.9 microgram/kg in 6 others). Mean hemispheric flow (corrected to a pCO2 of 40) changed from 50.8 +/- 4.4 ml/100 g/min in the conscious state to 50.3 +/- 25.1 under the influence of fentanyl, and flow in the grey matter from 78.8 +/- 10 to 84.3 +/- 65 ml/100 g/min. Mean flow changed from 49 +/- 3.1 ml/100 g/min in the conscious state to 55.5 +/- 10 under the influence of fentathienyl, flow in the grey matter increasing from 75 +/- 9 to 81.8 +/- 14.4. Whilst there was no variation in mean flow rates under the influence of morphinomimetics, individual behaviour was very variable, in particular in the case of fentanyl, the changes produced by fentathienyl being much more homogeneous. There was no obvious modification in the distribution of regional flow by these morphinomimetics. Individual variations in flow correlated perfectly with individual variations in cerebral oxygen consumption. Vascular reactivity to CO2 was increased b morphinomimetics. In one subject, fentanyl produced a very marked increase in cerebral blood flow (+ 104 p. 100) for which no explanation could be found.
[Effects of high doses of morphinomimetics (fentanyl and fentathienyl) on the cerebral circulation in normal subjects]. The effects of large doses of morphinomimetics on the cerebral circulation were studied in 12 normal subjects (fentanyl 16 microgram/kg in 6 patients and fentathienyl 1.9 microgram/kg in 6 others). Mean hemispheric flow (corrected to a pCO2 of 40) changed from 50.8 +/- 4.4 ml/100 g/min in the conscious state to 50.3 +/- 25.1 under the influence of fentanyl, and flow in the grey matter from 78.8 +/- 10 to 84.3 +/- 65 ml/100 g/min. Mean flow changed from 49 +/- 3.1 ml/100 g/min in the conscious state to 55.5 +/- 10 under the influence of fentathienyl, flow in the grey matter increasing from 75 +/- 9 to 81.8 +/- 14.4. Whilst there was no variation in mean flow rates under the influence of morphinomimetics, individual behaviour was very variable, in particular in the case of fentanyl, the changes produced by fentathienyl being much more homogeneous. There was no obvious modification in the distribution of regional flow by these morphinomimetics. Individual variations in flow correlated perfectly with individual variations in cerebral oxygen consumption. Vascular reactivity to CO2 was increased b morphinomimetics. In one subject, fentanyl produced a very marked increase in cerebral blood flow (+ 104 p. 100) for which no explanation could be found.