[Cerebral blood flow and metabolism under "diazanalgesia" (author's transl)]

"Diazanalgesia" employs the combination diazepam + fentanyl. Its effects were studied on regional cerebral blood flow and oxygen metabolism in 8 normal subjects, who were examined angiographically. During diazanalgesia, cortical blood flow falls by 56 p. 100. The mean hemispheric flow calculated over 10 min falls by 34 p. 100. Cerebral O2 consumption (VcO2) falls by 34 p. 100. However, large individual variations are found which suggests that the fall in blood flow is not due solely to the decrease in O2 metabolism. The decreases in flow are not proportional to the amount fentanyl, and there is no direct relation between falls in VcO2 and amount of fentanyl. Cerebral vaso-reactivity to CO2 persists but is reduced under diazanalgesia compared with the waking state.