The effects of midazolam on cerebral blood flow and oxygen consumption and its interaction with nitrous oxide.

The effects of the intravenous infusion of midazolam on cerebral blood flow (CBF) and cerebral oxygen consumption (CMRO2) were measured in rats in the presence and absence of nitrous oxide. Midazolam produced 40-45% decreases in CBF with no difference in response between nitrous oxide and nitrogen-ventilated rats. CMRO2 decreased 55% during midazolam infusion in rats ventilated with nitrogen, significantly more (P less than 0.05) than in rats ventilated with nitrous oxide (35%). We conclude that cerebrovascular responses to midazolam infusion were not altered by nitrous oxide and suggest that nitrous oxide may slightly but significantly stimulate brain metabolism during midazolam infusion.