Effect on canine cerebral blood flow of two common pressor agents during prolonged halothane anesthesia

Inasmuch as prolonged halothane anesthesia is often associated with hypotension, the effects of pressor agents possibly employed to adjust this hypotension on cerebral blood flow are of interest. In dogs, after prolonged halothane anesthesia, there was a marked difference in the effects of phenylephrine and angiotensin on cerebral blood flow at dosages which promote moderate rises in blood pressure. Phenylephrine had no effect whereas angiotensin had a significantly enhancing effect on cerebral blood flow.