HYPOTENSION - A MAJOR FACTOR LIMITING RECOVERY FROM CEREBRAL ISCHEMIA

When no vasopressor agents were administered, rabbits subjected to cerebral ischemia for 10 or 15 minutes showed marked hypotension in the post-ischemic period (blood pressures of 20-40 mm. Hg), and there was no recovery of neural function in the course of 2 hours. However, when metaraminol or adrenalin was administered immediately after the ischemia to restore the blood pressure to normal levels, all animals subjected to 10 minutes of ischemia recovered all of the parameters of neural function measured, and most of the animals subjected to 15 minutes of ischemia recovered most of the parameters, including spontaneous respirations, pupillary light reflexes, corneal and pain withdrawal reflexes. After 30 minutes of ischemia, about half the animals regained gasping respirations and hippus pupillary reaction to light. Thus, prompt restoration of normal blood pressure may permit recovery following periods of ischemia that would otherwise lead to irreversible damage. © 1969.