[Cerebral blood volume, cerebral hemoglobin and cytochrome AA3 during hypotension induced by prostaglandin E1 or epidural anesthesia under general anesthesia].

The effect of hypotension induced by PGE1 or epidural anesthesia under general anesthesia on cerebral blood volume (CBV), cerebral tissue hemoglobin, cytochrome AA3 was studied using a near infrared spectrophotometry in 20 patients undergoing abdominal operation. In PGE1 group (n = 10), CBV, cerebral oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) were unchanged during hypotension. However, cerebral HbO2 decreased and Hb increased slightly in a case of severe hypotension more than 40 percent of control, but CBV did not show any significant change. On the other hand, in epidural anesthesia group, HbO2 decreased significantly along with MAP reduction (r = 0.84) and Hb increased slightly. Cytochrome AA3 did not show any significant changes in both groups. From these results, we concluded that PGE1 drip infusion was better than epidural anesthesia to sustain the cerebral blood volume during hypotension.