INDUCED HYPOTENSION AS AN AID TO INTRACRANIAL SURGERY

• Hypotension induced with trimethaphan has been used in connection with ether anesthesia in a series of 295 craniotomies. This series was compared with another of 201 cases in which hypotension was not induced. Blood pressures below 60 mm. Hg were associated with higher morbidity and mortality rates ascribed to cerebral damage due to stagnant anoxia. Prolongation of hypotension at levels of 70 to 100 mm. Hg did not increase morbidity or mortality. It probably facilitated operative procedure by decreasing the bleeding from small vessels and may be advisable when massive bleeding is anticipated. In the two series, however, operating times were practically equal, as were the percentages of patients requiring transfusions of 2,000 cc. or more of blood.