Controlled arterial hypotension during neurosurgical operations.

Controlled arterial hypotension was applied in 62 hyperventilated patients during neurosurgical operations. Hypotension was obtained using trimetaphan (19 cases), trimetaphan and halothane (32 cases) and sodium nitroprusside (11 cases). It was found that the action of sodium nitroprusside was the quickest and lasted the shortest, which considerably facilitated the control of hypotension. Halothane permitted hypotension to be obtained rapidly but in certain cases it prolonged the hypotensive action of trimetaphan.