[Effect of induced hypotension with prostaglandin E1 or trimetaphan on endocrine functions in surgical patients]

Twenty patients who underwent surgery of hip joint under enflurane anesthesia were studied to evaluate the effect of induced hypotension with prostaglandin E1 or trimetaphan on endocrine functions. Ten patients were given prostaglandin E1 and the remaining ten patients were given trimetaphan intravenously to maintain systolic blood pressure at about 80 mmHg. There were no significant differences between the two groups concerning plasma level of ACTH, cortisol, TSH, T3, T4, epinephrine and dopamine. However a significant difference in plasma norepinephrine levels was observed between them. Plasma norepinephrine levels after start of hypotension increased by 50% in the prostaglandin E1 group, but decreased by 50% in the trimetaphan group, when compared with each pre-hypotensive level. The data obtained suggest that the prostaglandin E1 would not influence ACTH-cortisol and thyroid functions, but may have a tendency to increase plasma norepinephrine levels in hypertensive patients complicated with pheochromocytoma.