INTRATHECAL SUFENTANIL PRODUCES SENSORY CHANGES WITHOUT HYPOTENSION IN MALE-VOLUNTEERS

Background: Intrathecally administered sufentanil is frequently associ ated with hypotension and sensory changes in women undergoing labor. I n this study, the authors examined whether intrathecally administered sufentanil has similar effects in pain-free individuals with low conce ntrations of progesterone(i.e. male volunteers), Methods: Ten male vol unteers were randomly assigned to receive an intrathecal injection of either 10 mu g sufentanil or saline in a double-blind fashion. Blood p ressure, heart rate, oxyhemoglobin saturation, and temperatures from t he body core and skin of the calf and ipsilateral great toe were recor ded. Cold and pin prick sensation, motor block, and visual analogue sc ores for sedation, pruritus, and nausea also were assessed. Current pe rception thresholds using the Neurometer current perception threshold instrument (Neurotron, Inc., Baltimore, MD) mere determined for three frequencies (2,000, 250, and 5 Hz, corresponding to stimulation of A b eta, A partial derivative, and C fibers, respectively) on the upper an d lower extremities, Results: Pruritus and sensory changes to pin pric k and cold occurred in the sufentanil group but not the saline group. Neither group had a significant change in blood pressure, heart rate, oxyhemoglobin saturation, sedation, or core temperature. There was a c linically insignificant difference in the calf minus toe temperature i ndex between the saline and sufentanil groups. There was a small incre ase in the current perception thresholds at 250 Hz in the sufentanil g roup. Conclusions: Intrathecally administered sufentanil did not affec t blood pressure in male volunteers. The other effects of sufentanil, however, were similar to those observed in women undergoing labor. Thi s suggests that the hypotension occurring in these women after intrath ecally administered sufentanil is secondary to relief of pain, rather than to a sympathectomy.