[Hyperbaric bupivacaine: a randomized double-blind trial of different doses with or without fentanyl for cesarean section under spinal anesthesia].

OBJECTIVES

To compare the effects of spinal anesthesia with different doses of hyperbaric bupivacaine with or without fentanyl in patients undergoing cesarean section.

MATERIAL AND

METHODS

Prospective study enrolling 50 ASA 1-2 patients undergoing cesarean section, randomized to 5 treatment groups. Groups A, B, C, and D received 15 microg of fentanyl and group X received no fentanyl. The doses of hyperbaric bupivacaine given in each group were as follows: 10 mg in Group A, 11 mg in group B, 12 mg in group C, 13 mg in group D, and 14 mg in group X.

RESULTS

Patients in groups A and B had greater hemodynamic stability than patients in groups C, D, or X (P < 0.05). The incidence of hypotension was 70% in group C and 80% in groups D and X. The sensory block reached level T4 in groups D and X and the motor block was complete in all cases. Postoperative analgesia lasted longer in group D with a mean (SD) duration of 202 (25) minutes than in group X with a mean duration of 194 (19) minutes. Assessment on a visual analog scale was under 3 in all groups except group A, where 2 patients required administration of propofol.

CONCLUSIONS

Acceptable operative conditions with a low incidence of hypotension are provided with an 11 mg dose of hyperbaric bupivacaine.