Spinal anesthesia for elective ceasarean section: use of different doses of hyperbaric bupivacaine associated with morphine and clonidine.

PURPOSE To comparatively study the efficacy and maternal and fetal side-effects of two doses of bupivacaine associated with morphine and clonidine, administered by the subarachnoid route for cesarean section. METHODS The study included 66 pregnant women at term, distributed into two groups. GI: bupivacaine 8.0 mg (1.6 mL) + clonidine 75 µg (0.5 mL) + morphine 100 µg (1.0 mL) and GII: bupivacaine 10 mg (2.0 mL) + clonidine 75 µg (0.5 mL) + morphine 100 µg (1.0 mL). The following parameters were assessed: onset and maximum level of sensory block; quality of intraoperative and postoperative analgesia; degree and duration of motor block; maternal repercussions and Apgar score. RESULTS The onset of sensory block, quality of intraoperative analgesia and total duration of analgesia were similar in both groups; maximum extent of sensory block predominated in T4; maximum degree of motor block (Bromage 3); time motor block regression was significantly longer in GII; Hemodynamic, respiratory repercussions, adverse maternal effects and Apgar scores were similar between groups. In both groups, there was a predominance of drowsy or sleeping patients. CONCLUSION The addition of morphine and clonidine to low doses of hyperbaric bupivacaine produced adequate anesthesia for cesarean section and good postoperative analgesia, without any maternal and fetal repercussions.