[Evaluation of maternal acid-base status after different doses of spinal sufentanil for cesarean section and its effects on the neonates.].

Background And Objectives: Spinal sufentanil in obstetric anesthesia promotes immediate pain relief, improves anesthesia quality and prolongs postoperative analgesia, its major side effect being respiratory depression. This study aimed at evaluating maternal acid-base status after different doses of spinal sufentanil associated to hyperbaric bupivacaine for cesarean section, and its effects on neonates' vitality.

Methods: Participated in this study 40 full term pregnant women, physical status I (ASA), aged 17 to 35 years, who were submitted to elective cesarean section under spinal anesthesia. Patients were distributed into two equal groups: Group I received 12 mg of hyperbaric 0.5% bupivacaine associated to 2.5 microg sufentanil; Group II received 12 mg of hyperbaric 0.5% bupivacaine associated to 5 microg sufentanil. The following parameters were evaluated: maternal acid-base status through arterial blood gas analysis before anesthesia and after birth, SpO2, hemodynamic changes, neonates' vitality evaluated through Apgar Index and umbilical cord blood gas analysis, in addition to the incidence of side effects.

Results: There were no differences between groups in all parameters evaluated, with a mild maternal metabolic acidosis compensated in both groups both before anesthesia and soon after birth, however without clinical repercussions. Neonates showed good vitality and normal blood gas analysis.

Conclusions: The association of spinal hyperbaric 0.5% bupivacaine to low sufentanil doses has shown to be safe to both mother and neonate, preserving their hemodynamic and acid-base status.