THE EFFECTS OF MATERNAL POSITION DURING INDUCTION OF COMBINED SPINAL-EPIDURAL ANESTHESIA FOR CESAREAN DELIVERY

Combined spinal-epidural anesthesia (CSE) is a popular technique for c esarean delivery. Regional blocks in obstetrics are often performed wi th the parturient in the sitting position because the midline may be r ecognized more easily than in the lateral decubitus position. When con ventional spinal anesthesia is performed in the sitting position, the patient is placed supine immediately after drug injection. In contrast , when CSE is performed with the woman sitting, there is a delay in as suming the supine position because of epidural catheter placement, whi ch may affect the incidence of hypotension. Healthy women, at term of pregnancy, about to undergo an elective cesarean section under CSE, we re randomly assigned to the sitting or lateral recumbent position for initiation of the block. All parturients were given 1000 mt of lactate d Ringer's solution in the 15 min preceding induction and an additiona l 300-500 mt while the actual block was being performed. On completion of the CSE, they were turned to the supine position with left uterine displacement. A second anesthesiologist, blinded to the woman's posit ion during CSE, evaluated the sensory level of anesthesia, maternal he art rate, blood pressure, oxygen saturation, need for ephedrine, and o ccurrence of nausea and vomiting. Results are expressed as mean +/- so . Twelve women were studied in the sitting group and 10 were studied i n the lateral recumbent group. The severity and duration of hypotensio n were greater in those parturients who had CSE induced in the sitting (47% +/- 7% and 6 +/- 3 min, respectively) compared with the lateral recumbent position (32% +/- 14% and 3 +/- 2 min, respectively). Women in the sitting group also required twice as much ephedrine(38 +/- 18 m g) to correct hypotension compared with the other group (17 +/- 12 mg) . In conclusion, the severity and duration of hypotension were greater when CSE was induced in the sitting compared with Be lateral decubitu s position. Implications: We studied the induction of combined spinal- epidural anesthesia (CSE) in the sitting versus lateral recumbent posi tions in healthy women undergoing a scheduled cesarean delivery. The s everity and duration of hypotension were greater when CSE was induced in the sitting position. Thus, the position used for induction of CSE should be among the factors considered when there is greater maternal or fetal risk from hypotension.