A prospective comparison of vasopressor requirement and hemodynamic changes during spinal anesthesia for cesarean delivery in patients with multiple gestation versus singleton pregnancy.

BACKGROUND: It is commonly taught that patients with multiple gestation pregnancy are prone to more severe hypotension during spinal and epidural anesthesia compared to those with singleton pregnancy. However, few quantitative data are available to support this claim. In this study, we prospectively compared vasopressor requirement and hemodynamic changes in patients with multiple gestation versus singleton pregnancy during spinal anesthesia for elective cesarean delivery.
METHODS: Forty parturients with multiple gestation and 60 singleton controls who had identical anesthetic management during spinal anesthesia for elective cesarean delivery were enrolled. After IV prehydration, patients received intrathecal bupivacaine-fentanyl and were tilted to the left. A metaraminol infusion was titrated with the target of maintaining systolic blood pressure at 90%-100% of baseline. Vasopressor dose, minimum and maximum values for systolic blood pressure and the incidences of hypotension, hypertension, and nausea/vomiting were compared.
RESULTS: All outcome variables were similar between groups. The total dose of metaraminol required until uterine incision was similar in multiple gestation pregnancy (median 2.9 [interquartile range 2.0-3.7] mg) when compared with singleton pregnancy (median 3.1 [interquartile range 2.3-3.9] mg, P = 0.25; median difference 0.30 mg, 95% confidence interval of difference -0.20 to 0.90 mg). Neonatal outcome was similar between groups.
CONCLUSION: Patients with multiple gestation pregnancy do not exhibit greater hemodynamic instability during spinal anesthesia for cesarean delivery compared to those with singleton pregnancy.