///2016 Abstract Details
2016 Abstract Details2019-07-15T10:10:51-05:00

A Randomized Controlled Trial Comparing Combined Spinal- Epidural Dosing Strategies for External Cephalic Version

Abstract Number: F-29
Abstract Type: Original Research

Laurie A Chalifoux MD1 ; Laurie A Chalifoux MD2; John T Sullivan MD, MBA3; Robert J McCarthy PharmD4

Introduction: Breech presentation is a leading cause of cesarean delivery (CD). ACOG recommends that external cephalic version (ECV) should be offered whenever possible to reposition the fetus to facilitate vertex vaginal delivery, thus avoiding the morbidity associated with CD. Anesthetic techniques for ECV range from no analgesia to systemic opioids to neuraxial techniques. Meta-analyses of RCTs suggest that neuraxial techniques employing higher doses of local anesthetic result in increased ECV success1.

Methods: We conducted a prospective, randomized trial to assess the impact of bupivacaine dose (2.5, 5, 7.5, 10 mg) with fentanyl 15 mcg as part of a combined spinal-epidural on the success rate of ECV for breech presentation. Patients and OBs were blinded to group assignment. Secondary outcomes included mode of delivery, patient pain scores and satisfaction, Obstetricians’ perceived abdominal relaxation, length of stay, incidence of complications, and hypotension requiring vasopressor treatment.

Results: 240 subjects provided informed consent and 229 completed the study. ECVs were performed by 79 obstetricians with median performed 2 [1 to 18]. There was no difference among groups in ECV success (P=0.99). (Table) The mode of delivery and indication for CD were similar among groups. One emergent CD occurred in each group temporally related to the ECV procedure. Obstetrician perception of abdominal relaxation was similar among groups. Pain scores (VAS) for the procedure were low in all groups. Hypotension requiring treatment and time to discharge were increased with escalating bupivacaine doses.

Discussion: Our results do not support the hypothesis of a neuraxial dose-response effect on ECV success. Previous trials comparing neuraxial technique to nothing or to systemic opiate for ECV were limited by lack of patient and obstetrician blinding. Our overall ECV success rate of 51% was comparable to our previously published rates, but lower than other studies using high dose neuraxial techniques2. It is unclear why our success was relatively low, but this may be related to institutional practice (e.g., technique, number of attempts, threshold to abort procedure). We conclude that escalating bupivacaine dose does not confer an increase in ECV success or NSVD, but does incur an increase in hypotension and prolong length of stay.

1. Sullivan Int J Obstet Anesth 2009;18(4)

2. Weiniger Br J Anaesth 2010;104(5)

SOAP 2016