Neuraxial anesthesia and External Cephalic Version

Conclusions: Spinal Anesthesia (SA: hyperbaric bupivacaine 9mg + fentanyl 15mcg) increased the success rate and reduced pain for both primary and re-attempts of External Cephalic Version (ECV), whereas IV Anesthesia (IVA) using remifentanil infusion (0.1mcg/kg/min) only reduced the pain. There was no significant increase in the incidence of fetal bradycardia or emergency CS, with ECV performed under anaesthetic interventions. Relaxation of the abdominal muscles from SA appears to underlie the improved outcomes for ECV.
Editor’s key points: There is no consensus on best anaesthetic technique for external cephalic version (ECV). In this study, success at ECV was higher using spinal anaesthesia compared with remifentanil infusion or no intervention. Pain was also reduced in the remifentanil group but success at ECV was no different to the no intervention group. The effect of spinal anaesthesia in ECV may relate to relaxation of the abdominal musculature.

Neuraxial blockade is associated with minimal hospital and insurer cost changes in the setting of external cephalic version, while reducing the cesarean delivery rate.

It is both effective and cost-effective to utilize spinal anesthesia to perform ECV in term, nulliparous women with breech fetuses. Translation of this potentially impactful approach into broad obstetric practice should be undertaken.

Six RCTs met criteria for study inclusion. Regional anesthesia was associated with a higher external cephalic version success rate compared to intravenous or no analgesia (59.7% vs. 37.6%; pooled RR 1.58, 95% confidence interval [CI] 1.29-1.93). This significant association persisted when the data was stratified by type of regional anesthesia (spinal vs. epidural). The number needed to treat with regional anesthesia to achieve one additional successful ECV was 5. There was no evidence of statistical heterogeneity (p=0.32, I²=14.9%) or publication bias (Harbord test p=0.78). There was no statistically significant difference in the risk of cesarean delivery comparing regional anesthesia to intravenous or no analgesia (48.4% vs. 59.3%; pooled RR 0.80, 95% CI 0.55-1.17). Adverse events were rare and not significantly different between the two groups.

Neuraxial Anesthesia (NA) for External Cephalic Version (ECV) increased the risk of emergent cesarean delivery (CD) without impacting ECV success. These findings differ from previous randomized controlled trials (RCTs). The increased risk and decreased success of our ECVs compared to ECVs performed in the context of RCTs could be explained by patient selection, variation in operator experience or technique, or variation in anesthetic management. Future studies should further evaluate the risk of NA for ECV in true practice scenarios outside of RCTs.

Repeat ECV with spinal anesthesia after a failed first attempt without spinal anesthesia increased vertex presentation at birth and decreased the rate of cesarean delivery.

Results: A total of 240 subjects were enrolled, and 239 received the intervention. External cephalic version was successful in 123 (51.5%) of 239 patients. Compared with bupivacaine 2.5 mg, the odds (99% CI) for a successful version were 1.0 (0.4 to 2.6), 1.0 (0.4 to 2.7), and 0.9 (0.4 to 2.4) for bupivacaine 5.0, 7.5, and 10.0 mg, respectively (P = 0.99). There were no differences in the cesarean delivery rate (P = 0.76) or indication for cesarean delivery (P = 0.82). Time to discharge was increased 60 min (16 to 116 min) with bupivacaine 7.5 mg or higher as compared with 2.5 mg (P = 0.004).
Conclusions: A dose of intrathecal bupivacaine greater than 2.5 mg does not lead to an additional increase in external cephalic procedural success or a reduction in cesarean delivery.