Several recent studies have demonstrated that epidural anesthesia significantly increases the success of external cephalic version (ECV). In a retrospective review, Carlan et al. found that the use of an epidural increased the success of ECV from 24% to 59% (1). Two prospective, randomized trials demonstrated similar results, with success rates of 59% (3) and 69% (2) in the epidural groups compared to only 33% and 32% in controls. Finally, up to 56% of women who have failed ECV without anesthesia may subsequently have successful version with an epidural (4,11). It is clear that the use of epidural anesthesia dramatically increases the success of ECV and decreases the cesarean section rate for breech presentation. What remains to be debated is whether these benefits outweigh the costs and potential risks of the epidural. I will argue that, based on cost savings, safety, and increased acceptance of and comfort during the procedure, epidural for external cephalic version is warranted.
Each successful version generates estimated savings of $2,462 (5). Since the use of epidural anesthesia adds approximately 30 successful versions for every 100 attempts (i.e. from 25-30% success rate up to 55-60%), we can attribute 30% of this cost saving, or $738.60, directly to the epidural. This is more than enough to offset the cost of the epidural itself. Even if an epidural had only half the reported effect on the success of ECV, or an additional 15 successful versions per 100 attempts, the cost saving per epidural would be $369.30, which would probably still offset the cost of the epidural under current reimbursement schemes. Further, since many physicians plan delivery immediately after attempted ECV, the epidural could be used for labor analgesia if the version is successful or for the cesarean section if it is unsuccessful. This would limit any additional cost of the epidural attributable to the version, particularly those related to nursing or hospital charges. This makes the cost-benefit analysis even more favorable.
The second compelling reason to use an epidural during ECV is increased safety to the mother and the fetus. Ironically, safety has been argued as a reason not to use anesthesia during ECV. Several early reports on the use of general anesthesia for ECV raised concerns about the use of excessive force leading to an increased incidence of placental abruption, Rh isoimmunization, uterine rupture, cord prolapse, and other potentially catastrophic events (1). Indeed, fetal death was reported in up to 1% of women undergoing ECV under general anesthesia (7). In addition, mothers were at risk for aspiration of gastric contents during this procedure. The relevance of these data to current practice must be questioned. The use of b-mimetic drugs for uterine relaxation, continuous fetal monitoring and real time ultrasound has become routine during ECV, allowing the practitioner to closely monitor mother and baby, and greatly decrease the risk of these catastrophic events. To date, epidural anesthesia during ECV has been reported in 205 women (1-4,11). Maternal and fetal complication rates were quite low, with only a single study demonstrating a non-significant increase in the incidence of fetal bradycardia in the epidural group and no difference in neonatal outcome (1). Based on available data utilizing modern methods of fetal monitoring during ECV, the use of epidural anesthesia is not associated with an increase in maternal or fetal complications.
Conversely, epidural anesthesia may actually improve the safety of ECV. Major complications necessitating emergent delivery can occur during ECV. If the version is attempted under epidural anesthesia raised to a T-6 level (as has been reported), surgical delivery of the fetus can occur literally within one or two minutes after identifying a complication. The induction of general anesthesia, requiring pre-oxygenation, the onset of loss of consciousness and paralysis, and airway control, might take substantially longer. This additional time could be detrimental to a fetus in distress. In addition, general anesthesia is associated with a nearly 17-fold increase in anesthesia related maternal mortality (10). Carlan found that none of the women who had emergent C/S after ECV with an epidural required general anesthesia, while all such women in the control group did (1).
Of course, when addressing safety, one must consider the risks of the epidural itself. This anesthetic technique has been used in obstetrics for literally millions of deliveries, and its safety record has stood the test of time. However, complications can occur, ranging from back pain, to post-dural-puncture headache, to the extremely rare complications of nerve injury, epidural hematoma or abscess, and paralysis. However, as in the cost analysis, if one plans delivery immediately after attempted version, either by induction of labor or C/S, then most women would request or require regional anesthesia and the additional risk of the epidural attributable to the ECV is negligible. Thus, the use of epidural for ECV may decrease the risk to both baby and mother by facilitating immediate operative delivery and decreasing the likelihood of general anesthesia.
An increase in physician and maternal acceptance may be another reason to argue for the use of epidural anesthesia during ECV. Breech presentation occurs in 3-4% of all pregnancies (9). It accounts for nearly 20% of primary cesarean sections and this number is rising dramatically (6). Approximately 85% of all breech presentions are delivered by cesarean section (8). Although ECV could help to decrease this number, clearly it is not routinely employed. In one large series, only 203 of 1016 women (5) with non-cephalic presentation even attempted ECV. While medical contraindications to ECV do exist, other factors may limit the use of ECV. Physicians may hesitate to offer this modality because of a perception that it is not effective. Mothers may be hesitant to accept ECV because of the fear of pain. Epidural anesthesia would address both of these concerns. Whatever the reasons, it is clear that ECV does not currently play nearly a large enough role in the management of breech presentation. The use of epidural as an adjunct to ECV might reverse this state of affairs.
Treating maternal pain is the final and perhaps most compelling reason to use an epidural during ECV. Pain is the most frequent indication for termination of attempted ECV. While many obstetricians believe that pain is a useful marker to prevent the use of excessive force, this has never been proven. I can think of no other clinical scenario in which intolerable pain is an expected endpoint of a medical procedure. Alleviating maternal pain is the very foundation of obstetric anesthesia. To force women with breech presentation to choose between the pain of surgery and a painful version procedure when a safe, effective, readily available alternative exists is contrary to the heritage of obstetric anesthesia.
In conclusion, the use of epidural anesthesia increases the success of external cephalic version and decreases the cesarean section rate due to breech presentation. Epidural use would lead to annual savings of thousands of dollars in a busy obstetric unit, would make cesarean delivery safer and more rapidly available in an emergency, might increase the use of ECV, and would minimize the pain associated with this procedure. These are compelling reasons for its use.
References:
Stephen Pratt, MD
Department of Anesthesia and Critical Care
Beth Israel Deaconess Medical Center
Harvard Medical School