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Anesth Analg 2002;94:1589-1592 © 2002 International Anesthesia Research Society
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Abstract |
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External cephalic version (ECV) has been successfully used to decrease the fetal and maternal morbidity and costs of cesarean delivery. As there are limited data regarding the use of central neuraxial blockade in the setting of previously failed ECV attempts, we sought to evaluate the efficacy and safety of spinal and epidural anesthesia in this setting. A retrospective review of all ECV attempts performed by a single experienced obstetrician between 1995 and 1999 was conducted. Standardized tocolytic and anesthetic regimens were used. A total of 77 patients underwent ECV attempts; of these, 37 (48%) were unsuccessful, 15 of which consented to further attempts with anesthesia. Neuraxial anesthesia was associated with frequent ECV success in both multiparous 4/4 (100%) and nulliparous 9/11 (82%) parturients. Overall 5/6 (83%) and 8/9 (89%) (P = NS) ECV attempts were successful with spinal and epidural anesthesia, respectively, with 2/5 (40%) and 6/8 (75%) (P = NS) resulting in vaginal deliveries. One successful ECV in the epidural group had an urgent cesarean delivery for persistent fetal bradycardia with good neonatal and maternal outcomes. We conclude central neuraxial anesthesia promotes successful ECV after previously failed ECV attempts.
IMPLICATIONS: Our retrospective analysis of central neuraxial techniques, both epidural and spinal anesthesia, noted a significant success rate in the setting of previously failed external cephalic version attempts.
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Introduction |
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Occurring in approximately 3%–5% of term pregnancies (1), breech fetal presentations can significantly alter obstetric and anesthetic management. External cephalic version (ECV) is a method by which manual external pressure is applied to the maternal abdomen to change the position of a fetus from a breech to cephalic presentation. It has been successfully used to decrease the fetal and maternal morbidity and costs associated with an operative delivery (1,2).
Although central neuraxial techniques improve the success rate of ECVs, only two studies have examined the use of such techniques after a previously failed ECV attempt (3,4). In this setting, the smaller overall success rates most likely reflect the stability of the fetal position; however, other variables may play an important role. A closer analysis of these variables, including the timing of the reattempt and the use of tocolytics, reveal that the reattempt conditions may have been suboptimal.
Anecdotally, we perceived our ECV success rate to be high, even in the setting of failed ECVs reattempted with central neuraxial anesthesia. The purpose of this study was to determine our true success rate and identify characteristics that enabled success. We hypothesized that immediately reattempting failed ECVs with central neuraxial blockade, using standardized tocolytic and anesthetic protocols, and performing ECVs with the same experienced obstetrician were factors responsible for success. Moreover, although only epidural techniques have been reported in this setting, we speculated that spinal anesthetic techniques could be associated with favorable success rates as well.
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Methods |
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After approval by the hospital’s Human Research Committee, the records of all ECV attempts performed by a single senior obstetrician during the years 1995–1999 were reviewed. According to the obstetrician’s protocol, ECV attempts were performed only if the parturient had a singleton fetus older than 36 wk, intact membranes, and normal obstetrical sonograms. ECV attempts were not offered to patients with uterine anomalies, previous uterine operations, current vaginal bleeding or labor. All ECV attempts followed the placement of an IV line and the provision of subcutaneous terbutaline 0.25 µg and were performed with ultrasonographic guidance and continuous fetal heart rate monitoring. Complications including placental abruption and fetal distress were recorded. The obstetrician’s practice for each ECV trial was to perform no more than three attempts. A successful version was defined as a conversion from breech to cephalic presentation.
If the initial ECV trial failed, the parturient was immediately requested to consider another trial with anesthesia. After consent, electrocardiogram, pulse oximetry, and noninvasive blood pressure monitors were placed and an oxygen face mask with a flow of 5–10 L/min was applied. Prehydration with 1000 mL of lactated Ringer’s solution and a second dose of subcutaneous terbutaline 0.25 µg were given. Central neuraxial blockade was performed within 30 min of the completion of the primary ECV trial with either a spinal, in the form of a combined spinal epidural (intrathecal hyperbaric 1.5% lidocaine 45–60 mg with fentanyl 10 µg), or an epidural (2% lidocaine with epinephrine 1:200,000 15–20 mL) anesthetic. Although the type of neuraxial blockade administered was at the discretion of the attending anesthesiologist, the drugs and doses used were determined by departmental protocol. Ephedrine was administered as required to treat hypotension after the blockade. Once an anesthetic level was obtained (>T6), no more than three ECV attempts were made with the monitoring as described above. If the first attempt was unsuccessful, IV nitroglycerin 50 µg was given before the second attempt to provide additional uterine relaxation. If the second attempt failed, nitroglycerin 100 µg was given before the third attempt. After ECV attempts, the patients were induced for labor, delivered by cesarean section, or discharged from the hospital according to the ECV outcome and the obstetrician’s protocols.
Data are presented as mean ± SD for continuous variables or as number (%) for discrete variables. Differences between continuous variables were tested by Student’s t-tests; associations were tested by 
2 analysis or Fisher’s exact test, where appropriate. P values < 0.05 were considered statistically significant. All analyses were performed with StatView Version 5.0 for Students (SAS Institute, Inc, Cary, NC).
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Results |
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Seventy-seven versions were attempted during the study period of which 37 (48%) were unsuccessful on first attempt without anesthesia. Fifteen parturients consented to another attempt with anesthesia. No significant differences were observed in terms of maternal or fetal characteristics between patients undergoing versions with and without anesthesia (Table 1), except more nulliparous parturients were in the spinal group. The success rates in nulliparous parturients reattempted with spinal and epidural anesthesia were 4/5 (80%) and 5/6 (83%) (P = NS), respectively. Success rates in multiparous parturients reattempted with spinal and epidural anesthesia were 1/1 (100%) and 3/3 (100%) (P = NS). High ECV success rates were noted in nulliparous (9/11 [82%]) and multiparous (4/4 [100%]) (P = 0.36) parturients, respectively. Overall, with the provision of spinal and epidural anesthesia respectively, 5/6 (83%) and 8/9 (89%) (P = NS) ECV attempts were successful.
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Eight patients used nitroglycerin after the first ECV attempt to a cumulative dose of 150 µg with 6/8 (75%) obtaining success (2/3 and 4/5 in the spinal and epidural groups, respectively). One ECV attempt in both the spinal and epidural groups was associated with fetal bradycardia of sufficient duration or intensity to warrant consideration of an urgent cesarean delivery. Despite successful versions in both of these patients, the fetal bradycardia persisted in the patient with the epidural anesthetic, and a cesarean delivery was commenced; the neonate was given Apgar scores of 8 and 9 at 1 and 5 min, respectively. No maternal or fetal complications were observed in the other patients. The final outcome of patients is noted in Figure 1. Of the patients who had successful ECV attempts under spinal and epidural anesthesia, 2/5 (40%) and 6/8 (75%) (P = 0.2) ultimately resulted in vaginal deliveries. In addition to the cesarean delivery noted above, one successful version in both the spinal and epidural groups underwent a cesarean delivery for failure to progress.
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Discussion |
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Our study supports the use of central neuraxial techniques (both epidural and spinal anesthesia) to increase the success rate of previously failed ECV attempts. As such, our success rate of 89% with epidural anesthesia compares favorably in this setting with the experience of Rozenberg et al. (4) and Neiger et al. (3), who observed successful ECV in 39.7% (27/68) and 56% (9/16) of their patient populations, respectively. In addition, we report for the first time a similarly high success rate with the use of spinal anesthesia in the setting of previously failed ECV attempts. The use of the spinal technique has only been reported for primary ECV attempts, where analgesic doses were used with contrasting results. Dugoff et al. (5) noted no improvement with the intrathecal administration of bupivacaine 2.5 mg with sufentanil 10 µg, whereas Birnbach et al. (6) noted a significant improvement (80% versus 33%) with the use of sufentanil 10 µg alone. Reasons for these contrasting outcomes may ultimately reflect differences in obstetric practice, such as how much force is applied and/or how much maternal discomfort is tolerated for a given level of analgesia or anesthesia. As a consequence, whether ECV version success can be predictably produced with analgesic versus anesthetic doses using spinal techniques or whether the results of such studies can be extrapolated to other practices will require further investigation. This being said, the findings of Birnbach et al. (6) and this study at least validate the potential value of spinal techniques in both primary and reattempted ECVs.
Of interest, our experience with nulliparous parturients yielded success rates of 83% and 80% with epidural and spinal anesthesia, respectively. Although multiparous parturients were associated with 100% success in both the epidural and spinal groups, our experience with nulliparous parturients was significantly more than previously reported. Rozenberg et al. (4), in the same setting with nulliparous parturients provided epidural anesthesia, reported a 28.6% success rate, and although Neiger et al. (3) did not separately report parity status, significantly better success rates were found with greater parity. Our findings also suggest that fewer nulliparous parturients without anesthesia result in a successful ECV and are in agreement with other primary ECV attempt studies (7) both with and without anesthesia that note greater ECV success with higher parity.
We attribute our ECV success rate principally to the use of central neuraxial blockade, which has been previously reported to significantly improve the ECV outcome even for primary attempts (3,4,8,9). As discussed by others, this is most likely attributable to the abdominal wall muscle relaxation, the improvement in patient comfort produced during the ECV attempt, and the subsequent ability of the obstetrician to apply a more concerted attempt (6,8). In addition, three other determinants may have contributed to the level of success observed, particularly in nulliparous parturients.
First, the use of an experienced obstetrician was most likely beneficial. Although this fact must be applied with caution, as the number and experience of the obstetricians performing the ECVs were not disclosed in previous reports, it agrees with the clinical observation that the success of any technique varies with practitioners and their experience. Teoh (10) noted a learning curve of 20 ECV attempts before proficiency with the technique was obtained. As the frequency of ECV attempts is limited even in busy clinical centers, it may take years for a single obstetrician to gain this level of experience. As in our study, the use of the same experienced obstetrician both before and after the central neuraxial blockade eliminated the participation of different obstetricians with different abilities; this eliminated a strong potential confounder noted in all previous studies on this subject. Thus, our results cannot be attributed to the use of a more successful obstetrician in the postanesthesia attempts or a small background success rate in the preanesthesia attempts (9). Of note, our results suggest that even obstetricians with high primary ECV success rates without central neuraxial techniques can benefit from reattempting failed ECVs with such techniques.
Second, immediately reattempting the ECV with central neuraxial blockade most likely improved our overall success rate. In contrast to previous reports (3,4) that delayed the ECV reattempt with epidural anesthesia at least until the 38th or 39th gestational week, all ECVs were performed during the 37th week. As ECV attempts are noted to become increasingly more difficult to perform later in gestation because of the growth of the fetus and a decreasing ratio of amniotic fluid volume to fetal size (8), immediately repeating ECV attempts was most likely beneficial.
Third, the use of uterine tocolytics may be important when reattempting ECVs. In contrast to the two previous reports (3,4), terbutaline was readministered in our study before the ECV trial with neuraxial blockade, and in most of the cases, uterine tocolysis was augmented with nitroglycerin. Although the need for and the effects of uterine tocolytics on ECV success rates remain controversial, the most current ECV practice bulletin published by the American College of Obstetricians and Gynecologists (7) and a recent review of randomized and quasi-randomized trials support their use (11). Recent experience with nitroglycerin as a uterine relaxant has also been observed (12) and its use has been associated with ECV success in a limited study (13). Our results appear to support its use, as 6 of 8 patients who received nitroglycerin had successful ECV attempts. No adverse effects were noted with the use of nitroglycerin. The independent effect of augmentation of tocolysis with nitroglycerin in the setting of ECV deserves further analysis.
The relative safety and benefit of performing ECV reattempts with anesthesia was corroborated by our findings. The single case of persistent bradycardia resulting in an urgent cesarean delivery used the epidural catheter placed for the ECV attempt and good neonatal and maternal outcomes were realized. In addition, successful versions occurred in the majority of patients; 87% of parturients reattempting an ECV with the use of central neuraxial blockade underwent a successful version, of which 62% ultimately resulted in a vaginal delivery. The improvement in quality of life after a vaginal delivery should be incorporated into cost-benefit analyses of the ECV technique with anesthesia (4). The results indicate that the use of central neuraxial anesthesia enhances the success of failed ECV attempts; however, as only those parturients who consented to a reattempt potentially benefited, the use of such techniques is perhaps most optimally applied for initial ECV attempts, as noted by Birnbach et al. (6) and others. Whether used for initial or failed ECV attempts, consideration for the use of a combined spinal epidural technique with a short-acting intrathecal local anesthetic should be given. The short anesthetic duration would allow for the option of a timely discharge in the event of a successful version, and should success or failure mandate a trial of labor or an operative delivery, the epidural catheter could allow additional analgesia or anesthesia to be administered.
In conclusion, epidural and spinal anesthesia can increase the success rate of previously failed ECV attempts. Additional factors that should be considered are immediately reattempting the ECV, providing uterine tocolysis with pharmacologic drugs, and, when possible, using an obstetrician experienced with ECV techniques.
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References |
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TopAbstractIntroductionMethodsResultsDiscussionReferences |
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- Hannah ME, Hannah WJ, Hewson SA, et al. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Lancet 2000; 356: 1375–83.[Web of Science][Medline]
- Sanchez-Ramos L, Wells TL, Adair CD, et al. Route of breech delivery and maternal and neonatal outcomes. Int J Gynaecol Obstet 2001; 73: 7–14.[Medline]
- Neiger R, Hennessy MD, Patel M. Reattempting failed external cephalic version under epidural anesthesia. Am J Obstet Gynecol 1998; 179: 1136–9.[Web of Science][Medline]
- Rozenberg P, Goffinet F, de Spirlet M, et al. External cephalic version with epidural anaesthesia after failure of a first trial with beta-mimetics. BJOG 2000; 107: 406–10.[Medline]
- Dugoff L, Stamm CA, Jones OW 3rd, et al. The effect of spinal anesthesia on the success rate of external cephalic version: a randomized trial. Obstet Gynecol 1999; 93: 345–9.[Web of Science][Medline]
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Birnbach DJ, Matut J, Stein DJ, et al. The effect of intrathecal analgesia on the success of external cephalic version. Anesth Analg 2001; 93: 410–3.
[Abstract/Free Full Text] - ACOG Practice Bulletin Number 13. External cephalic version. Washington, DC: American College of Obstetricians and Gynecologists, February 2000.
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Carlan SJ, Dent JM, Huckaby T, et al. The effect of epidural anesthesia on safety and success of external cephalic version at term. Anesth Analg 1994; 79: 525–8.
[Abstract/Free Full Text] - Manusco KM, Yancey MK, Murphy JA, Markenson GR. Epidural analgesia for cephalic version: a randomized trial. Obstet Gynecol 2000; 95: 648–51.[Web of Science][Medline]
- Teoh TG. Effect of learning curve on the outcome of external cephalic version. Singapore Med J 1997; 38: 323–5.[Medline]
- Hofmeyr GJ. External cephalic version facilitation for breech presentation at term. Cochrane Database Syst Rev 2000; 2: CD000184.
- Caponas G. Glyceryl trinitrate and acute uterine relaxation: a literature review. Anaesth Intensive Care 2001; 29: 163–77.[Web of Science][Medline]
- Yanny H, Johanson R, Balwin KJ, et al. Double-blind randomised controlled trial of glyceryl trinitrate spray for external cephalic version. BJOG 2000; 107: 562–4.[Medline]
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