Wednesday, October 25, 2006

Epidurals: the quality of the evidence

Drs. Murphy and Fullerton have created a new instrument to analyze childbirth. It is called an Optimality Index. Rather than looking at adverse outcomes, Murphy and Fullerton believe that childbirth can best be analyzed by comparing individual outcomes with optimal outcomes. The prefer this approach because it deliberately incorporates specific beliefs about what constitutes optimal care. For example, traditional medical studies would consider the birth of a healthy baby to a healthy mother the optimal outcome; the Optimality Index would subtract points from a perfect score because, in their view, having an epidural is a non-optimal outcome.

Murphy and Fullerton claim that their choices of optimal vs. non-optimal practices are grounded in scientific research, and are not arbitrary designations. Therefore, they provide multiple studies to substantiate their claims about optimality. It is quite instructive to review the claims and documentation about epidurals.

Not surprisingly, Murphy and Fullerton have concluded that merely having an epidural is a "non-optimal" factor in any labor. They seek to buttress this assertion with no less than 8 separate studies about epidurals. All of the articles are relatively recent, and I assume that Murphy and Fullerton believe that these are the best, most current studies that document non-optimal effects of epidurals. Below I have listed each article and the abstract or conclusion, so you can look at them individually. Let's look at the studies that supposedly show that merely having an epidural, in and of itself is a "non-optimal" factor.

In summary:

None of the studies show an increase in neonatal mortality.

None of the studies show an increase in neonatal morbidity.

None of the studies show an increase in maternal mortality.

None of the studies show an increase in C-section rate.

All the studies showed epidurals to be extremely effective for pain relief.

The one study that specifically addressed neonatal outcomes concluded that "although epidural analgesia may cause maternal hypotension and fever, longer second stage of labour and more instrumental vaginal deliveries, these potentially adverse factors appear to be outweighed by benefits to neonatal acid-base status."

The study cited to show an adverse impact of epidurals on breastfeeding, showed an association, but concluded that prospective studies would be needed to show if there is a causal relationship.

The study cited to show the long term effects of epidurals found no difference in long term side effects between women who received epidurals and those who did not.

Two studies showed that epidurals might increase the length of the first stage of labor.

Three studies showed that epidurals increase the length of the second stage of labor and increase the number of forceps deliveries.

That's it. That's all there is. Murphy and Fullerton claim that merely having an epidural is "non-optimal" despite the fact that there is no increase in neonatal mortality or morbidity, no increase in maternal mortality, no increase in the C-section rate, no evidence of relationship bewteen epidurals and breastfeeding, and no long term side effects for the mother.

The only thing that these studies show is that epidurals can increase the length of labor and can increase the rate of forceps deliveries.

So epidurals provide safe and effective pain relief in labor. They have no short term or long term impact on the baby. They also have no short term or long term impact on MOST women (only a minority experienced longer labors or forceps deliveries). Why, then, do they conclude that merely having an epidural is a "non-optimal" outcome?

I believe that this conclusion reflects their prejudice that any intervention in labor, even one requested by the mother and found very effective by the mother, is wrong. They are certainly entitled to their opinion, but it is very important to realize that it is only their OPINION. At least when it comes to epidurals, the index does not tell us whether someone had a birth that SHE judged to be optimal. Evidently, HER opinion does not count. It only tells us whether she had a birth that Murphy and Fullerton approve of. If the epidural information is any guide, this is an index that evaluates whether a woman has conformed to the socially constructed notion of what an "optimal" birth should be; in other words, yet another way for natural childbirth advocates to judge other women.


Labor course and delivery in epidural analgesia: a case-control
. Decca L, Daldoss C, Fratelli N, Lojacono A, Slompo M, Stegher C, Valcamonico A, Frusca T. J Matern Fetal Neonatal Med. 2004;16(2):115-8.

Our results confirm that epidural analgesia does not affect the rate of Cesarean delivery, while increasing the use of oxytocin augmentation, the duration of the second stage of labor and the rate of instrumental vaginal delivery.

Epidural versus non-epidural analgesia for pain relief in labour. Howell CJ. In: The Cochrane Database of Systematic Reviews, 2003.

Eleven studies involving 3157 women were included. Epidural analgesia was associated with greater pain relief than non-epidural methods, but also with longer first and second stages of labour, an increased incidence of fetal malposition, and increased use of oxytocin and instrumental vaginal deliveries. With new trial data included, no statistically significant effect on caesarean section rates could be identified. REVIEWER'S CONCLUSIONS: Epidural analgesia appears to be very effective in reducing pain during labour, although there appear to be some potentially adverse effects. Further research is needed to investigate adverse effects and to evaluate the different techniques used in epidural analgesia.

Randomised study of long term outcome after epidural versus non-epidural analgesia
during labor
. Howell CJ, Dean T, Lucking L, Dziedzic K, Jones, PW, Johanson RB. BMJ. 2002; 325(7360):357.

After childbirth there are no differences in the incidence of long term low back pain, disability, or movement restriction between women who receive epidural pain relief and women who receive other forms of pain relief.

Analgesic efficacy of intramuscular opioids versus epidural analgesia in labor. Jain S, Arya VK, Gopalan S, Jain V. Int J Gynaecol Obstet. 2003;83(1):19-27.

Ninety percent of women rated analgesia as good to excellent in the epidural group as compared with 72% of women in the meperidine group and 65% in tramadol group. However, epidural caused a significant prolongation of first (P<0.05) and second (P<0.01) stage of labor with an increased number of operative deliveries (27% in the epidural, 7.6% in the meperidine, and 11.4% in the tramadol groups, P<0.05). In the epidural group 40% women had urinary retention and 16% had motor weakness, whereas sedation was the only side effect seen in the meperidine (41%) and tramadol groups (9%). Respiratory depression was noted among three neonates in the meperidine group, two in the tramadol group and none in the epidural group. CONCLUSIONS: The analgesic efficacy and maternal satisfaction is better with epidural analgesia than with opioids. Analgesia provided by meperidine and tramadol is comparable and approximately 50% of women rated the analgesia as good. Meperidine is better in the second stage than tramadol. Hence in developing nations where availability of facilities is the main limiting factor, intramuscular opioids can be considered suitable alternatives.

Epidural analgesia for pain relief in labour and childbirth – a review with a systematic approach. Nystedt A.; Edvardsson D.; Willman A. Journal of Clinical 2004; 13:4, pp. 455-466.

A structured question was formulated and used for deriving search terms, establishing the inclusion of certain criteria and retrieving articles, i.e. what are the effects of epidural analgesia for pain relief in labour and childbirth?..
Twenty-four articles were retrieved and systematically assessed. Seven studies were judged as high quality, 15 as moderate quality and two as low quality. The majority of studies appraised in this review failed to obtain or establish a cause and effect relationship. According to the data, it seems clear that the use of epidural analgesia is considered to be an effective method of pain relief during labour and childbirth from the perspective of women giving birth.

Factors associated with a prolonged second state of labour--a case-controlled study of 364 nulliparous labours. Journal of Obstetrics & Gynaecology, 2003; 23:3. M O'Connell, J Hussain, F Maclennan, S Lindow.

The aim of the study is to identify factors associated with a second stage of labour greater than 2 hours in nulliparous women delivering at term. It a retrospective case-control study of 182 women with a second stage less than 2 hours' duration, matched with 182 women with a second stage greater than 2 hours. Women with a short second stage of labour were significantly younger (mean age 23.2 vs. 24.9 years) and had significantly smaller babies (mean weight 3315 g vs. 3463 g) than women with a long second stage. Long duration of the second stage of labour was significantly associated with oxytocin and epidural use. The intervention rate did not rise above 50% until the second stage exceeded 5 hours duration. The fetal outcome was good in both groups of patients.

Analgesia in labour and fetal acid–base balance: a meta-analysis comparing epidural with systemic opioid analgesia. BJOG, 2002; 109:1344. F Reynolds, S Sharma, P Seed.

Umbilical artery pH is influenced by maternal hyperventilation. Base excess is therefore a better index of metabolic acidosis after labour. Epidural analgesia is associated with improved neonatal acid–base status, suggesting that placental exchange is well preserved in association with maternal sympathetic blockade and good analgesia. Although epidural analgesia may cause maternal hypotension and fever, longer second stage of labour and more instrumental vaginal deliveries, these potentially adverse factors appear to be outweighed by benefits to neonatal acid–base status.

Breast-feeding problems after epidural analgesia for labour: a retrospective cohort study of pain, obstetrical procedures and breast-feeding practices. Volmanen P, Valanne J, Alahuhta S. Int J Obstet Anesth. 2004 Jan;13(1):25-9.

Various clinical practices have been found to be associated with breast-feeding problems. However, little is known about the effect of pain, obstetrical procedures and analgesia on breast-feeding behaviour... As many as 44% of the 99 mothers reported partial breast feeding or formula feeding during the first 12 weeks. Older age of the mother, use of epidural analgesia and the problem of "not having enough milk" were associated with the failure to breast-feed fully. Caesarean section, other methods of labour analgesia and other breast-feeding problems were not associated with partial breast feeding or formula feeding. In the sub-sample, 67% of the mothers who had laboured with epidural analgesia and 29% of the mothers who laboured without epidural analgesia reported partial breast feeding or formula feeding (P = 0.003). The problem of "not having enough milk" was more often reported by those who had had epidural analgesia. Further studies conducted prospectively are needed to establish whether a causal relationship exists between epidural analgesia and breast-feeding problems.


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