Epidural versus non-epidural or no analgesia in labour

 

Abstract

Background

Epidural analgesia is a central nerve block technique achieved by injection of a local anaesthetic close to the nerves that transmit pain and is widely used as a form of pain relief in labour. However, there are concerns regarding unintended adverse effects on the mother and infant.

Objectives

To assess the effects of all modalities of epidural analgesia (including combined-spinal-epidural) on the mother and the baby, when compared with non-epidural or no pain relief during labour.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2011).

Selection criteria

Randomised controlled trials comparing all modalities of epidural with any form of pain relief not involving regional blockade, or no pain relief in labour.

Data collection and analysis

Two of the review authors independently assessed trials for eligibility, methodological quality and extracted all data. We entered data into RevMan and double checked it for accuracy. Primary analysis was by intention to treat; we conducted subgroup and sensitivity analyses where substantial heterogeneity was evident.

Main results

We included 38 studies involving 9658 women; all but five studies compared epidural analgesia with opiates. Epidural analgesia was found to offer better pain relief (mean difference (MD) -3.36, 95% confidence interval (CI) -5.41 to -1.31, three trials, 1166 women); a reduction in the need for additional pain relief (risk ratio (RR) 0.05, 95% CI 0.02 to 0.17, 15 trials, 6019 women); a reduced risk of acidosis (RR 0.80, 95% CI 0.68 to 0.94, seven trials, 3643 women); and a reduced risk of naloxone administration (RR 0.15, 95% CI 0.10 to 0.23, 10 trials, 2645 women). However, epidural analgesia was associated with an increased risk of assisted vaginal birth (RR 1.42, 95% CI 1.28 to 1.57, 23 trials, 7935 women), maternal hypotension (RR 18.23, 95% CI 5.09 to 65.35, eight trials, 2789 women), motor-blockade (RR 31.67, 95% CI 4.33 to 231.51, three trials, 322 women), maternal fever (RR 3.34, 95% CI 2.63 to 4.23, six trials, 2741 women), urinary retention (RR 17.05, 95% CI 4.82 to 60.39, three trials, 283 women), longer second stage of labour (MD 13.66 minutes, 95% CI 6.67 to 20.66, 13 trials, 4233 women), oxytocin administration (RR 1.19, 95% CI 1.03 to 1.39, 13 trials, 5815 women) and an increased risk of caesarean section for fetal distress (RR 1.43, 95% CI 1.03 to 1.97, 11 trials, 4816 women). There was no evidence of a significant difference in the risk of caesarean section overall (RR 1.10, 95% CI 0.97 to 1.25, 27 trials, 8417 women), long-term backache (RR 0.96, 95% CI 0.86 to 1.07, three trials, 1806 women), Apgar score less than seven at five minutes (RR 0.80, 95% CI 0.54 to 1.20, 18 trials, 6898 women), and maternal satisfaction with pain relief (RR 1.31, 95% CI 0.84 to 2.05, seven trials, 2929 women). We found substantial heterogeneity for the following outcomes: pain relief; maternal satisfaction; need for additional means of pain relief; length of second stage of labour; and oxytocin augmentation. This could not be explained by subgroup or sensitivity analyses, where data allowed analysis. No studies reported on rare but potentially serious adverse effects of epidural analgesia.

Authors' conclusions

Epidural analgesia appears to be effective in reducing pain during labour. However, women who use this form of pain relief are at increased risk of having an instrumental delivery. Epidural analgesia had no statistically significant impact on the risk of caesarean section, maternal satisfaction with pain relief and long-term backache and did not appear to have an immediate effect on neonatal status as determined by Apgar scores. Further research may be helpful to evaluate rare but potentially severe adverse effects of epidural analgesia on women in labour and long-term neonatal outcomes.

 

Plain language summary

Epidurals for pain relief in labour

Pain relief is important for women in labour. Pharmacological methods of pain relief include inhalation of nitrous oxide, injection of opioids and regional analgesia with an epidural for a central nerve block. Epidurals are widely used for pain relief in labour and involve an injection of a local anaesthetic into the lower region of the spine close to the nerves that transmit pain. Epidural solutions are given by bolus injection, continuous infusion or using a patient-controlled pump. Lower concentrations of local anaesthetic are needed when they are given together with an opiate, allowing women to maintain the ability to move around during labour and to bear down. Epidural analgesia may sometimes give inadequate analgesia, which may be due to non-uniform spread of local anaesthetic. Combined spinal-epidural involves a single injection of local anaesthetic or opiate into the cerebral spinal fluid for fast onset of pain relief as well as insertion of the epidural catheter for continuing pain relief. Side effects such as itchiness, drowsiness, shivering and fever have been reported and rare but potentially severe adverse effects of epidural analgesia do occur.

The review identified 38 randomised controlled studies involving 9658 women. All but five studies compared epidural analgesia with opiates. Epidurals relieved labour pain better than other types of pain medication but led to more use of instruments to assist with the birth. Caesarean delivery rates did not differ overall and nor were there effects of the epidural on the baby soon after birth; fewer babies needed a drug (naloxone) to counter opiate use by the mother for pain relief. The risk of caesarean section for fetal distress was increased. Women who used epidurals were more likely to have a longer delivery (second stage of labour), needed their labour contractions stimulated with oxytocin, experienced very low blood pressure, were unable to move for a period of time after the birth (motor blockage), had problems passing urine (fluid retention) and suffered fever. Long-term backache was no different. Further research on reducing the adverse outcomes with epidurals would be helpful.

 

摘要

背景

待產過程中使用硬腦膜外麻醉vs非硬腦膜外麻醉、或不麻醉的比較

硬腦膜外麻醉，就是將局部麻醉藥品注射於中樞神經主司痛覺傳導神經的附近，藉此阻斷痛覺而被廣泛用來減輕產痛。至於是否對母親或胎兒造成影響，則有待評估。

目標

待產過程中，評估使用各種形式的硬腦膜外麻醉(包括併用脊髓麻醉)，與非硬腦膜外麻醉、或不麻醉，對母親與胎兒的影響. 。

搜尋策略

搜尋範圍 “The Cochrane Pregnancy and Childbirth Group Trials Register (June 2005)” 。

選擇標準

隨機取樣來比較待產過程中，使用各種形式的硬腦膜外麻醉，與其他任何非局部麻醉，或不麻醉的效果。

資料收集與分析

兩位作者獨立評估這些試驗的合格取樣標準、操作品質，並選取所有數據。把數據輸入RevMan系統，並接受雙重檢驗。初步分析都選擇自願接受麻醉者; 敏感度分析，排除取樣中大於30% 非分配性處置的試驗。

主要結論

21篇文獻的樣本數為6664名婦女，其中只有一篇拿鴉片來比較硬腦膜外麻醉的效果．基於技術上的理由，僅選到一篇婦女在待產過程中，感覺使用硬腦膜外麻醉比非硬腦膜外麻醉有效者(weighted mean difference (WMD) −2.60, 95% confidence interval (CI) −3.82 t 1.38,一篇文獻,105位婦女樣本數)。不過，使用硬腦膜外麻醉會增加產械式陰道生產的風險(relative risk (RR) 1.38, 95% CI 1.2 to 1.53,17篇文獻,6162位婦女樣本數)。另外，使用硬腦膜外麻醉，並不會影響剖腹生產率(RR 1.07, 95% CI 0.93 to 1.23,20篇文獻,6534位婦女樣本數)長期背痛(R .00, 95% CI 0.89 to 1.12,2 篇文獻,814位婦女樣本數),五分鐘Apgar score低分者(RR 0.70, 95% CI 0.44 to 1.10,14篇文獻,5363位婦女樣本數),與婦女滿意度(RR 1.18 95% I 0.92 to 1.50,5篇文獻,1940位婦女樣本數)等風險。並沒有文獻提及硬腦膜外麻醉會引起任何罕見但嚴重的副作用。

作者結論

硬腦膜外麻醉是減輕產痛的有效方法。但也可能因此而增加產械式陰道生產的風險. 硬腦膜外麻醉不會影響剖腹生產率、婦女滿意度、長期背痛、與新生兒出生後的立即狀況(Apgar score評估值)。至於硬腦膜外麻醉是否會造成待產婦女罕見但嚴重的副作用，及不利於新生兒長期的結果，則有待更多的研究來評估。

翻譯人

本摘要由周產期醫學會(Taiwan Society of Perinatology)郭鐘海翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

硬腦膜外麻醉被廣泛用來減輕產痛。有許多不同的方式，但都要從下背部注射。本文認為硬腦膜外麻醉，較其他麻醉藥來的有效，但會增加產械式陰道生產的風險。硬腦膜外麻醉不會影響剖腹生產率、婦女滿意度、長期背痛、與新生兒出生後的立即狀況。不過硬腦膜外麻醉可能造成第二產程延長，需要加用催產藥物、血壓降低、產後一段時間無法活動、解尿困難與發燒等狀況。進一步減少硬腦膜外麻醉引發不良反應的研究，對硬腦膜外麻醉的應用會有幫助。