Transcutaneous electrical nerve stimulation (TENS) for pain management in labour

 

Abstract

Background

Transcutaneous nerve stimulation (TENS) has been proposed as a means of reducing pain in labour. The TENS unit emits low-voltage electrical impulses which vary in frequency and intensity. During labour, TENS electrodes are generally placed on the lower back, although TENS may be used to stimulate acupuncture points or other parts of the body. The physiological mechanisms whereby TENS relieves pain are uncertain. TENS machines are frequently operated by women, which may increase a sense of control in labour.

Objectives

To assess the effects of TENS on pain in labour.

Search methods

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2011) and reference lists of retrieved papers.

Selection criteria

Randomised controlled trials comparing women receiving TENS for pain management in labour versus routine care, alternative non-pharmacological methods of pain relief, or placebo devices. We included all types of TENS machines.

Data collection and analysis

Two review authors assessed for inclusion all trials identified by the search strategy, carried out data extraction and assessed risk of bias. We have recorded reasons for excluding studies.

Main results

Seventeen trials with 1466 women contribute data to the review. Thirteen examined TENS applied to the back, two to acupuncture points, and two to the cranium. Overall, there was little difference in pain ratings between TENS and control groups, although women receiving TENS to acupuncture points were less likely to report severe pain (average risk ratio 0.41, 95% confidence interval 0.31 to 0.54; measured in two studies). The majority of women using TENS said they would be willing to use it again in a future labour. Where TENS was used as an adjunct to epidural analgesia there was no evidence that it reduced pain. There was no consistent evidence that TENS had any impact on interventions and outcomes in labour. There was little information on outcomes for mothers and babies. No adverse events were reported.

Authors' conclusions

There is only limited evidence that TENS reduces pain in labour and it does not seem to have any impact (either positive or negative) on other outcomes for mothers or babies. The use of TENS at home in early labour has not been evaluated. TENS is widely available in hospital settings and women should have the choice of using it in labour.

 

Plain language summary

TENS (transcutaneous nerve stimulation) for pain relief in labour

TENS is a device that emits low-voltage currents and which has been used for pain relief in labour. The way that TENS works is not well understood. The electrical pulses are thought to stimulate nerve pathways in the spinal cord which block the transmission of pain. In labour the electrodes from the TENS machine are usually attached to the lower back (and women themselves control the electrical currents using a hand-held device) but TENS can also be applied to acupuncture points or directly to the head. The purpose of the review was to see whether TENS is effective in relieving pain in labour. The review includes results from 17 studies with a total of 1466 women. Thirteen studies examined TENS applied to the back, two to acupuncture points and two to the cranium (head). Results show that pain scores were similar in women using TENS and in control groups. There was some evidence that women using TENS were less likely to rate their pain as severe but results were not consistent. Many women said they would be willing to use TENS again in a future labour. TENS did not seem have an effect on the length of labour, interventions in labour, or the well-being of mothers and babies. It is not known whether TENS would help women to manage pain at home in early labour. Although it is not clear that it reduces pain, women should have the choice of using TENS in labour if they think it will be helpful.

 

摘要

背景

經皮神經電刺激應用於生產時減痛治療

經皮神經電刺激被已視為生產時減痛治療的一種方式。經皮神經電刺激器是可以發出不同頻和強度的低壓電脈衝，儀器的電極可以放在針灸的穴位或身體的其他部位，在生產時通常是貼在產婦的下背部。經皮神經電刺激可以減輕疼痛的生理機轉還不清楚，在應用時，由產婦自己控制儀器，便於調整強度減輕疼痛。

目標

評估經皮神經電刺激在生產時減輕疼痛的作用。

搜尋策略

我們搜尋Cochrane Pregnancy and Childbirth Group's Trials Register (November 2008)。

選擇標準

選擇比較生產時應用經皮神經電刺激減輕疼痛與常規照護、其他藥物止痛或應用安慰裝置的隨機對照試驗，試驗中應用的經皮神經電刺激不限型號。

資料收集與分析

由2位回顧作者根據搜尋策略評估可納入的試驗，進行資料摘錄及偏差風險分析，我們並且記錄其它試驗被排除的原因。

主要結論

搜尋發現25篇的試驗，我們排除6篇，納入19篇對1671位孕婦的試驗。其中15篇試驗的經皮神經電刺激電極置於孕婦的背部，2篇試驗的電極置於針灸穴位，另外2篇的電極置於頭部。整體而言，經皮神經電刺激電極置於針灸穴位的孕婦較少出現嚴重疼痛(risk ratio 0.41, 95% confidence interval 0.32 to 0.55)，但使用經皮神經電刺激器組比較對照組在疼痛排序少有差異。使用經皮神經電刺激的孕婦多數表示在下一次生產時有意願再次使用。如果經皮神經電刺激作為硬膜外麻醉的輔助治療，並未顯示其在減痛上的效益。相關的試驗結果顯示，在生產時使用經皮神經電刺激，對其它介入性治療方式的需求及生產結果的影響沒有一致的結論。有關母嬰狀況的資料很少,也沒有副作用的報告。

作者結論

使用經皮神經電刺激對減輕孕婦疼痛的證據有限，對母嬰健康似乎沒有影響(不論是正面或負面的影響)。 尚未有試驗評估初期產程時在家使用經皮神經電刺激的影響。然而在醫院生產時，孕婦可以選擇使用。

翻譯人

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

總結

經皮神經電刺激是一種釋放低壓脈衝的儀器，可用於生產時的減痛治療。經皮神經電刺激緩解疼痛的機轉未完全瞭解，有可能是電刺激作用在脊髓神經通路，阻斷了疼痛感覺的傳遞。生產時，經皮神經電刺激儀器的電極置於孕婦的下背部(由孕婦自己用手持裝置控制)，也可用在針灸穴位或頭部。此次回顧目標為探討經皮神經電刺激減輕產痛的效益。回顧納入了19篇包含1671位孕婦的試驗，15篇試驗的經皮神經電刺激電極置於孕婦的背部，2篇試驗的電極置於針灸穴位，另外2篇的置於頭部。結果顯示，使用經皮神經電刺激器組和對照組的疼痛分數相似，有一些證據認為使用經皮神經電刺激的孕婦較少出現嚴重疼痛感覺，但結果缺乏一致性。使用經皮神經電刺激的孕婦多數有下次生產再次使用的意願。使用經皮神經電刺激對產程的長短、其它介入性治療方式的需求及母嬰健康似乎沒有影響。現在還不知道使用經皮神經電刺激，對孕婦在家中控制早期產程疼痛是否有幫助。雖然經皮神經電刺激用於減輕疼痛的機理還不清楚，但如果孕婦認為它有助於減輕疼痛就可以在生產時使用。