Alternative patient-controlled pain relief drug could significantly reduce the number of epidurals

16th August 2018

Largest and most rigorous trial of its kind compared two drugs given for pain control in labour - pethidine and remifentanil Half the number of women in the Remifentanil Patient Controlled Analgesia (PCA) group went on to require an epidural, compared to those in the pethidine group Remifentanil (PCA) is currently offered as standard care in very few UK hospitals but could significantly reduce the number of women requiring an epidural An alternative patient-controlled pain relief drug could significantly reduce the number of women requiring an epidural during childbirth, a new study has revealed.

The trial, led by a researcher from the University of Sheffield, compared two drugs given for pain control in labour pethidine and remifentanil. Women in established labour were randomly assigned one of the two pain killers and researchers then assessed how many of these women later went on to require an epidural. Pethidine is a drug for pain relief routinely given to around a third of the 750,000 women who give birth in the UK per year and is administered via an injection into a muscle. Remifentanil Patient Controlled Analgesia (PCA), which is delivered through a drip that women can control with a handheld device to give pain relief that coincides with their contractions, is currently offered as standard care in very few UK hospitals. The results published today (13 August 2018) in The Lancet, show that half the number of women in the remifentanil PCA group went on to require an epidural, compared to the pethidine group. Of the 199 women who were allocated pethidine, 41 per cent (81) went on to have an epidural, compared to just 19 percent (39) of the 201 women in the remifentanil PCA group. The RESPITE trial is the largest and most rigorous randomised trial of its kind involving 400 women who gave birth at 14 hospitals between May 2014 and September 2016. The study was conducted by researchers at the Universities of Sheffield, Birmingham and Nottingham, coordinated by Birmingham Clinical Trials Unit and funded by the National Institute of Health Research (NIHR). Chief Investigator, Dr Matthew Wilson of the University of Sheffield's School of Health and Related Research (ScHARR), said: -While pethidine is commonly used in labour, it does not provide effective pain relief for many women and has unwanted side effects including sedation and nausea. It can also transfer to the baby via the placenta. -Prior to our research it was already known that around a third of women who receive pethidine go on to have an epidural due to inadequate pain relief. -While epidurals provide highly effective pain relief, they lead to a higher rate of births involving the use of instruments such as forceps or suction, which can lead to women suffering further long-term health complications, such as incontinence or sexual dysfunction and needing a longer stay in hospital after birth. The trial found that the average pain scores women reported during their labour, were significantly lower in the remifentanil PCA group, and that women's satisfaction with their pain relief and its effectiveness was significantly higher with remifentanil compared to the pethidine. Dr Wilson added: -Our study has shown that remifentanil PCA is safe when given under correct supervision. More women required extra oxygen during their labour with remifentanil PCA, which needs to be clarified by further studies, but there was no difference in the sedation that women experienced or in the health of babies born to women who received remifentanil PCA, which was very reassuring. -RESPITE was designed to examine if there was a more effective alternative to pethidine which is safe, easy to administer and could ultimately reduce the number of women who have an epidural. -The results of the trial provide strong evidence that remifentanil PCA should be routinely offered as an alternative to pethidine and should be rolled out at hospitals across the UK. -Not only would it provide women with a more effective pain relief option in labour, it could significantly reduce the number of epidurals and the associated higher rates of instrumental births, in turn potentially reducing the financial burden on the NHS. The researchers now hope to see a change in national clinical guidelines toward more routine availability of remifentanil PCA to women in childbirth.