New RCT into alternatives to pethidine during childbirth may reduce epidurals

Dr Matt Wilson

The largest randomised trial of its kind, lead by ScHARR's Dr Matt Wilson (Chief Investigator) explored the use of Remifentanil as an alternative to Pethidine. Their research was funded by a NIHR Clinician Scientist Fellowship, RESPITE and involved 401 women at 14 UK hospitals between May 2014 and September 2016.

The publication will be accompanied by a commissioned Editorial and a Lancet podcast, generated from an interview with Dr Wilson.

Pethidine is a drug for pain relief, routinely given to around a third of the 750,000 women who give birth per year in the UK and thousands more worldwide. It is administered via an injection into muscle. While pethidine is commonly used in labour, its effectiveness in providing pain relief has long been challenged and it has serious, known side effects which include maternal nausea and sedation; it is also transferred to the baby, via the placenta producing unwanted effects. 

Remifentanil, a new short-acting opioid pain-killer, given by "Patient Controlled Analgesia" (PCA) is self-administered, through a drip, by women in labour with a handheld device, to give pain relief that coincides with contractions. It is currently offered as standard care in only very few UK hospitals.

The largest randomised trial of its kind, lead by Dr Matt Wilson (Chief Investigator) funded by a NIHR Clinician Scientist Fellowship, RESPITE involved 401 women at 14 UK hospitals between May 2014 and September 2016.

The results of the trial, published in The Lancet today, 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 200 women who were given pethidine, 81 (41 per cent) went on to have an epidural, compared to just 39 (19 percent) of the 201 women who were given remifentanil PCA.

Prior to RESPITE, 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 result in women suffering further long-term health complications and a longer stay in hospital after birth. Women receiving remifentanil in the study had a lower instrumental delivery rate than the pethidine group.

The study showed that remifentanil is safe, when given under correct supervision. More women required extra oxygen during their labour with remifentanil, but there was no difference in the sedation or depression of breathing between groups. There was also no difference in the health of babies born to women who received remifentanil compared to usual care.

The trial also found that the average pain score women reported during their labour (on a scale of 0 to 100) was significantly lower in the remifentanil PCA group, and that women’s satisfaction with their pain relief and its effectiveness was significantly higher with remifentanil PCA group compared to the pethidine.

With the evidence generated by the study, the researchers now hope to see a change in national clinical guidelines, to incorporate the routine use of remifentanil PCA for labour and an important increase in maternal choice.

Click here for a Lancet commentary on the research, and click here for full text of the Lancet publication on the RESPITE trial.