Pregnancy health centre

Is patient-controlled pain relief better during labour?

BMJ Group News

Women use less pain medicine during labour if they control their own dose, reports a new study on patient-controlled epidurals. This type of pain relief may also slightly lower a woman's risk of needing instruments to help deliver her baby.

What do we know already?

Epidurals are often used to minimise a woman's pain and discomfort during labour. A small tube is put into the woman's back to infuse pain medicine into her spine, numbing the lower half of her body. A constant level of pain medicine is usually provided, which the doctor can increase if need be. This is called a continuous epidural infusion.

However, a newer approach - called patient-controlled epidural analgesia - allows the woman to control her dose of pain medicine by pushing a button to give herself medicine when she needs it, up to a maximum dose. This way, a woman can modify her dose in response to her pain and stage of labour. Some women, for example, may prefer not to be as numb in the second stage of labour, as this may make it easier to push the baby out.

Several studies have also suggested other benefits with patient-controlled epidurals, including a drop in how much pain medicine women use and a shorter labour. Now, researchers have done a larger, good-quality study to put such benefits to the test.

They recruited 270 first-time mothers and randomly assigned them to three groups. One had continuous epidural infusions (CEIs), another had CEIs but were also able to increase their dose by pushing a button (patient-controlled epidural analgesia [PCEA]), and the third had PCEA only.

What does the new study say?

Women who had patient-controlled epidural analgesia on its own used 30 percent less pain medicine, on average, than women in the continuous infusion group, and 45 percent less than women in the combined group. Pain during the pushing stage was worse in the PCEA-only group. Even so, women in all three groups reported similar levels of satisfaction with their pain relief.

The researchers also didn't find any differences among the groups in how long the women's labours lasted and their chances of needing an operation to deliver their baby (a caesarean section). However, they did find that women in the PCEA-only group were slightly less likely to need ventouse or forceps to help deliver their baby.

How reliable are the findings?

This study hasn't yet been published in a medical journal, but was instead presented at a medical conference by the researchers. Because of this, we've not been able to look in detail at how the study was done, or at its results. This makes it hard to say for certain how reliable the findings are.

However, we do know that this was a randomised controlled trial, which is the best type of study for comparing treatments. The study was also 'double-blind', which means that neither the women nor their doctors knew which type of pain relief they were being given. (The researchers accomplished this by giving all the women buttons to push.) This strengthens the study's findings, by minimising the effect that people's expectations might have had on the results.