Inhaled pain relief is a safe and effective option in early labour

by Bruce Sylvester – Following a systematic review of 26 relevant studies involving 2,959 women, Cochrane Review researchers concluded that inhaled pain relief appears to offer safe and effective pain relief during the first stage of labour.

“We need to apply some caution to these findings as there was a lot of variation in the analyses of pain intensity and of pain relief between the studies and some of the trials involved small numbers of women,” said lead author Trudy Klomp, MSc, of the Department of Midwifery Science and the EMGO Institute for Health and Care Research at VU University Medical Center, Amsterdam. “But despite these limitations, inhaled analgesia’s ability to significantly reduce pain intensity and increase pain relief indicates that it can help women in labour, particularly those who want pain relief but do not want more intensive forms such as epidurals.”

The findings were published on Sept 11 in The Cochrane Library.

As background, the authors noted that many women want a choice in pain relief in labour and many women want to avoid invasive pain management. Inhaled oxygen plus either a flurane derivative or nitrous oxide reduces pain and allows the patient remain awake and to swallow. Also this kind of pain relief can be administered in less than a minute, taking effect within a minute.

The reviewers found that nitrous oxide alone had an analgesic effect but with side effects such as nausea, vomiting, dizziness and drowsiness. They found that adding fluranes gave a more powerful treatment effect to nitrous oxide and reduced side effects.

They noted that while nitrous oxide can be administered by midwives, fluranes can be administered only under supervision by a trained anaesthesia professional. “This is probably the main reason why flurane use is not widespread and also why little research is done on this form of inhaled analgesia for the management of labour pain,” said Klomp.

The researchers concluded that wider use of nitrous oxide could help many women who currently have no effective option for pain relief, and, where appropriately trained anaesthesia professionals are available, an increase in the use of flurane.