Traditional analgesic agents: are parenteral narcotics passé and do inhalational agents still have a place in labour?

Abstract

Systemic labour pain treatment with opioids and inhaled nitrous oxide has for many decades frequently been used in medically developed countries. Self-administered nitrous oxide (50% in oxygen) has never gained the same popularity in the USA as in the UK or Scandinavia but the use of opioids, mainly pethidine, has generally been widespread in spite of well-known negative effects on the postnatal adaptation of the newborn. Since the often very intense labour pain seems to respond very poorly even to highly sedating doses of parenteral opioids, their frequent use during delivery and parturition has to be questioned. Self-administered inhalation of nitrous oxide 50% in oxygen also has a limited efficacy for relieving labour pain but because it is mainly devoid of adverse effects on the baby or on the parturient its future use in obstetrics can be defended more easily, either as a sole agent in women with low labour pain scores or in early labour preceding epidural analgesia.