High dose versus low dose opioid epidural regimens for pain relief in labour

  1. To compare the effects (see outcomes below) of different total* doses (in terms of boluses, concentration, volume and timeframe) of opioid epidural (excluding combined-spinal epidural and intrathecal) analgesia administered (alone or as adjunctive) during labour on the woman and the infant.
  2. To compare the safety (see outcomes below) of different total* doses (as above) of opioid epidural analgesia administered during labour for the woman and the infant.

*We define ‘total’ as the sum of all boluses and infusions (concentration, volume and timeframe) administered between onset of labour (as defined by authors) and delivery. If analgesia post-delivery is reported, we shall describe this separately.

We shall undertake secondary analyses of drug concentrations and volumes, see Types of interventions. However, since opioids pass into the fetus, and may accumulate, total dose is an important consideration for infant adverse events, such as drowsiness. (see Why it is important to do this review).

This is a protocol.