Pain Relief and Progress of Labour With Remifentanil Patient-controlled Analgesia Versus Combined Spinal-epidural Analgesia in Multiparous Women: a Prospective Observational Study

Introduction:

Neuraxial analgesia is considered the most effective method of pain relief during labor. When unavailable, contraindicated, refused by parturient or discouraged by midwife/obstetrician, alternative methods of analgesia are required which should to be effective, without major side effects and flexible enough to adapt to variable analgesic requirements during labor.

Remifentanil may be an ideal drug for labor analgesia due to its pharmacodynamic and pharmacokinetic profile. It is an ultra-short-acting µ1-opioid receptor agonist, rapidly metabolized by plasma and tissue esterases. It has onset time of 30 to 60 seconds and a peak effect at 2,5 min. It rapidly crosses the placenta and it is quickly metabolized by the fetus. Several studies which compared remifentanil patient controlled analgesia (PCA) with epidural analgesia in nulliparous patients or parturient of mixed parity have demonstrated a lower analgesic efficacy of remifentanil. Remifentanil, as compared to epidural analgesia, showed a satisfactory for pain relief only at the beginning of labor with a gradual elevation of pain scores as labor progressed. However, the fast onset and limited time efficacy may render it useful in multiparous with a faster labor progression, thus even making it an alternative to single-shot spinal analgesia.

The anaesthetic technique may also affect the progress of labor. A combined spinal-epidural analgesia (CSEA) has been demonstrated to be associated with a greater cervical dilation relative to conventional epidural analgesia in nulliparous patients. There are no data on labour progression difference as compared to remifentanil PCA in multiparous.

We therefore conduct the study in multiparous patients to compare remifentanil PCA and CSEA with respect to pain relief and the progress of labor.