Intravenous remifentanil patient-controlled analgesia versus intramuscular pethidine for pain relief in labour (RESPITE) : an open-label, multicenter, randomized controlled trial

While pethidine (meperidine) is widely used for pain relief during labor, there are unfavorable side effects, such as nausea/vomiting, maternal sedation, and possible neonatal depression. In addition, more than a third of women receiving pethidine ultimately request epidural labor analgesia. Remifentanil is a potential alternative to pethidine for labor pain relief. Its rapid onset and short duration of action provide some benefits although its short duration requires administration via intravenous (IV) patient controlled analgesia (PCA). It is not commonly used in maternity units in the United Kingdom, however, as previous trials evaluating remifentanil versus pethidine yielded low-quality evidence. Stronger evidence was required to evaluate the efficacy and safety of remifentanil as compared with pethidine for labor pain management. The RESPITE trial primary outcome compared IV remifentanil PCA with intramuscular pethidine looking at the need to convert to epidural analgesia with secondary outcomes evaluating visual analog scale (VAS) pain scores, mode of delivery and adverse maternal or neonatal outcomes.