In 2002, a study by Vyveret al showed that labour epidurals were commonly administered as either a continuous epidural infusion analgesia (CEI) or patient-controlled epidural analgesia (PCEA). Unfortunately, not all pregnant mothers are suitable for epidural analgesia. In order to overcome this problem, opioid-based analgesics such as pethidine and fentanyl were used as an alternative to labour epidural. However, older generations of opioids showed profound side effects on the mother such as sedation, respiratory depression, nausea, vomiting and itchiness while the newborn may have respiratory depression.

The use of remifentanil in obstetric started in 1998 after an initial study established its pharmacokinetic profile in pregnant patients and neonates. Pharmacokinetic and pharmacodynamic properties of remifentanil makes it a safe alternative to epidural analgesia.

In view of the above, we designed our study to compare the analgesic efficacy between intravenous remifentanil patient-controlled analgesia (PCA) and levo-bupivacaine with fentanyl PCEA in managing labour pain. Both methods applied background infusion to achieve a baseline level of pain control with the option to self-administer additional doses of analgesics to control pain. We used a simplified remifentanil PCA regimen with the aim to minimize unwanted maternal and neonatal side effects and at the same time, avoid tedious calculations that may give rise to error and thus, cause more harm. A total of 45 participants were recruited and randomly distributed to either the remifentanil group who received 20 µg boluses of remifentanil with 2 minutes lock-out time and 80-120 µg/hour remifentanil background infusion or the PCEA group who received 10 ml boluses of 0.05% levo-bupivacaine andfentanyl 2 µg/ml with 30 minutes lock-out time and 10 ml 0.05% levo-bupivacaine and fentanyl 2 µg/ml background infusion. The verbal reporting scale was used to measure pain score at 15 minutes intervals. Other outcomes assessed included maternal side effects and neonatal well-being. There were no statistical differences in pain scores between both groups during the first 45 minutes. However, from 60 to 120 minutes into the trial, the PCEA group had significantly lower pain scores than the remifentanil group but despite this difference, all participants were satisfied with pain control. Apart from significantly higher sedation scores in the remifentanil group, there were no significant differences in other maternal side effects and neonatal outcome.

In conclusion, intravenous remifentanil PCA is a good alternative to PCEA in managing labour pain and it is safe for both the mother and newborn.