The addition of fentanyl to 1.5 mg/ml ropivacaine has no advantage for paediatric epidural analgesia

Abstract

Background: Epidural opioids are frequently combined with local anaesthetics for an additive antinociceptive effect. We investigated the efficacy of epidural fentanyl to 1.25 or 1.5 mg/ml ropivacaine for post-operative epidural analgesia in children.

Methods: One hundred and eight children undergoing hypospadias repair were randomized to receive 1.25 mg/ml ropivacaine (R1.25 group), 1.25 mg/ml ropivacaine with 0.2 mcg/kg/h of fentanyl (R1.25F group), 1.5 mg/ml ropivacaine (R1.5 group) or 1.5 mg/ml ropivacaine with 0.2 mcg/kg/h of fentanyl (R1.5F group) for post-operative epidural analgesia. The epidural catheter was threaded caudally through the L4-5 interspace. The face, legs, activity, cry, consolability (FLACC) score was assessed at every hour and at FLACC score >4, an epidural bolus of 0.5 ml/kg of ropivacaine 1.5 mg/ml was given as the rescue analgesia. The incidence of side effects such as hypoxia, sedation, pruritus, nausea and/or vomiting was recorded.

Results: The need for rescue analgesia was higher in the R1.25 group compared with that in the other three groups (all P<0.05). The incidence of side effects was higher in the R1.5F group compared with that in the R1.25 and R1.5 groups (both P=0.010).

Conclusion: The addition of 0.2 mcg/kg/h fentanyl to 1.5 mg/ml ropivacaine increased the incidence of side effects without improvement of analgesia in infants and children undergoing hypospadias repair. The use of plain 1.25 mg/ml ropivacaine increased the need for rescue analgesia and this could be compensated by addition of fentanyl.