Caudal bupivacaine vs intravenous morphine on time to first analgesic requirement in paediatric surgical patients; a randomised controlled trial

Abstract

BACKGROUND Postoperative pain causes significant suffering and stress. Strides have been made in the last 20 years to control pain in adults however this lagged behind in children due to the misconceptions that children do not experience pain as much as their adult counterparts and the fear of opioid use in children. The objective of this study was to compare the time to next requirement for breakthrough analgesia in pediatric patients receiving either caudal bupivacaine or intravenous morphine and compare the post-operative pain scores for children in both arms. METHODOLOGY Ethical approval was thought to do the study among pediatric surgical patients due for elective abdominal and perineal surgery. The study was a randomized open label trial and American society of anesthesiologists 1 and II patients aged less than 8 were randomized using block randomization to receive either 1ml/kg of 0.125% caudal bupivacaine or 0.05mg/kg intravenous morphine at the end of surgery. The time to the next requirement for breakthrough analgesia was recorded and the hourly mean post operative pain scores for patients in the study calculated. A statistical difference giving a p value of 0.05 was considered significant. RESULTS We enrolled 82 patients and recruited 70 participants for this study with 34 allocated to the morphine arm and 36 allocated to the caudal arm. The time to next requirement for analgesia was 6.7+/- 4.3 hours for caudal and 6.0+/-2 hours for intravenous morphine however this was not statistically significant. The pain scores in both patient populations were comparable with both groups having similar mean post-operative pain scores. CONCLUSION Caudal bupivacaine 0.125% at 1ml/kg had an equal time to first analgesic requirement and similar pain scores to intravenous morphine at 0.05mg/kg in pediatric surgical patients at Mulago hospital.