Evaluation of Three Concentrations of Epidural Bupivacaine for Postoperative Pain Relief: A Prospective Observational Study

Abstract

Background: Postoperative dynamic pain is often associated with increased morbidity and hospital stays. Thoracic epidural analgesia is the gold standard for postoperative pain control in patients with upper abdominal surgeries, providing significant improvements in dynamic pain scores and early mobilisation. The primary objective of this study is to evaluate postoperative static and dynamic pain control with three concentrations of thoracic epidural bupivacaine mixed with a fixed dose of fentanyl infusion in major abdominal surgeries. Method: The patients meeting the inclusion criteria were randomly allocated to three different groups. Thoracic epidural bupivacaine infusions, with concentrations of 0.0625%, 0.1% and 0.125%, mixed with fentanyl 1 μg/mL, were given through a Baxter elastomeric pump at the rate of 5 mL/hour, and labelled as Group A, Group B and Group C, respectively. The patients were followed up to the third postoperative day for the assessment of static pain score, dynamic pain score, respiratory depression, blood pressure, sedation, motor weakness, postoperative nausea and vomiting. Results: Group B and Group C, with bupivacaine concentrations of 0.1% and 0.125%, respectively, had significantly better static and dynamic pain control in comparison to Group A, with a bupivacaine concentration of 0.0625%. Hypotension was significantly higher in Group C than in other groups. The incidence of other side effects, including motor block, pruritus, postoperative nausea and vomiting, were found to be highest in Group C compared to the other groups, though the difference was not significant. Conclusion: We recommend a thoracic epidural infusion with a bupivacaine concentration of 0.1% with 1 µg/mL fentanyl for postoperative pain management in patients undergoing major abdominal surgery.