Comparison of Intravenous and Epidural Patient-Controlled Analgesia after Knee and Hip Arthroplasty

Background: Physiological responses to pain and trauma have negative and dangerous effects on all organs. The aim of this study was to compare intravenous and epidural methods of patient-controlled analgesia (PCA) in patients undergoing hip and knee replacement surgeries. Methods: In a double-blind controlled clinical trial, 60 American Society of Anesthesiologists (ASA) I-III subjects were selected from 40-80 year-old patients undergoing hip or knee arthroplasty. They were randomly allocated into two different groups. The first group received intravenous morphine PCA while the second group received a combination of bupivacaine and fentanyl through an epidural catheter. As placebo, normal saline was administered through an epidural catheter in the first group and intravenously in the second group. Data was collected using a questionnaire and then analyzed by student's t-test, repeated measures analysis of variance (ANOVA), and Mann-Whitney and chi-square tests. Findings: Pain intensity after 12 and 24 hours was significantly higher in the epidural group compared to the intravenous group (1.71 ± 1.62 vs. 1.37 ± 0.53). Obviously, the satisfaction rate was significantly higher in the intravenous group. In addition, the side effects in the intravenous group 12 hours after surgery were less prevalent than the epidural group (92.3% vs. 100%). Itching was significantly more common in the epidural group compared to the intravenous group (31% vs. 7.1%; P < 0.05). Blood pressure at the 6th hour after surgery dropped significantly from 132 ± 22 to 111 ± 23 in the epidural group (P < 0.05). Conclusion: In this study, postoperative pain was better controlled by intravenous morphine PCA. However, the level of consciousness was lower in this group. The overall satisfaction rate was higher using this method. On the other hand, in the epidural PCA group, pain was not controlled and patients experienced reductions in blood pressure. Itching was higher in this group of patients. Keywords: Patient-controlled analgesia, Epidural anesthesia, Postoperative pain