Comparison between Plain Bupivacaine Alone and Plain Bupivacaine with Dexamethasone Regarding the Duration of Epidural Anesthesia and Postoperative Analgesia in Orthopedic Surgery

Background: Several additives have been trialled to prolong the duration of single injection epidural anesthesia and analgesia, adding glucocorticoids to local anesthetics for regional anesthesia is an emerging strategy. Aim: To evaluate the effect of the addition of dexamethasone to epidural bupivacaine on the duration of epidural anesthesia and postoperative analgesia. Method: A prospective, randomized, double-blind, clinical trial study was conducted in Ghazi Al-Hariri Hospital for Surgical Specialties / Iraq during the period from 1st of October 2021 to 1st of October 2022. A total of 100 patients who underwent orthopedic surgery for hip or knee replacement under epidural anesthesia were included and were allocated into the intervention group (included 50 patients received 15 ml epidural plain bupivacaine (0.5%) plus 8 mg (2 ml) dexamethasone and the control group (included 50 patients who received 15 ml epidural plain bupivacaine (0.5%) plus 2 ml normal saline. Results: There was no significant difference between the study group regarding the onset of the anesthesia (P-value=0.086). There was significantly lower number of patients who need a second dose in the intervention group compared to the control group (P-value=0.001). The duration of anesthesia was significantly longer in the intervention group compared to the control group (P-value=0.001). The mean visual analogue score was significantly lower in the intervention group at 8, 12, 16, 20, and 24 hours. In addition, the mean time to the first analgesic request was significantly longer in the intervention group compared to the control group (P-value =0.001). Conclusion: The addition of dexamethasone to epidural bupivacaine increased the duration of epidural anesthesia and decreased postoperative pain and the need for analgesic drugs compared to epidural bupivacaine alone.