Effect of a Single Dose of Dexamethasone on Postoperative Pain and Nausea in Patients Undergoing Spinal Anesthesia: A Randomized Controlled Study

Background: Dexamethasone, a glucocorticoid with minimal mineralocorticoid activity, is often administered perioperatively to reduce postoperative nausea and is an effective analgesic. This study evaluated the impact of a single dose of dexamethasone (2 ml, 10 mg) on postoperative pain and nausea in patients undergoing spinal anaesthesia. Methods: This randomised, double-blind controlled trial included patients undergoing surgery under spinal anaesthesia. Participants were randomly allocated to receive either dexamethasone 10 mg (2 ml) or 0.9% NaCl (placebo) intravenously at the start of the procedure. Postoperative pain was assessed using the Visual Analogue Scale (VAS) at multiple time points (T1 to T4), and the incidence of postoperative nausea and vomiting (PONV) was recorded. Rescue analgesia with ketorolac (30 mg) was administered if the VAS score exceeded 4. Results: The dexamethasone group had the highest frequency of VAS 3 (41.7%) and VAS 2 values (38.9%). The placebo group had the highest frequencies of both VAS 3 and VAS 4 values (41.7% each), and VAS 5 values (41.7%). The VAS values in the control group were higher on average than those in the treatment group. In the control group, there was a slight increase in the average VAS value at T1 (6 h postoperatively), which decreased after analgesic rescue because the VAS value exceeded 4, resulting in a decrease from T2 to T4. Conclusion: A single dose of dexamethasone, 2 ml (10 mg), significantly impacts PONV incidence, with a p-value of 0.007, indicating a statistically significant relationship.