The Effect of Single-dose Intravenous Dexamethasone on Postoperative Pain and Postoperative Nausea and Vomiting in Patients Undergoing Surgery under Spinal Anesthesia: A Double-blind Randomized Clinical Study

BACKGROUND: The use of neuraxial anesthesia has dramatically increased. Acute postoperative pain is an undesirable outcome that can delay functional recovery for patients undergoing surgery. Nausea and vomiting in the postoperative period occurs in 20%–30% of the patients and together are the second-most common complaint reported (pain is the most common). Efficacy of glucocorticoids for reducing pain and inflammation after surgery is being explored. Glucocorticoids are strong anti-inflammatory agents, which can be used for a short-time postoperative pain control in various surgeries. Dexamethasone is a glucocorticoid with little mineralocorticoid effect commonly used perioperatively to reduce postoperative nausea and vomiting (PONV) and has a beneficial role in postoperative analgesia. Dexamethasone has also an antiemetic effect, in addition to its anti-inflammatory and analgesic effects. AIM: The main purpose of this study is to evaluate the effect of administration of single-dose intravenous (i.v.) dexamethasone on postoperative pain and PONV in patients undergoing surgery under spinal anesthesia. SETTINGS AND DESIGN: A double-blind randomized clinical study was performed in our institute between November 2014 and October 2015 after obtaining clearance from the ethical committee. MATERIALS AND METHODS: A double-blind randomized clinical study was performed on 60 patients posted for surgery under spinal anesthesia. Patients were randomly assigned into two groups: A (study: 2 ml [8 mg] dexamethasone) and B (control: 2 ml saline). In both the groups, variables such as mean arterial blood pressure (MAP), heart rate (HR), respiratory rate, severity of pain (based on visual analog scale), and other symptoms such as nausea and vomiting were recorded at different time points during the first 24 h after surgery. Statistical methods using Student t-test (two-tailed, independent) and Fischer's exact test were used for analyzing the data. RESULTS: Between-group comparisons indicated significant differences in terms of severity of postoperative pain and PONV (P < 0.001), MAP (P = 0.063), and HR (P = 0.071), which in the study group were lower than the control group. CONCLUSION: i.v. dexamethasone is efficient in reducing postoperative pain, requirement of rescue analgesia on the first postoperative day, and incidence of PONV with no significant changes in vital signs.