Effect of a single bolus of dexamethasone on intraoperative and postoperative pain in unilateral inguinal hernia surgery

Background and Aims: Opioids are commonly used to provide perioperative analgesia, but have many side-effects. Addition of co-analgesics results in reducing the dosage and hence the side-effects of opioids. The objective of this study was to compare the analgesic efficacy of fentanyl (1 micro/kg^-1) administered alone, with fentanyl (0.75 micro/kg^-1) and dexamethasone (8 mg) combination, in patients undergoing day care unilateral inguinal hernia repair. Material and Methods: Patients scheduled for the day care unilateral inguinal hernia repair were randomized to receive either saline and fentanyl 1 micro/kg^-1 (control group) or 8 mg dexamethasone with fentanyl 0.75 micro/kg^-1 (study group) immediately before induction of anesthesia in a double-blind clinical trial. Anesthesia technique and rescue analgesia regimen were standardized. Intraoperatively, pain was assessed based on hemodynamic variability and postoperatively by visual analog scale. Results: The mean heart rate, systolic and the diastolic blood pressure at 1, 5, 20 and at 30 min after incision, were significantly higher in the control group (P ≤ 0.001) when compared to the study group. Intra-operative rescue analgesia was required in 32 (100%) and 19 (59.4%) patients in control group and study group respectively (P = 0.0002). Mean pain scores measured at fixed time periods postoperatively were significantly higher in the control group when compared to study group (P ≤ 0.001). Postoperative rescue analgesia was needed in 32 (100%) versus 24 (75%) patients in the control group and study group respectively, but this difference was not statistically significant (P = 0.285). Conclusion: We conclude that the addition of 8 mg of preoperative intravenous dexamethasone to 0.75 micro/kg^-1 fentanyl was effective in reducing intraoperative and postoperative pain in the 1 ^st h after unilateral inguinal hernia surgery.