Comparison of Fentanyl plus different doses of dexamethasone with Fentanyl alone on postoperative pain, nausea, and vomiting after lower extremity orthopedic surgery.

Intravenous patient controlled analgesia (PCA) with opioids to provide perioperative analgesia is commonly used after orthopedic surgery, but have side-effects. Addition of adjutant drugs results in reducing the side-effects and the dosage of opioids. The aim of current study was to evaluation the analgesic efficacy of combination of fentanyl and dexamethasone (8 and 16 mg) in compared with fentanyl alone in patients undergoing orthopedic surgery of the lower extremity. In a double-blind clinical trial, 102 patients were randomly allocated to receive PCA, which included: F+S group (fentanyl 1 mcg/ml + isotonic saline), F+8mD group (fentanyl 1 mcg/ml + dexamethasone 8 mg/ml), and F+16mD group (fentanyl 1 mcg/ml + dexamethasone 16 mg/ml). Anesthesia technique and rescue analgesia regimen were standardized. Postoperatively, pain was assessed based on visual analog scale (VAS). In addition, we evaluated the postoperative nausea and vomiting (POVN) in different groups. In over the post-operative period, the mean VAS-score was significantly lower in the F+16mD group than the F+S and the F+8mD groups (p<0.001 and p<0.01, respectively). In addition, the incidence of PONV significantly was lower in the F+18mD group than the F+S group (p<0.05). We conclude that the addition of preoperative intravenous high dose of dexamethasone (16 mg) to fentanyl was effective in reducing postoperative pain and PONV after orthopedic surgery of the lower extremity.