A Randomized Double Blinded Trial Comparing Dexmedetomidine With Dexamethasone as an Adjunct to Ropivacaine in Ultrasound Guided Interscalene Block for Arthroscopic Shoulder Surgery.

Abstract

To evaluate the analgesic effi cacy of dexamethasone (DXA) vs. dexmedetomidine (DXM) as an adjunct to ropivacaine in ultrasound-guided interscalene block (USG-ISB) for arthroscopic shoulder surgery. In this randomized double-blinded controlled trial, 60 American Society of Anesthesiologists grade 1-2 patients, 18-65 years, scheduled for arthroscopic shoulder surgery were randomly allocated to either group 1 (USG-ISB given with 0.5% ropivacaine 20 mL with 2 mL of saline containing DXM 0.5 mcg/kg) or group 2 (same protocol but DXA 8 mg instead of DXM). ISB was performed with in-plane technique under USG. Following surgery under general anesthesia, the patients received intravenous patient-controlled analgesia with fentanyl. Data were collected at 2-hourly intervals up to 24 hours after USG-ISB. The primary outcome was the duration of analgesia. Secondary outcomes consisted of pain ratings, total cumulative postoperative fentanyl consumption, patient satisfaction, and adverse effects. The groups were comparable regarding baseline demographic and clinical characteristics including onset of sensory and motor block. The duration of postoperative analgesia for group 2 was signifi cantly longer than for group 1 (22.40 ± 2.16 h vs. 19.30 ± 3.80 h; p < 0.001). Group 2 also required less total median number of boluses than group 1 (0 vs. 3; p < 0.001), less total fentanyl consumption (10.00 mcg ± 24.20 vs. 40.33 mcg ± 38.70; p < 0.001), less pain scores, and greater satisfaction (99.30 ± 2.53 vs. 93.30 ± 11.50; p=0.007). Adverse effects were few and comparable in both groups. Greater postoperative analgesia and opioid sparing effect was observed in patients receiving 8 mg DXA as adjunct for USG-ISB.