Analgesic efficacy of pre‐operative stellate ganglion block on postoperative pain relief: a randomised controlled trial

We undertook a randomised, double-blind, placebo-controlled study to compare the analgesic efficacy of pre-operative stellate ganglion block on postoperative pain relief after upper limb orthopaedic surgery. Patients were administered a 3-ml injection during ultrasound-guided stellate ganglion block; 15 patients received lidocaine 2% and 15 patients received 0.9% saline. Following the block, all patients received standardised general anaesthesia. Postoperative analgesia included regular intravenous diclofenac, paracetamol and patient-controlled analgesia with tramadol for 24 h. Patients were observed at 0, 2, 4, 6, 8, 12 and 24 h after surgery for tramadol consumption, cardiovascular variables and visual analogue scale pain scores at rest and on movement. The mean (SD) hourly tramadol consumption was significantly reduced in the lidocaine group compared with the saline group at 4 h (8.0 (10.1) mg vs 28.0 (12.6) mg, respectively; p = 0.001), 6 h (5.3 (10.8) mg vs 17.3 (12.7) mg, respectively; p = 0.013) and 8 h (5.3 (11.8) mg vs 21.3 (9.1) mg, respectively; p = 0.001). The cumulative 24-h tramadol consumption was 97.3 (16.6) mg in the lidocaine group and 150.6 (26.0) mg in the saline group (p = 0.001). There were significant differences in the pain visual analogue scale at rest at two time points; at 4 h the median (IQR [range]) visual analogue scale scores were 4 (4-6 [2-8]) in the lidocaine group and 5 (4-6 [2-7]) in the saline group (p = 0.03), and at 6 h visual analogue scale scores were 3 (3-4 [3-6]) and 4 (4-6 [2-7]), respectively (p = 0.04). Pain visual analogue scale on movement was lower in the lidocaine group at all time intervals compared with the saline group, but this did not reach statistical significance. The present study has demonstrated a postoperative tramadol-sparing and analgesic effect of pre-operative stellate ganglion block in patients undergoing upper limb orthopaedic surgery under general anaesthesia.