The analgesic efficacy of forearm vfversus upper arm intravenous regional anesthesia (Bier's block): A randomized controlled non-inferiority trial.

Abstract Study objective This study aimed to assess if a forearm (FA) intravenous regional anesthesia (IVRA) with a lower, less toxic, local anesthetic dosage is non-inferior to an upper arm (UA) IVRA in providing a surgical block in patients undergoing hand and wrist surgery. Design Observer-blinded, randomized non-inferiority study. Setting Operating room. Patients 280 patients undergoing hand surgery were randomly assigned to UA IVRA (n = 140) or FA IVRA (n = 140). Interventions Forearm IVRA or upper arm IVRA in patients undergoing hand and wrist surgery. Measurements The primary outcome was block success rate of both techniques. Block success was defined as no need of additional analgesics. A second, alternative non-inferiority outcome was defined as no need of conversion to general anesthesia. A difference in success rate of Main results Non-inferiority of block success rate, defined as no need of additional analgesics or conversion to general anesthesia was inconclusive (5.24%, 95% CI:-4.34%,+14.82%). Non-inferiority of no need of conversion to general anesthesia was confirmed (+0.73%, 95% CI:-0.69%,+2.15%). No differences were observed in onset time (FA: 5 (5, 8) vs UA: 6 (5, 7) min, p = 0.74), surgical time (FA: 8 (5, 12) vs UA: 7 (5, 11) min, p = 0.71), nor total OR stay time (FA: 34 (27, 41) vs UA: 35 (32, 39) min, p = 0.09). Tourniquet pain after 10 min was significantly lower after FA IVRA compared to UA IVRA (FA: 2.00 (0.00, 4.00) vs UA: 3.00 (1.00,5.00) min, p = 0.003). Conclusion We failed to demonstrate non-inferiority of forearm IVRA with a lower dosage of LA in providing a surgical block without rescue opioids and LA. Non-inferiority of no need of conversion to general anesthesia was confirmed.