Document resource
Brachial plexus blocks provide excellent analgesia during the sensory blockade. However, the abrupt termination of the analgesic effect after single-injection techniques, often referred to as «rebound pain», is a major problem that needs consideration. Without sufficient prophylaxis, up to 50–80% of patients report strong pain (NRS 7–10) at block resolution. 1–4 This pain is especially problematic in ambulatory surgery, where the patients are often discharged and at home when the nerve block wears off. Sufficient prophylactic strategies may reduce the incidence significantly.5 6 The major strategies suggested to reduce strong pain at block resolution are to identify patients at risk, thoroughly inform all patients, use timely multimodal and prophylactic analgesia, add adjuvant medication to prolong block duration, and use continuous brachial plexus blocks when adequate. It is important to combine several strategies. Vulnerable patients should be identified. The presence of preoperative pain, younger age, female gender, surgery involving bone, and psychosocial factors like depression or a catastrophic perception of pain are known risk factors for strong pain at block resolution.1 2 7 8 All patients receiving brachial plexus blocks should be informed thoroughly and repeatedly regarding the expected post-surgical pain, block duration and offset, and how to manage the pain when the nerve block resolves. Whereas patients emerging from general anaesthesia usually receive titrated analgesics in the PACU, patients with a brachial plexus block usually leave the PACU pain-free. At block resolution, often in the middle of the night, the patients are usually in the ward or discharged at home without professional guidance for titration of analgesia.9 10 A perioperative plan for pain management is therefore crucial to prevent strong pain and help patients better handle the situation. The use of multimodal and prophylactic analgesia is important. The patients should be informed about both medical and non-medical measures to reduce pain. The analgetic regime should be initiated timely and include paracetamol, anti-inflammatory prophylaxis with NSAIDs or COX-2 inhibitors, and oral rescue opioids in patients without contraindications. Other analgesics should be considered according to the expected postoperative pain. If the patients experience pain at block resolution, they should be instructed to take analgesics earlier rather than later to reduce the intensity and severity of the pain. As nociceptive input and pain usually decline during the hours after surgery, measures to prolong the duration of the sensory block seem to reduce pain at brachial plexus block resolution.5 11–13 Current measures may include long-acting local anaesthetic solutions, the use of oral, intravenous, or perineural adjuvants, or continuous nerve block catheters. Local anaesthetic solution should be chosen according to the expected pain after surgery. To further increase the duration of the nerve block, oral, intravenous, or perineural adjuvants could be added. Adjuvants suggested for brachial plexus blocks include adrenaline, clonidine, dexmedetomidine, ketamine, magnesium, dexamethasone and buprenorphine. Most of them are not officially approved for perineural administration.14 Dexamethasone is so far the single most important and best documented strategy to reduce strong pain at nerve block resolution. Studies exploring the effect of dexamethasone have found only minor differences between perineural and intravenous administration. An interesting study on bilateral saphenous nerve blocks found only an inconsistent and modest block prolongation on the side with perineural dexamethasone of minor clinical importance; hence, the effect of dexamethasone seems to be mainly systemic.15 A systematic review and meta-analysis comparing perineural with intravenous dexamethasone found prolonged analgesia with the perineural approach when injected with bupivacaine (approximately 4 hours), but not with ropivacaine.16 Both iv and perineural doses of more than 8 mg of dexamethasone seem to result in similar prolongation of ropivacaine blocks.16–19 Oral dexamethasone is also shown to prolong nerve block duration and significantly reduce rebound pain.20 As the effect of perineural and intravenous dexamethasone seems to be similar, and dexamethasone is not licensed for perineural use, intravenous or oral use is recommended. Perineural clonidine and dexmedetomidine prolong nerve block duration but are not shown to reduce pain at block resolution.6 The use is associated with side effects like sedation, bradycardia, and dizziness.6 Compared with dexamethasone for brachial plexus blocks, dexmedetomidine seems to be an inferior adjunct as it has a shorter duration of analgesia (equivalent to 2.5 hours) with more prominent side-effects.21 Therefore, dexamethasone seems to be a better alternative for most patients. Ketamine has shown conflicting results, and it is currently unclear if it reduces the occurrence of rebound pain at block resolution,4 6 18 22 whereas intravenous magnesium has recently been suggested to prolong nerve block duration and reduce rebound pain.23 Both intravenous and perineural buprenorphine prolong the duration of postoperative analgesia, but lead to a significant increase in PONV and carry a risk of sedation and respiratory depression, which makes dexamethasone a better alternative for most patients.24 The use of liposomal bupivacaine to prolong the duration of nerve blocks has been highly debated, and several meta-analyses have failed to show clinically relevant differences compared with conventional long-acting local anaesthetic solutions.25 26 A recently published review article by Hardrick and colleagues on liposomal bupivacaine for brachial plexus blocks shows moderately decreased pain scores on postoperative day 1 and 2 and a small reduction in postoperative opioid consumption (-3.51 OMED) compared with bupivacaine or ropivacaine. However, they concluded the differences may not be of clinical significance and that the benefits for the patients were questionable and may not justify the increased costs.27 A well-placed nerve block catheter provides excellent analgesia for several days after surgery.7 The drawback is that the procedure is time-consuming and more challenging than a single injection technique, is more labour-intensive to manage, and the catheters have an inherent failure rate and may dislocate. Therefore, the technique is usually reserved for patients with expected strong postoperative pain for several days. To summarise, to reduce strong pain at brachial plexus block resolution, oral or intravenous dexamethasone prolong nerve block duration, reduce inflammation and subsequently pain, and seem to be the single most important strategy to reduce pain at block resolution. Dexamethasone should be combined with thorough patient education and preventive and multimodal analgesic strategies.References Barry GS, Bailey JG, Sardinha J, Brousseau P, Uppal V. Factors associated with rebound pain after peripheral nerve block for ambulatory surgery. Br J Anaesth. 2021;126(4):862–71.Lavand’homme P. Rebound pain after regional anesthesia in the ambulatory patient. Curr Opin Anaesthesiol. 2018;31(6):679–84.Holmberg A, Sauter AR, Klaastad O, Draegni T, Raeder JC. Pre-operative brachial plexus block compared with an identical block performed at the end of surgery: a prospective, double-blind, randomised clinical trial. Anaesthesia 2017;72(8):967–77.Jeng CL. (April 15, 2025). Overview of peripheral nerve blocks. In: UpToDate, Maniker R (Ed), Wolters Kluwer. (Accessed: June 20, 2025).Holmberg A, Hassellund SS, Draegni T, Nordby A, Ottesen FS, Gulestol A, et al. Analgesic effect of intravenous dexamethasone after volar plate surgery for distal radius fracture with brachial plexus block anaesthesia: a prospective, double-blind randomised clinical trial(). Anaesthesia 2020;75(11):1448–60.Murphy KJ, O’Donnell B. Rebound pain-management strategies for transitional analgesia: a narrative review. J Clin Med. 2025;14(3).Munoz-Leyva F, Cubillos J, Chin KJ. Managing rebound pain after regional anesthesia. Korean J Anesthesiol. 2020;73(5):372–83.Sort R, Brorson S, Gogenur I, Nielsen JK, Moller AM. Rebound pain following peripheral nerve block anaesthesia in acute ankle fracture surgery: an exploratory pilot study. Acta Anaesthesiol Scand. 2019;63(3):396–402.Sunderland S, Yarnold CH, Head SJ, Osborn JA, Purssell A, Peel JK, et al. Regional versus general anesthesia and the incidence of unplanned health care resource utilization for postoperative pain after wrist fracture surgery: results from a retrospective quality improvement project. Reg Anesth Pain Med. 2016;41(1):22–7.Galos DK, Taormina DP, Crespo A, Ding DY, Sapienza A, Jain S, et al. Does brachial plexus blockade result in improved pain scores after distal radius fracture fixation? A randomized trial. Clin Orthop Relat Res. 2016;474(5):1247–54.Barrio J, Madrid E, Gil E, Richart MT, Sanchez de Meras A. Influence of sensory block duration on rebound pain after outpatient orthopaedic foot surgery under popliteal sciatic nerve block: an observational study. Anaesthesia 2025;80(5):582–3.Williams BA, Bottegal MT, Kentor ML, Irrgang JJ, Williams JP. Rebound pain scores as a function of femoral nerve block duration after anterior cruciate ligament reconstruction: retrospective analysis of a prospective, randomized clinical trial. Reg Anesth Pain Med. 2007;32(3):186–92.Luebbert E, Rosenblatt MA. Postoperative rebound pain: our current understanding about the role of regional anesthesia and multimodal approaches in prevention and treatment. Curr Pain Headache Rep. 2023;27(9):449–54.Albrecht E, Chin KJ. Advances in regional anaesthesia and acute pain management: a narrative review. Anaesthesia 2020;75 Suppl 1:e101-e10.Jæger P, Grevstad U, Koscielniak-Nielsen ZJ, Sauter AR, Sørensen JK, Dahl JB. Does dexamethasone have a perineural mechanism of action? A paired, blinded, randomized controlled study in healthy volunteers. Br J Anaesth. 2016;117(5):635–41)Baeriswyl M, Kirkham KR, Jacot-Guillarmod A, Albrecht E. Efficacy of perineural vs systemic dexamethasone to prolong analgesia after peripheral nerve block: a systematic review and meta-analysis. Br J Anaesth. 2017;119(2):183–91.Desmet M, Braems H, Reynvoet M, Plasschaert S, Van Cauwelaert J, Pottel H, et al. I.V. and perineural dexamethasone are equivalent in increasing the analgesic duration of a single-shot interscalene block with ropivacaine for shoulder surgery: a prospective, randomized, placebo-controlled study. Br J Anaesth. 2013;111(3):445–52.Touil N, Pavlopoulou A, Barbier O, Libouton X, Lavand’homme P. Evaluation of intraoperative ketamine on the prevention of severe rebound pain upon cessation of peripheral nerve block: a prospective randomised, double-blind, placebo-controlled study. Br J Anaesth. 2022;128(4):734–41.Rosenfeld DM, Ivancic MG, Hattrup SJ, Renfree KJ, Watkins AR, Hentz JG, et al. Perineural versus intravenous dexamethasone as adjuncts to local anaesthetic brachial plexus block for shoulder surgery. Anaesthesia 2016;71(4):380–8.Maagaard M, Plambech MZ, Funder KS, Schou NK, Molgaard AK, Stormholt ER, et al. The effect of oral dexamethasone on duration of analgesia after upper limb surgery under infraclavicular brachial plexus block: a randomised controlled trial. Anaesthesia 2023;78(12):1465–71.Albrecht E, Vorobeichik L, Jacot-Guillarmod A, Fournier N, Abdallah FW. Dexamethasone is superior to dexmedetomidine as a perineural adjunct for supraclavicular brachial plexus block: systematic review and indirect meta-analysis. Anesth Analg. 2019;128(3):543–554.Li Q, Tian S, Zhang L, Chai D, Liu J, Sheng F, et al. S-Ketamine reduces the risk of rebound pain in patients following total knee arthroplasty: a randomized controlled trial. Drug Des Devel Ther. 2025;19:2315–27.Soeding P, Morris A, Soeding A, Hoy G. Effect of intravenous magnesium on post-operative pain following Latarjet shoulder reconstruction. Shoulder Elbow 2024;16(1):46–52.Schnabel A, Reichl SU, Zahn PK, Pogatzki-Zahn EM, Meyer- Frie.em CH. Efficacy and safety of buprenorphine in peripheral nerve blocks: a meta-analysis of randomised controlled trials. Eur J Anaesthesiol. 2017;34:576–586.Poeran J, Hong G, Memtsoudis SG. Free academic discourse and the law: the case of liposomal bupivacaine. Reg Anesth Pain Med. 2023;48(10):526–529.Lahaye L, Coleman JR (February 4, 2025). Clinical use of local anesthetics in anesthesia. In: UpToDate, Maniker R (Ed), Wolters Kluwer. (Accessed: June 29, 2025).Hardrick J, et al. Orthopaedics and traumatology: surgery & research. https://doi.org/10.1016/j.otsr.2025.104190