Nerve blocks \u2013 local anesthetic injections that block pain signals \u2013 are a valuable opioid-sparing technique for controlling pain after surgery. However, some patients experience temporary sharp increases in pain as the nerve block wears off. This\u00a0phenomenon, often termed\u00a0“rebound pain,” does not result from nerve hypersensitivity\u00a0to painful testing (e.g. heat, pressure, punctate pain), reports a\u00a0healthy volunteer\u00a0study in the\u00a0August issue\u00a0of\u00a0Anesthesiology, the peer-reviewed medical journal of the American Society of Anesthesiologists (ASA).\u00a0<\/p>\n
More likely, the perceived increase in pain is caused by the “unmasking” of surgical pain as the nerve block wears off, suggests author Yun-Yun K. Chen, M.D., of Brigham and Women’s Hospital, Boston. “Concerns about rebound pain should not deter clinicians from using nerve blocks for postoperative pain control. Our findings show no evidence of heightened sensitization – a key driver of\u00a0acute and\u00a0chronic pain<\/a> –\u00a0suggesting that rebound pain is more likely the natural return of surgical discomfort as the block wears off, rather than an alteration in the nerve after local anesthetic blockade.”\u00a0<\/p>\n Nerve blocks are a form of regional anesthesia with many benefits in controlling postoperative pain, including reducing the need for opioids. However, up to half of patients experience\u00a0severe\u00a0worsening pain after the nerve block wears off, sometimes resulting in emergency department visits or readmission. It\u00a0has been\u00a0unclear whether this reflects the return of untreated surgical pain or whether it may result from a hypersensitivity effect caused by the nerve block.\u00a0<\/p>\n To gain insight into\u00a0the mechanism of\u00a0rebound pain, Dr. Chen and colleagues performed an experimental study in 40 healthy volunteers. In one randomly selected arm, all participants received a single-injection axillary brachial plexus block: a type of nerve block routinely used for surgery on the hand and arm. The other arm received no nerve block.\u00a0<\/p>\n For several hours\u00a0during and\u00a0after the nerve block began to wear off, participants underwent tests to evaluate responses to various painful\u00a0stimuli\u00a0using quantitative sensory testing of pain: pinprick, pressure, and heat. The researchers assessed the development of\u00a0hypersensitivity\u00a0by comparing pain responses between the\u00a0block and control\u00a0arms.\u00a0<\/p>\n At no point during the process of block resolution (from time of motor function\u00a0return\u00a0out to 3 hours after) was there\u00a0evidence of rebound pain in the arms undergoing nerve blocks. The heat stimulus needed to produce even mild pain \u2013 one point on a\u00a00-10-point scale \u2013 showed little or no difference between arms. Responses to the other pain stimuli were similar:\u00a0no increase in sensitivity from baseline was detected in the previously blocked arm.\u00a0<\/p>\n Overall, the results showed “no evidence of significant sensitization” in any of the pain tests \u2013 including measures of central sensitization (pain processing by the central nervous system<\/a>). This is an important consideration because central sensitization is thought to be a key step in the development of chronic pain. “These findings suggest that the phenomenon of rebound pain is more likely driven by the surgical pain that emerges once the block\u00a0is\u00a0resolving,” the researchers wrote.\u00a0<\/p>\n The researchers note some limitations of their study \u2013 especially that the participants did not undergo surgery and thus did not experience the expected pain and healing responses after a surgical incision.\u00a0<\/p>\n Our study provides reassurance that nerve blocks are safe and effective for pain control after surgery.”<\/p>\n Dr. Yun-Yun K. Chen, M.D., Brigham and Women’s Hospital, Boston<\/p>\n The researchers discuss strategies to prevent or lessen the impact of rebound pain, highlighting the role of multimodal anesthesia targeting different pain pathways, patient education around “reasonable expectations” for postoperative pain control, and emphasis on anticipating nerve block resolution and appropriately timing pain medication as it approaches.\u00a0<\/p>\n In an accompanying editorial, Benedict Alter, M.D., Ph.D., of the University of Pittsburgh, drew attention to the critical distinction between nociception \u2013 nerve transmission of pain impulses \u2013 and the complex and individual experience of pain. Dr. Alter highlights the “critical and ongoing” efforts to reduce rebound pain after surgery. He concluded: “A better understanding of uncontrolled pain after resolution of nerve blockade will improve postoperative pain management and overall surgical outcomes.”\u00a0<\/p>\n Source:<\/p>\n American Society of Anesthesiologists<\/a><\/p>\n Journal reference:<\/p>\n Chen, Y-Y, K., et al. (2026) Evaluation of Post-block Hypersensitivity Using Quantitative Sensory Testing Before, During, and After Axillary Brachial Plexus Block Resolution in Healthy Volunteers. Anesthesiology. DOI: 10.1097\/ALN.0000000000006082.\u00a0https:\/\/journals.lww.com\/anesthesiology\/abstract\/10.1097\/aln.0000000000006082~evaluation-of-postblock-hypersensitivity-using-quantitative<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Nerve blocks \u2013 local anesthetic injections that block pain signals \u2013 are a valuable opioid-sparing technique for controlling…\n","protected":false},"author":2,"featured_media":14493,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[40095,246451,5296,7422,243,163,2407,4144,185675,85,46,14539,246452,504,514,13583],"class_list":["post-541301","post","type-post","status-publish","format-standard","has-post-thumbnail","category-health","tag-anesthesiology","tag-brachial-plexus","tag-chronic","tag-chronic-pain","tag-education","tag-health","tag-heat","tag-hospital","tag-hypersensitivity","tag-il","tag-israel","tag-nerve","tag-nerve-block","tag-pain","tag-pain-management","tag-surgery"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/541301","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=541301"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/541301\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/14493"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=541301"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=541301"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=541301"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}