Analgesic clinical trials failing to assess movement-evoked postoperative pain

Editor's Note

Most surgical studies still do not report movement-evoked postoperative pain despite the recommendations of expert consensus groups, according to findings published November 27 in Anesthesiology.

Researchers came to essentially the same conclusion upon re-evaluating the assessment of pain at rest and movement-evoked pain in 2011. In this updated review of more recent postsurgical analgesic clinical trials, they call out a “persistent limited proportion of trials including movement-evoked pain as a pain outcome, a substantial proportion of trials failing to distinguish between pain at rest and movement-evoked pain, and a lack of consistency in the use of pain-evoking maneuvers for movement-evoked pain assessment.”

Using methods consistent with the original 2011 review, authors searched MEDLINE and Embase for postsurgical pain randomized controlled trials and meta-analyses published between 2014 and 2023, focusing on thoracotomy, knee arthroplasty, and hysterectomy. Among the 944 studies included in the review, 504 (53%) did not measure movement-evoked pain (vs. 61% in 2011), and 428 (45%) did not distinguish between pain at rest and movement-evoked pain when defining the pain outcome (vs. 52% in 2011). Among the 439 trials that measured movement-evoked pain, selection of pain-evoking maneuver was highly variable and, notably, was not even described in 139 (32%) trials (vs. 38% in 2011). Among the 186 included meta-analyses, 94 (51%) did not distinguish between pain at rest and movement-evoked pain (vs. 71% in 2011).

Postoperative movement-evoked pain  is generally more intense, the authors note. “Future postsurgical trials need to (1) use common terminology surrounding pain at rest and movement-evoked pain, (2) assess movement-evoked pain in virtually every trial if not contraindicated, and (3) standardize movement-evoked pain assessment with common, procedure-specific pain-evoking maneuvers,” the researchers conclude.