Acute pain: Overview

Abstract
Following announcements from professional and governmental bodies across a number of countries, modified-release (MR) opioids are no longer recommended in the routine management of acute pain, and so should not be initiated for this reason. The recommendations are not new, but a recent cluster of publications by key professional and governmental bodies has more clearly challenged their use and highlighted the need for change in guideline-driven and individual practice. The inclusion of MR opioids in many postoperative pain regimens relatively soon after they were first marketed for use in patients with chronic non-cancer pain, was not based on sound evidence, and there remains no evidence of benefit. In contrast, however, good evidence has accumulated that shows they not only provide less effective pain relief compared with immediate-release opioids, but that they lead to a higher risk of adverse effects including opioid-induced ventilatory impairment and persistent opioid use.

Abstract
Objective: To conduct a scoping literature review of patient-reported duration and amount of post-discharge or outpatient opioid analgesic use for acute pain.

Design: We searched PubMed for studies, published from January 1, 2017, through June 27, 2022, describing patient-reported opioid analgesic use after discharge from surgical procedures or other types of acute pain.

Outcomes: We abstracted and standardized information on the duration (days) and amount of use (converted to 5 mg oxycodone tablets using morphine milligram equivalents).

Results: From 86 studies, we found that duration and amount of opioid analgesic use varied greatly across and within surgical procedures. For some minimally invasive procedures, a minority of patients reported using no opioids. Various factors were associated with the duration or amount of opioid analgesic use, such as preoperative opioid use. Gaps and limitations in the literature include: few studies assessing non-surgical acute pain and certain specific surgical procedures, and methodologic differences limiting comparability across studies.

Conclusions: Patient-reported data of opioid analgesic use to manage various types of acute pain helps inform opioid prescribing guidelines, but gaps across the existing literature must be carefully considered. We conclude that (1) there is wide variation in patient-reported opioid analgesic use across types of surgical procedures as well as within surgical procedures, potentially driven by patient, surgical, and institutional factors and (2) there continue to be unused tablets prescribed for many types of postsurgical pain, especially for minimally invasive procedures. In part, this work informed the April 2023 Food and Drug Administration's opioid analgesic labeling changes.

Abstract
Pain is one of the primary indicators of a bone fracture and serves both a functional and practical role in guiding recovery. However, fracture pain can persist long after the fracture itself has clinically healed. The neural and molecular mechanisms that drive acute pain postfracture, and how these mechanisms are pathologically usurped to trap patients into persistent, debilitating, and often difficult to treat, chronic pain, are not well understood. The aim of this review is to provide insight into the risk factors for pain persistence after fracture, review the physiological and pathophysiological mechanisms of fracture pain, and critically evaluate the literature around fracture pain assessment techniques/models. Taken together, the concepts covered herein will provide a strong foundation to support the development of more effective treatments to better alleviate postfracture pain.