Movement-evoked Pain versus Pain at Rest in Postsurgical Clinical Trials and in Meta-analyses: An Updated Systematic Review.

Background: Given the widespread recognition that postsurgical movement-evoked pain is generally more intense, and more functionally relevant, than pain at rest, the authors conducted an update to a previous 2011 review to re-evaluate the assessment of pain at rest and movement-evoked pain in more recent postsurgical analgesic clinical trials.

Methods: The authors searched MEDLINE and Embase for postsurgical pain randomized controlled trials and meta-analyses published between 2014 and 2023 in the setting of thoracotomy, knee arthroplasty, and hysterectomy using methods consistent with the original 2011 review. Included trials and meta-analyses were characterized according to whether they acknowledged the distinction between pain at rest and movement-evoked pain and whether they included pain at rest and/or movement-evoked pain as a pain outcome.

AAAPT Diagnostic Criteria for Acute Thoracic Surgery Pain.

Patients undergoing thoracic surgery experience particular challenges for acute pain management. Availability of standardized diagnostic criteria for identification of acute pain after thoracotomy and video assisted thoracic surgery (VATS) would provide a foundation for evidence-based management and facilitate future research. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the United States Food and Drug Administration, the American Pain Society (APS), and the American Academy of Pain Medicine (AAPM) formed the ACTTION-APS-AAPM Pain Taxonomy (AAAPT) initiative to address absence of acute pain diagnostic criteria.

Deep Tissue Incision Enhances Spinal Dorsal Horn Neuron Activity During Static Isometric Muscle Contraction in Rats.

Translational correlates to pain with activities after deep tissue injury have been rarely studied. We hypothesized that deep tissue incision causes greater activation of nociception-transmitting neurons evoked by muscle contraction. In vivo neuronal activity was recorded in 203 dorsal horn neurons (DHNs) from 97 rats after sham, skin-only, or skin + deep muscle incision.

Effect of Thoracic Epidural Anesthesia in a Rat Model of Phrenic Motor Inhibition after Upper Abdominal Surgery.

What We Already Know About This Topic: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: One important example of impaired motor function after surgery is diaphragmatic dysfunction after upper abdominal surgery. In this study, the authors directly recorded efferent phrenic nerve activity and determined the effect of the upper abdominal incision. The authors hypothesized that phrenic motor output would be decreased after the upper abdominal incision; it was also hypothesized that blocking sensory input from the incision using thoracic epidural anesthesia would diminish this incision-induced change in phrenic motor activity.

Ovine model of neuropathic pain for assessing mechanisms of spinal cord stimulation therapy via dorsal horn recordings, von Frey filaments, and gait analysis.

Background: It is becoming increasingly important to understand the mechanisms of spinal cord stimulation (SCS) in alleviating neuropathic pain as novel stimulation paradigms arise.

Purpose: Additionally, the small anatomic scale of current SCS animal models is a barrier to more translational research.

Methods: Using chronic constriction injury (CCI) of the common peroneal nerve (CPN) in sheep (ovine), we have created a chronic model of neuropathic pain that avoids motor deficits present in prior large animal models.

Preoperative Patient Expectations of Postoperative Pain Are Associated with Moderate to Severe Acute Pain After VATS.

Objective: The goal of this post hoc analysis of subjects from a prospective observational study was to identify the predictors of patients developing moderate to severe acute pain (mean numerical rating scale [NRS] ≥4, 0-10) during the first three days after video-assisted thoracoscopic surgery (VATS) from a comprehensive evaluation of demographic, psychosocial, and surgical factors.

Methods: Results from 82 patients who were enrolled one week before VATS and evaluated during the first three postoperative days are presented. The primary outcome variable of the current study was the presence of moderate to severe acute pain after VATS.

Hydrogen Peroxide Induces Muscle Nociception via Transient Receptor Potential Ankyrin 1 Receptors.

Background: H2O2 has a variety of actions in skin wounds but has been rarely studied in deep muscle tissue. Based on response to the transient receptor potential ankyrin 1 antagonists after plantar incision, we hypothesized that H2O2 exerts nociceptive effects via the transient receptor potential ankyrin 1 in muscle.

Methods: Nociceptive behaviors in rats (n = 269) and mice (n = 16) were evaluated after various concentrations and volumes of H2O2 were injected into the gastrocnemius muscle or subcutaneous tissue.

The ACTTION-APS-AAPM Pain Taxonomy (AAAPT) Multidimensional Approach to Classifying Acute Pain Conditions.

Objective: With the increasing societal awareness of the prevalence and impact of acute pain, there is a need to develop an acute pain classification system that both reflects contemporary mechanistic insights and helps guide future research and treatment. Existing classifications of acute pain conditions are limiting, with a predominant focus on the sensory experience (eg, pain intensity) and pharmacologic consumption. Consequently, there is a need to more broadly characterize and classify the multidimensional experience of acute pain.

The ACTTION-APS-AAPM Pain Taxonomy (AAAPT) Multidimensional Approach to Classifying Acute Pain Conditions.

Objective: With the increasing societal awareness of the prevalence and impact of acute pain, there is a need to develop an acute pain classification system that both reflects contemporary mechanistic insights and helps guide future research and treatment. Existing classifications of acute pain conditions are limiting, with a predominant focus on the sensory experience (e.g.

Pain-Related Limitations in Daily Activities Following Thoracic Surgery in a United States Population.

Background: Ringsted et al created a statistically validated questionnaire to assess pain-related limitations in daily activities following thoracic surgery and translated it to English. We utilized the questionnaire to assess the impact of pain impairing certain daily activities in a United States thoracic surgery population.

Objectives: Examine if the questionnaire developed and translated to English by Ringsted et al to assess the effects of chronic pain after thoracic surgery on daily activities would be applicable in a sample of thoracic surgery patients in the United States.

A Prospective Study of Chronic Pain after Thoracic Surgery.

Background: The goal of this study was to detect the predictors of chronic pain at 6 months after thoracic surgery from a comprehensive evaluation of demographic, psychosocial, and surgical factors.

Methods: Thoracic surgery patients were enrolled 1 week before surgery and followed up 6 months postsurgery in this prospective, observational study. Comprehensive psychosocial measurements were assessed before surgery.

Muscle Reactive Oxygen Species (ROS) Contribute to Post-Incisional Guarding via the TRPA1 Receptor.

Background: Deep tissues and their afferents have unique responses to various stimuli and respond to injury distinctively. However, the types of receptors and endogenous ligands that have a key role in pain after deep tissue incision are unknown. TRPA1 has been shown to mediate pain-related responses in inflammation- and nerve injury-induced pain models.

Research Gaps in Practice Guidelines for Acute Postoperative Pain Management in Adults: Findings From a Review of the Evidence for an American Pain Society Clinical Practice Guideline.

Unlabelled: Acute postoperative pain is a common clinical condition that, when poorly controlled, can result in a number of significant negative consequences. The American Pain Society commissioned an evidence-based guideline on the management of postoperative pain to promote evidence-based, safe, and effective perioperative pain management. An interdisciplinary panel developed 31 key questions and inclusion criteria to guide the evidence review.

Comparison of Conventional and Kilohertz Frequency Epidural Stimulation in Patients Undergoing Trialing for Spinal Cord Stimulation: Clinical Considerations.

Objective: Compare therapeutic response of patients to conventional versus high-frequency spinal cord stimulation (SCS).

Methods: Twelve patients with back and leg pain who met standard clinical criteria for a trial of conventional SCS (low-frequency stimulation [LFS]) participated in a half-day session of high-frequency stimulation (HFS) during their weeklong conventional trial. HFS consisted of frequencies ranging from 50 Hz to 4 kHz, or 100 Hz to10 kHz, at constant voltage settings increasing from 0.

Conditioned place preference and spontaneous dorsal horn neuron activity in chronic constriction injury model in rats.

Patients with neuropathic pain commonly present with spontaneous pain, in addition to allodynia and hyperalgesia. Although evoked responses in neuropathic pain models are well characterized, determining the presence of spontaneous pain is more challenging. We determined whether the chronic constriction injury (CCI) model could be used to measure effects of treatment of spontaneous pain, by evaluating dorsal horn neuron (DHN) spontaneous activity and spontaneous pain-related behaviors.

A Comparison of 2 Ultrasound-Guided Approaches to the Saphenous Nerve Block: Adductor Canal Versus Distal Transsartorial: A Prospective, Randomized, Blinded, Noninferiority Trial.

Background And Objectives: Saphenous nerve blocks can be technically challenging. Recently described ultrasound techniques have improved the success rate of saphenous nerve blocks, but randomized controlled trials comparing these ultrasound-guided techniques are lacking. We compared 2 common ultrasound-guided approaches for saphenous nerve block: saphenous nerve block at the adductor canal (ACSNB) versus block by the distal transsartorial (DTSNB) approach.

Incidence and severity of chronic pain at 3 and 6 months after thoracotomy: meta-analysis.

Unlabelled: This systematic review was performed to determine the incidence and the severity of chronic pain at 3 and 6 months after thoracotomy based on meta-analyses. We conducted MEDLINE, Web of Science, and Google Scholar searches of databases and references for English articles; 858 articles were reviewed. Meta-regression analysis based on the publication year was used to examine if the chronic pain rates changed over time.

Single intrathecal administration of the transcription factor decoy AYX1 prevents acute and chronic pain after incisional, inflammatory, or neuropathic injury.

The persistence of pain after surgery increases the recovery interval from surgery to a normal quality of life. AYX1 is a DNA-decoy drug candidate designed to prevent post-surgical pain following a single intrathecal injection. Tissue injury causes a transient activation of the transcription factor EGR1 in the dorsal root ganglia-dorsal horn network, which then triggers changes in gene expression that induce neuronal hypersensitivity.