The Daily Dose • Monday, March 21, 2022
The Roots of Chronic Postoperative Pain: Personalized Prevention and Treatment for Patients at Risk
Although nearly all surgical patients experience acute postoperative pain, only about 30% go on to develop chronic postoperative pain, with varying degrees of severity. What puts certain patients at greater risk of “chronification?” Four experts — Kristin Schreiber, MD, PhD, Andrea Chadwick, MD, Jeanna Blitz, MD, and Jennifer Hah, MD, MS — led a dynamic session, “Preventing Chronic Postsurgical Pain and Opioid Use: From Mechanistic Basis Under the Biopsychosocial Model to Practical Preoperative Assessment, Phenotyping, and Intervention” on Sunday, March 20, at the IARS 2022 Annual Meeting. They provided a comprehensive overview of the perioperative trajectory for patients at risk for chronic pain. Key topics discussed included the biopsychosocial model of pain, the centralized pain phenotype, preoperative risk assessment and prehabilitation, and postoperative opioid misuse.
Kristin Schreiber, MD, PhD, Neuroscientist and Clinical Regional Anesthesiologist at Brigham and Women’s Hospital, and Associate Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Harvard Medical School, began the session with “The Biopsychosocial Model of Pain and Phenotypic Assessment.” During her presentation, Dr. Schreiber analyzed the “pathophysiological plasticity” that underlies the transition from acute to chronic postsurgical pain. She described the influence of patients’ psychosocial and biophysical phenotypes on chronic pain risk after an acute injury (Schreiber 2013, Schreiber 2014, Belfer 2013). She also highlighted her work in preoperative measurement of these phenotypes (via questionnaires or quantitative sensory tests; identification of risk factors for chronic postsurgical pain; and stratification of patients by pain phenotype to determine the relative efficacy of specific preventive interventions (Schreiber 2021). Dr. Schreiber concluded her presentation by emphasizing the importance of personalizing both pain prevention and treatment based on phenotypic evidence of each patient’s relative risk for persistent pain.
Andrea L. Chadwick, MD, MSc, FASA, Associate Professor in the Department of Anesthesiology, Pain and Perioperative Medicine at the University of Kansas School of Medicine, then spoke on “Mechanisms of Chronic Postsurgical Pain.” She highlighted the mechanisms underlying central sensitization, which can occur either in the presence or absence of peripheral injury (Kehlet 2006). Dr. Chadwick described both qualitative and quantitative assessment to identify preoperatively the presence of a centralized pain phenotype, which places patients at risk of significant postoperative pain. Her presentation was unique in its discussion of neuroimaging (e.g., functional MRI) to detect a patient’s propensity for developing chronic postsurgical pain.
Jeanna Blitz, MD, FASA, Associate Professor of Anesthesiology at Duke University School of Medicine, then presented on “Psychological Preparation for Surgery: A Pragmatic Approach.” She discussed the proinflammatory effect of depression and anxiety and expressed her belief that psychological preparation is the most important aspect of patient prehabilitation. Dr. Blitz also discussed common tools for identifying patients at risk for perioperative psychological distress and recommended several potential interventions (Powell 2016, Carter 2018). At the conclusion of her talk, Dr. Blitz echoed the other panelists’ belief in the importance of preoperative screening and intervention to improve postoperative outcomes.
Jennifer Hah, MD, MS, Assistant Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, spoke on “Assessment and Prevention of Persistent Opioid Use After Surgery.” She briefly discussed the opioid epidemic and then provided evidence for an association between persistent postoperative opioid use and the development of both opioid use disorder and drug overdose (Aalberg 2022). She highlighted risk factors for persistent opioid use after surgery (Larach 2022) and identified the worst pain level on postoperative day 10 as the best predictor of persistent postoperative opioid use (Hah 2019). Dr. Hah also emphasized the importance of preoperative preparation of patients in setting appropriate expectations and tapering opioid doses as tolerated (Wetzel 2018). She recommended more judicious prescribing of opioids postoperatively, followed by a guided opioid taper (Hah 2020). Dr. Hah concluded her talk by upholding the value of a multidisciplinary pain team and the importance of moderating perioperative opioid use whenever possible.
Dr. Schreiber then moderated an energetic Q&A discussion that discussed a wide variety of themes: intraoperative opioid administration, ketamine for the prevention of central sensitization, and cultural, ethnic, and gender influences on pain phenotypes.