Sensory Outcomes in Active Substance Users

The incidence and severity of postoperative pain after spine surgery are notably high, often requiring intensive management and potentially affecting the patient's recovery, satisfaction, and long-term outcomes. Post-operative pain is particularly difficult to manage in patients with substance use disorder likely due to a combination of withdrawal symptoms and molecular changes in the pain matrix. Opiates are the leading cause of overdose related fatalities, and carry a significant burden of substance related morbidity and mortality. As over 80% of patients undergoing low-risk surgery receive opioid prescriptions, the investigators aim to identify unique molecular characteristics of pain within current and previous opioid users, which have been understudied in this context. This study also seeks to understand the molecular mechanisms underlying worsened postoperative pain in patients with opioid use disorder (OUD).

Flow cytometry analysis of human serum will be done, which will assess circulating immune cells that can contribute to exacerbated surgery site inflammation. Spatial profiling of gene expression will be done in the dermis using Visium slide sequencing, focusing on the interplay between nerve endings, resident immune cells, and supporting dermal cells, all of which collectively contribute to the sensation pain. Both the visual pain rating scale and McGill Pain Questionnaire will be used to comprehensively quantify pain outcomes during the participant's postoperative recovery stay after surgery in an effort to better understand postoperative pain management with biomarkers of worsened postoperative pain.