Investigating Cannabis Use Parameters on Anesthesia and Inflammation in Lumbar Spinal Surgeries

Summary

Cannabis is the most commonly used illicit drug in the United States with reported rates of use increasing from approximately 50 million in 2020 to 61.8 million in 2023 among individuals aged 12 or older. This rise can be attributed to a combination of growing social acceptance and expanding legalization for recreational and medical use of cannabis. Consequently, this has led to increased commercially available cannabis products with heterogeneous concentrations of cannabinoids (i.e., THC:CBD ratios) and new methods of administration becoming more available (e.g., vaping and gummies). Taken together, this rapidly shifting landscape further contributes to the significant variability in individual use patterns (i.e., frequency, duration, and route of administration) resulting in diverse clinical responses, which poses significant challenges for anesthetic management. Recent systematic reviews and meta-analysis have quantitatively demonstrated that cannabis users require higher dosages during anesthesia induction, experience greater hemodynamic instability, and report higher opioid consumption and pain scores post-operatively. These findings have led to the prevailing notion that cannabis exposure adversely affect anesthetic management. Yet, key cannabis exposure parameters in individual use patterns (i.e., variations in THC:CBD ratios, route of administration, frequency, and duration of use) remain poorly characterized and could confound observed clinical effects in relation to their effects on pain modulation and anesthetic requirements. Current perioperative assessments do not account for these critical variables, creating a gap that limits the development of more accurate and personalized anesthetic protocols. Failure to account for individual cannabis exposure parameters may lead to inappropriate anesthetic dosing - where underdosing could result in intraoperative awareness, pain, or patient movement, while overdosing might cause cardiovascular depression, respiratory failure, or prolonged recovery from anesthesia. Concomitantly, researchers have discovered that cannabis consumption modulates immune function such that early life exposure to cannabis produces a long-lasting and persistent inflammatory state characterized by reduced serum levels of IL-6, TNF-α, and IL-2. In contrast, recent research demonstrates that cannabinoid exposure improves skin healing in patients with cutaneous disorders. However, the effects of altered inflammatory responses, and the diverse actions of various cannabinoids on postoperative wound healing remain largely unexplored. Our long-term goal is to elucidate the mechanistic impact of chronic cannabis use parameters on anesthetic and analgesic requirements, thereby enabling the development of personalized, evidence-based perioperative management strategies. The investigators hypothesize that chronic cannabis exposure leads to impaired endogenous pain and immune modulation, resulting in increased intraoperative anesthetic dosing, heightened hemodynamic variability, and elevated postoperative pain and inflammation.