“Tobacco Smoking is Associated with Analgesic Failure of Spinal Cord Stimulation"
Despite the observation that select nicotinic agonists possess analgesic effects, tobacco smokers consistently report higher pain-associated function impairments than non smokers. The mechanisms underlying chronic pain in tobacco smokers involves exaggerated stress responses, receptor desensitization and altered pharmacokinetics which are compounded by accelerated structural damage resulting from impaired bone healing, osteoporosis and advancement of intervertebral disc diseases. While tobacco smoking is known to heighten baseline pain, comparatively little is known about whether smoking predicts treatment failure of Spinal Cord Stimulator (SCS). We hypothesized that smoking diminishes the analgesic response to SCS expressed in high pain score and opioid consumption in patients with chronic spine-related pain conditions include post laminectomy syndrome and degenerative disc disease.
Following IRB approval, we assessed historical data from 213 consecutive patients from 1997 to 2013 who were implanted with SCS for spine-pain indications at our institution. All subjects had a successful trial of over 50% pain relief as evidence by improved functionality before permanent SCS implant. Tobacco use history was characterized as former, non or current smokers. Multivariate linear regression was utilized to assess correlation of tobacco smoking status and pain relief using Numerical Rank Scale [NRS] Pain Scores and opioid utilization in (mg oral morphine equivalents) at baseline and one year follow-up.
Current smokers represented 29.1% (n=62) of the study population, while former smokers were 34.7% (n=74) and non smokers totaled 36.2% (n=77). Baseline demographics data and other patient characteristics among three groups were adjusted for the analyses. At one year follow-up, current smokers reported NRS pain scores of 7.0; 1.9 (CI: 1.2-2.7, p<0.001) points higher than their non smokers counterparts and 1.32 (CI: 0.4-2.3, p=0.001) higher than former smokers, controlled for baseline pain scores and potential confounders. Mean opioid intake was 2.4 mg higher (CI: 1.2-4.9, p<0.001) in smokers than non smokers.
Among patients with spine pain related diagnoses implanted with SCS, we observed a correlation between tobacco use and progression to eventual analgesic failure at 12 months following SCS implant as evidence by high pain score and opioid use in current smokers in compare to former and never smokers.
Interestingly, former smokers did not exhibit worse pain score than never smokers. While not intended to be considered in isolation, this observation may warrant appraisal as part of a larger cohort of factors the implanter is considering when evaluating a patient’s candidacy for SCS therapy.