The Impact of Tobacco Smoking on Spinal Cord Stimulation Effectiveness in Complex Regional Pain Syndrome Patients.

OBJECTIVES: We aim to investigate the correlation of smoking and spinal cord stimulation (SCS) effectiveness for pain relief in complex regional pain syndrome (CRPS) patients while controlling for possible confounding factors including opioid intake. MATERIALS AND METHODS: Following Institutional Review Board approval, a retrospective cohort study was performed by collecting data for all CRPS patients treated with SCS at Cleveland Clinic between 1998 and 2013. We divided patients into three groups based on their smoking status at the time of SCS device implant: Current smokers, former smokers, or nonsmokers. We used a linear mixed modeling to assess the association between smoking status and pain score at baseline and at 3, 6, and 12 months. We then used pairwise t-tests for post hoc comparisons of pain scores. RESULTS: Of the 420 CRPS patients treated with SCS implants, the reduction in pain score was highest among nonsmokers. Nonsmokers demonstrated a consistent and steady decrease in pain scores over time, whereas the current and former smoker cohorts showed an initial reduction in pain at three months compared to baseline which was not sustained to the 12-months benchmark. Nonetheless, former smokers continued to report slightly lower pain scores than current smokers, although not statistically significant. The baseline opioid consumption was least among nonsmokers (30 [0, 62] oral mg morphine sulfate equivalent). We also found a statistically significant association between time postimplant and reported pain score (χ2 = 508.88, p < 0.001). The overall mean pain score for all three cohorts was highest at baseline (7.6 ± 1.7) and showed a decrease at the 3, 6, and 12 months postimplant time points with mean score of 5.7 ± 2.0, 5.6 ± 2.3, and 5.4 ± 2.5, respectively. CONCLUSION: Tobacco cigarette smoking was associated with reduced SCS effectiveness for pain relief.