Impact of different doses of remifentanil on chronic postsurgical pain after video-assisted thoracic surgery: A propensity score analysis.

A remifentanil infusion dose of >0.2 μg/kg/min is associated with hyperalgesia, leading to acute postsurgical pain; however, its contribution to the development of chronic postsurgical pain after video-assisted thoracic surgery remains unclear. This study aimed to evaluate the impact of different remifentanil doses on chronic postsurgical pain after video-assisted thoracic surgery. This study included inpatients aged ≥ 55 years who underwent video-assisted thoracic surgery under general anesthesia between April 2016 and December 2018. An inverse probability of treatment weighted using stabilized inverse propensity scores was adopted to minimize bias. After adjustments based on patient data, the outcomes of interest were compared with intraoperative covariates using a generalized estimating equation. The primary study outcome was chronic postsurgical pain 1 year after surgery, defined as a pain score ≥1 on a numerical rating scale. Of the 262 eligible patients, 258 with a mean age of 71.2 years were included in this analysis. Chronic postsurgical pain occurred in 23.6% of patients. The generalized estimating equation revealed that a remifentanil infusion dose >0.2 μg/kg/min was associated with chronic postsurgical pain at 1 year after surgery (odds ratio [OR] 1.52; 95% confidence interval [CI] 1.03-2.27), while remifentanil infusion doses >0.15 μg/kg/min (OR 1.12; 95% CI 0.79-1.59) and >0.175 μg/kg/min (OR 1.17; 95% CI 0.83-1.64) were not associated with our primary outcome. Remifentanil infusions >0.2 μg/kg/min were associated with chronic postsurgical pain 1 year after video-assisted thoracic surgery.