Chronic postoperative pain syndrome and its neuropathic component in long-term period of coronary artery bypass grafting

Abstract

Background: Along with increased safety and quality of the early postoperative period, 6.9% of patients who undergo sternotomy experience chronic pain at the surgical site. The significance of this issue is underestimated, with a third of these patients developing a neuropathic component of chronic pain syndrome. Aim: To assess the severity of acute and chronic postoperative pain following sternotomy and to identify predictors of the neuropathic component of chronic pain syndrome. Materials and methods: Out of 115patients who underwent elective coronary artery bypass grafting (CABG) randomized according to method of anesthesia, two study groups were formed based on the results of a telephone survey: a general anesthesia group (GA, n=28) and a combined anesthesia group (CA, n=34). As part of the posthoc analysis, a logistic regression model was built to predict chronic neuropathic pain syndrome based on gender, age, anesthesia method, and factors assessing the severity of the perioperative period and myocardial impairment. Results: Chronic postoperative pain syndrome was identified in 25.8% of patients, with a neuropathic component confirmed in 19.4% of cases. Pain severity at rest in the GA and CA groups was 2.0 (1.0) and 3.0 (3.0) points on a numeric rating scale one hour after extubation, and 2.0 (2.0) and 2.0 (2.0) points by the end of the first postoperative day (p=0.193 and 0.610, respectively). The logistic regression model achieved an AUROC of 0,82 (95% CI 0,68–0,96) with c2(10)=10.62, p=0.39. Conclusions: Neuropathic pain was diagnosed in 19.4% of patients following CABG. The use of regional anesthesia and the severity of acute pain did not impact the development of neuropathic pain syndrome in the long-term period after surgery. The proposed model for predicting the neuropathic component of chronic pain syndrome after CABG requires further improvement.