Chronic postoperative pain in cardiac surgery: analysis of quantitative sensory testing and pain history data

Objective. To analyze neurophysiological profile (thresholds of temperature sensitivity and pain, pain pressure threshold), algological profile (pre-existing pain history, pain in early postoperative period, central sensitization inventory data), as well as features of surgical intervention in patients who underwent cardiac and/or aortic surgery with and without chronic postoperative pain (CPP). Material and methods. The study included 100 patients who underwent cardiac and/or aortic surgery. All patients underwent quantitative sensory testing (QST) with thermal and pressure stimulation before surgery. Patients were also questioned regarding chronic pain and completed the central sensitization inventory. In early postoperative period, patients were questioned regarding severe pain syndrome (VAS score >6). In 3—6 months after surgery, patients were interviewed regarding CPP. According to these results, patients were divided into two groups: CPSP group (30 patients) and non-CPSP group (70 patients). Statistical analysis included t-test, non-parametric Mann–Whitney U-test and Spearman’s rank correlation coefficient. Results. CPP occurred in 30% of patients. Severe early postoperative pain was more common in patients with CPP compared to the control group (p=0.0001). There was association of central sensitization with CPP (p=0.002). No significant differences in QST data and surgery time were found. Conclusion. To minimize the risk of CPP and select therapy for chronic postoperative pain, clear understanding of mechanisms is necessary taking into account various aspects (psychological state, anamnestic data, sensitivity, features of sensory profile).