Dysaesthesia associated with sternotomy for heart surgery

Background. Chronic pain occurs in 40-50% patients following cardiac surgery. Dysaesthesia, either in the form of heightened or diminished skin sensation, are frequently associated with chronic neuropathic pain. Therefore, dysaesthesia in the early postoperative period may predict chronic pain. However, the character and causes of dysaesthesia in the early postoperative period are unknown. The aim of this study was to investigate the incidence, extent, and causes of dysaesthesia following cardiac surgery by sternotomy. Methods. In a prospective cohort study, 50 patients undergoing sternotomy for cardiac surgery were admitted to the study: 38 underwent coronary artery bypass graft (CABG), nine valve surgery, and three combined surgery. Forty-eight hours postoperatively, acute pain was measured by four-point verbal scale. Manual pinprick and cotton wool brushing was used to detect the areas of dysaesthesia. Results. Some form of dysaesthesia was found in 27 (54%) of the patients. Using multivariate regression analysis, the total area of dysaesthesia was positively associated with CABG surgery and the severity of postoperative pain (P < 0.001). Conclusion. Dysaesthesia is common in the early postoperative period following cardiac surgery using a sternotomy and is associated with CABG surgery. The association with severity of pain may indicate a neuropathic element that is unrelieved by conventional opioid analgesia.