The purpose of this study was to investigate the effect of different pain-relief methods (regional and systemic) following thoracotomies on the cardiovascular system, pulmonary gas exchange, various endocrine parameters and subjective perception. A further aspect was to evaluate the benefits of interpleural analgesia as a new regional technique against already established regional techniques, such as intercostal nerve block and thoracic epidural block. All postoperative pain methods led to a significant time-dependent reduction of the adrenaline concentrations in plasma while the noradrenaline concentrations did not change significantly. There were no statistical differences in catecholamine concentrations among the different study groups, although the mean concentrations of adrenaline in patients having a thoracic epidural block for pain relief were lower in comparison to the findings in other groups. The plasma concentrations of the "stress metabolites", such as glucose, free fatty acids and lactate, as well as the haemodynamic (mean arterial pressure, heart rate) and pulmonary parameters (blood gas analyses), showed no significant differences among groups. In contrast to the other pain-relieving methods, interpleural analgesia did not lead to sufficient pain relief in that 7 out of 10 patients needed supplementary systemic opioid therapy. Therefore, interpleural analgesia for pain relief following thoracotomies cannot be recommended.

Compared with general anesthesia and postoperative IV patient-controlled analgesia with morphine, epidural anesthesia and analgesia with the new local anesthetic ropivacaine enables patients to be discharged sooner from a postanesthesia care unit and provides superior pain relief during the first 24 h after hip replacement.