Analgesia in thoracic surgery: review

Post-thoracotomy pain is one of the most severe types of postoperative pain. It can last up to 2 months and can become chronic in 30% of patients. Pain relief after thoracic surgery is of particular significance, not only for ethical considerations but also for reduction of postoperative pulmonary and cardiac complications. Because of the difficulty in pain control, many approaches have been suggested, but a multimodal therapeutic strategy that provides a central or peripheral block associated with nonsteroideal anti-inflammatory (NSAID) and adjuvant drugs is now the cornerstone of treatment, offering the possibility of reducing opioid requirements and side effects. Thoracic epidural analgesia with local anesthetics and opioids is regarded as the gold standard treatment for post-thoracotomy pain management because it results in early extubation, better ventilatory mechanisms and gas exchange, decreased incidence of atelectasis, pneumonia and chronic postoperative pain. When epidural analgesia is contraindicated or cannot be performed, other regional techniques of analgesia can be used. An alternative method of providing adequate pain relief is a thoracic paravertebral block: continuous paravertebral infusion of local anesthetic via a catheter placed percutaneously or under direct vision during thoracotomy. This is effective in controlling postoperative pain and in preserving pulmonary function. Other techniques, such as intercostal and interpleural blocks, are rarely utilized, whereas a single shot of intrathecal injection of a hydrophilic opioid, such as morphine, appears to be effective. Cryoanalgesia, which is successful in the immediate postoperative period, has been abandoned for its brief duration and increased incidence of chronic pain.