Post-thoracotomy spirometric lung function: the effect of analgesia. A review

The effects of postthoracotomy pain management on pulmonary function has been assessed.

All English language publications involving prospective, randomised, controlled studies of patients undergoing postero-lateral thoracotomy incisions where perioperative spirometry had been studied were included. The mean postoperative percentage preservation of preoperative lung function was recorded or determined for each analgesic regimen.

55 studies were reviewed with a total of 1762 patients. The most effective analgesic method in terms of preservation of spirometric function was paravertebral analgesia, patients having approximately 75% of their preoperative values in the first 48 hours after surgery. Most other techniques e.g. intercostal nerve blocks, epidural local anaesthetics or local anaesthetic-opiate combinations produced approximately a 55% preservation by 48 hours. Interpleural analgesia was the least effective, with a mean of 35% preservation by 48 hours, less even than TENS or cryoanalgesia.

A thoracotomy potentially produces a marked reduction in postoperative pulmonary function and the choice of pain management has major implications. Attenuation of postthoracotomy pulmonary dysfunction by effective analgesia should be provided for all patients undergoing chest surgery. Simply providing effective analgesia on its own without regard to pulmonary function is inadequate. Spirometric monitoring should be standard in all thoracic units and is essential for objective comparisons of the efficacy of different methods of pain management.