ABSTRACT
Thoracic epidural analgesia can effectively relieve post-thoracotomy pain but may also adversely affect pulmonary function. This randomised, prospective study compared the effects on pulmonary function of three different epidural analgesics (clonidine, bupivacaine and methadone). Forty-seven patients undergoing thoracotomy were treated postoperatively for 72 h with one of the study drugs. Doses were titrated to maintain visual analogue pain scale values below 4 out of 10. Throughout the postoperative period, reductions of up to 70% of the pre-operative value were observed in forced expiratory volume in 1 s, forced vital capacity and peak expiratory flow rate. Patients who received clonidine showed significantly faster recovery rates of forced expiratory variables compared to other patients, and by the third postoperative day significantly higher spirometry values (10-15%) were recorded in this group. As clonidine was the most effective drug in terms of preservation of pre-operative lung function, it may be clinically advantageous in post-thoracotomy patients.
