A prospective, randomized comparison of preoperative and continuous balanced epidural or paravertebral bupivacaine on post-thoracotomy pain, pulmonary function and stress responses

Both epidural and paravertebral blocks are effective in controlling post-th oracotomy pain, but comparison of preoperative and balanced techniques, mea suring pulmonary function and stress responses, has not been undertaken pre viously. We studied 100 adult patients, premedicated with morphine and dicl ofenac, allocated randomly to receive thoracic epidural bupivacaine or thor acic paravertebral bupivacaine as preoperative bolus doses followed by cont inuous infusions. All patients also received diclofenac and patient-control led morphine. Significantly lower visual analogue pain scores at rest and o n coughing were found in the paravertebral group and patient-controlled mor phine requirements were less. Pulmonary function was significantly better p reserved in the paravertebral group who had higher oxygen saturations and l ess postoperative respiratory morbidity. There was a significant increase i n plasma concentrations of cortisol from baseline in both the epidural and paravertebral groups and in plasma glucose concentrations in the epidural g roup, but no significant change from baseline in plasma glucose in the para vertebral group. Areas under the plasma concentration vs time curves for co rtisol and glucose were significantly lower in the paravertebral groups. Si de effects, especially nausea, vomiting and hypotension, were troublesome o nly in the epidural group. We conclude that with these regimens, paraverteb ral block was superior to epidural bupivacaine.