Thoracic epidural for post-thoracotomy pain: a comparison of three concentrations of sufentanil in bupivacaine

Background: The aim of this prospective, double blind, randomised trial was to compare the analgesic and adverse effects of three concentrations of the thoracic epidural sufentanil with bupivacaine in patients undergoing thoracotomy. Methods: We studied 60 (randomised) patients who were to receive a 10 ml bolus dose of sufentanil, 1 mu g/ml, 2 mu g/ml and 3 mu g/ml, in bupivacaine 0.125%, via thoracic epidural. Postoperatively, pain at rest, on coughing and with ambulation was assessed using a visual analogue scale (VAS) and observer verbal ranking score (OVRS) at 2, 6, 12 and 24 hours. Adverse effects were simultaneously assessed. Results: There was no significant difference in the baseline characteristics between the three groups. The number of patients with episodes of unsatisfactory pain, i.e. a VAS scores >= 40 and OVRS >= 2, at each of the four assessments postoperatively, was significantly higher with sufentanil 1 g/ml than with sufentanil 2 mu g/ml or mu 3 g/ml (p < 0.05). In the 3 mu g/ml sufentanil group, four patients (20%) had a sedation score mu 3 compared with one (5%) and no (0%) patients in the 2 mu g/ml and 1 mu g/ml sufentanil groups, respectively (p < 0.05). In addition, 30% patients experienced pruritus in the 3 mu g/ml sufentanil group compared with 10% and 5%, respectively, in the 2 mu g/ml and 1 mu g/ml sufentanil groups. In the sufentanil 3 mu g/ml, 2 mu g/ml and 1 mu g/ml groups, 30%, 20% and 5% patients, respectively, had emetics symptoms (p < 0.05). Conclusions: We conclude that a thoracic epidural bolus of 10 ml sufentanil 2 mu g/ml with bupivacaine 0.125% provides the optimal balance between pain relief and side-effects following thoracotomy.