[Comparison between fentanyl and a fentanyl-bupivacaine combination using epidural PCA for postoperative analgesia after thoracotomy].

HYPOTHESIS

The association of opioids and local anesthetics for spinal analgesia appears to have a synergistic++ effect.

OBJECTIVE

To compare the efficacy of fentanyl in comparison with combined fentanyl and bupivacaine at low concentrations in a thoracic epidural system of patient-controlled analgesia (PCA) following thoracotomy.

PATIENTS AND METHODS

Twenty male patients scheduled for thoracotomy by postero-lateral (T5-T6) incision received analgesia after surgery through a thoracic (T4-T8) epidural catheter connected to a PCA pump (continuous infusion and boluses). They were randomly assigned to 2 groups as follows: group A (n = 10) received a baseline infusion of fentanyl 1 microgram/kg/h and bupivacaine 0.125% with boluses of 12.5 micrograms fentanyl and bupivacaine at 0.125%. The variables studied were: score on a visual analog scale (VAS) before treatment and at 12 and 24 h; the number of boluses administered through the PCA pump, forced vital capacity (FVC) and peak expiratory flow (PEF) before treatment and at 12 h.

RESULTS

Analgesia was satisfactory in both groups, with no significant differences in VAS and number of boluses administered. Nor were there significant differences in lung function tests. One instance of respiratory depression was recorded in group A.

CONCLUSIONS

The analgesic effect obtained with epidural fentanyl or fentanyl/bupivacaine is similar and adequate, and the association of fentanyl and bupivacaine can be considered safe.