Interpleural administration of bupivacaine for postoperative analgesia after thoracotomy in patients with patent ductus arteriosus.

Interpleural analgesia for postoperative pain with bupivacaine 0.25%, 0.375% and 0.5% at dosage of 1.5 mg/kg was evaluated in three randomized groups (A, B and C) of 22 children having triple ligation for patent ductus arteriosus (PDA). Complete pain relief was obtained within 30 min irrespective of the concentration of bupivacaine. The duration of pain relief significantly varied with the concentrations of the drug used, respectively 5.02 +/- 0.4 h, 6.88 +/- 0.7 h and 8.24 +/- 1.08 h (mean +/- SD) for 0.25%, 0.375% and 0.5% bupivacaine (p less than 0.05). No side effects were observed and no other supplemented narcotics were given. We concluded that 0.5% bupivacaine at the dose of 1.5 mg/kg was effective in postoperative pain relief after thoracotomy in patients undergoing PDA ligation surgery.