Perineuronal morphine in intercostal block.

In a double-blind, randomised study the potential benefits of combining low-dose morphine with bupivacaine for intercostal nerve blocks for analgesia after biliary surgery were investigated. There was no significant improvement in pain scores or consumption of supplementary analgesics when morphine was added to bupivacaine. This investigation supports the findings of other workers who showed that perineural morphine was ineffective for postoperative pain relief.