Major conduction blocks utilizing local anesthetics or opiates are find ing ever increasing applications in daily routine. However, two serious drawbacks are associated with their use: hypotension during surgery and the development of tolerance in long-term epidural analgesia. When opiates are injected epidurally or intrathecally, numerous side effects such as itching, nausea and vomiting, or respiratory depression have been reported. The pathophysiology of complications arising during a major conduction block and measures to prevent them were discussed by 19 experts at the 4th International...