Techniques of epidural block

Epidural blocks can be performed at any level from the high cervical spine down to the sacral hiatus. A lumbar epidural can provide surgical anaesthesia and postoperative analgesia for sub-umbilical surgery, whereas a thoracic epidural will provide effective analgesia but not anaesthesia for thoracic and upper abdominal surgery. A single-shot bolus has a duration of 2-4 hours, using a long-acting local anaesthetic, but in the majority of cases prolonged postoperative analgesia is achieved by inserting an epidural catheter and infusing a dilute local anaesthetic and opioid drug combination. Although a useful regional anaesthetic technique with significant patient benefits, an epidural is an invasive procedure, can be technically difficult, and has the potential to cause serious adverse events (direct needle trauma to the spinal cord or the spinal nerve roots, vertebral canal haematoma and meningitis or epidural abscess) if not done to a high standard and managed appropriately. Epidural and caudal blockade have a number of synonyms, which can be confusing. The terms 'epidural' (extradural, peridural) and 'caudal' (sacral epidural) are used throughout this article.