Unlike spinals, epidurals are usually combined with general anaesthesia. Reasons include:

• Epidural anaesthesia may not produce such a dense or predictable block as a spinal
• Surgical manipulation of abdominal organs can still be distressingly uncomfortable even with a good epidural, as the vagus nerve still remains unblocked

Another important difference is that epidurals, unlike spinals, may have a lower limit of block. This is especially so for those placed at higher levels. This can limit the usefulness of the technique.