Obtundation of surgical stimulus

If an effective epidural is in situ during surgery, it will obtund the patient’s physiological response to surgery. This leads to little or no endogenous catecholamine release, which reduces the resultant cardiovascular stress.

Additionally, obtunding the surgical stimulus may make it possible to use a lower dose of general anaesthetic, with subsequently more rapid wakening at the end of the procedure.

Similarly, the lack of stimulus may enable the anaesthetist to avoid repeat doses of relaxant drugs, with consequently no need to use reversal agents, thus avoiding their side-effects.

Pain-free wakening/recovery

As with spinal anaesthesia, an effective epidural allows a patient to enjoy pain-free wakening from general anaesthesia after even the most extensive of surgery, and to enjoy a pain free-recovery.

Prolongable duration of block

Because the epidural catheter remains in situ, the duration of block can be extended, unlike the block of a spinal.

Awake patient/avoids general anaesthesia

Although epidurals are most commonly used in combination with general anaesthesia, they can be used as the sole means of anaesthesia in some circumstances, most commonly in obstetric patients with existing labour epidurals who require surgery.

Improved surgical field/reduced blood loss

The hypotension produced by epidural anaesthesia can reduce the amount of blood loss at the surgical site, with benefits for the surgeon and patient.

Reduced DVT risk

The reduction in systemic vascular resistance results in increased flow to the lower limbs, reducing venous stasis, and thus reducing DVT risk.

Benefits in respiratory and cardiovascular disease

These benefits are similar to those found in spinal anaesthesia.

However, because an epidural can be continued after surgery, these benefits can be continued as well.

For instance, by allowing pain-free respiration, coughing and physiotherapy, an epidural can significantly reduce the risk of post-operative respiratory complications in susceptible patients.

In mild or well-controlled disease, the use of epidural anaesthesia is unlikely to be associated with a measurable difference in morbidity or mortality.