Nerve damage

Damage to one or more nerve roots can cause sensory or motor symptoms. Although these are usually transient, they can be permanent. The risk is very low, so accurate estimates are difficult to make. However, a recent study (Auroy et al, 2002) gives a risk of <1 per 10000 epidurals (peripheral neuropathy or cauda equina syndrome).

Paralysis

As with spinals, this is a rare complication. Again, based on the limited literature, a reasonable ‘best guess’ risk is <1 per 100000 epidurals (Horlocker & Wedel, 2000).

Epidural abscess

As with spinals, the risk of this complication is very low and is kept low by assiduous attention to asepsis: hat, mask, gown, gloves and appropriate skin preparation.

Epidural haematoma

As with spinals, this complication is most likely in patients with disordered coagulation, either iatrogenic or pathological.

Meningitis

As with spinals, risk of this complication can be decreased if assiduous attention is paid to asepsis: hat, mask, gown, gloves and appropriate skin preparation. In any case, it is an unlikely consequence if the dura are not breached.

Total spinal

There are two situations where this is a realistic possibility:

• An epidural catheter is accidentally inserted into or migrates into the subarachnoid space and this is unrecognized. An epidural dose of local anaesthetic is then given into the subarachnooid space
• A failed epidural dose of local anaesthetic is followed by a spinal anaesthetic, allowing the epidural drug to move into the subarachnoid space, most commonly seen when an epidural top-up for caesarean section provides inadequate anaesthesia