An epidural anaesthetic is very similar to a spinal anaesthetic, but the injection into the back does not penetrate as deeply and does not enter the cerebrospinal fluid. The spinal cord is wrapped in three layers of fibrous material (the meninges), and this anaesthetic is given into the very small space between the outer two layers (dura mater and arachnoid mater). It is outside the dura – thus epidural. The procedure is technically more difficult than a spinal anaesthetic, but the side effects are less severe. Epidural anaesthetics are used most commonly to relieve the pain of childbirth.