Combined spinal and epidural anaesthesia

Combined spinal and epidural anaesthesia is a regional anaesthetic technique, which combines the benefits of both spinal anaesthesia and epidural anaesthesia and analgesia. The spinal component gives a rapid onset of a predictable block. The indwelling epidural catheter gives the ability to provide long lasting analgesia and to titrate the dose given to the desired effect. This technique also allows for better post operative pain relief. The epidural catheter may be left in place for up to 72 hours if required. In labouring women, the onset of analgesia is more rapid with combined spinal and epidural anaesthesia compared with epidural analgesia. Combined spinal and epidural anaesthesia in labour was formerly thought to enable women to mobilise for longer compared with epidural analgesia, but this is not supported by a recent Cochrane review. In the UK, the National Institute for Health and Care Excellence (September 2007) recommends combined spinal and epidural anaesthesia for women who require rapid onset of analgesia in labour. It further recommends the use of bupivacaine and fentanyl to establish the block. Combined spinal-epidural anaesthesia is a highly specialised technique which should only be administered by a properly trained anaesthetic practitioner working with full aseptic technique. The needle-through-needle technique involves the introduction of a Tuohy needle (epidural needle) into the epidural space. The standard technique of loss of resistance to injection may be employed. A long fine spinal needle (25G) is then introduced via the lumen of the epidural needle and through the dura mater, into the subarachnoid space. A small pop is felt as the dura is punctured, and the correct position is confirmed when cerebrospinal fluid can be seen dripping from the spinal needle. A small dose of local anaesthetic (e.g. bupivacaine) is then instilled. An opioid such as fentanyl may also be given if desired. The spinal needle is then withdrawn and the epidural catheter inserted in the standard manner.