This technique also allows for post operative pain relief via epidural patient controlled anesthesia. 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 CSE compared with epidural analgesia. CSE 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 Clinical Excellence (September 2007) specifically recommends CSE for women who require rapid onset of analgesia in labour It further recommends the use of bupivacaine and fentanyl to establish the block.
Cautions and contraindications are very similar to those for epidural anaesthesia.
Practitioners who make frequent use of the CSE technique for labor analgesia may note unexpected benefits. One example is in the event that the epidural catheter is unintentionally placed into a blood vessel. This requires removal of the catheter and its replacement. With the traditional technique of epidural placement, the patient continues in pain without relief. If the CSE technique has been used, the intrathecal injection of fentanyl results in 60 to 90 minutes of good pain relief. This creates a more pleasant environment in which to replace the errant catheter with a properly sited one.
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 The spinal needle is then withdrawn and the epidural catheter inserted in the standard manner.
Alternatively, a two-level approach may be undertaken. The epidural space is first located in the standard manner. Then, at another level, a standard spinal is performed. Finally, the epidural catheter is threaded through the Tuohy needle.
Alternatively, several manufacturers produce packs containing both a spinal and an epidural needle which are slightly modified to fit together.
CSE in labouring women is associated with more pruritis if fentanyl (25μg) is given intrathecally, than low-dose epidural analgesia. However, no difference has been found in the incidence of post dural puncture headache, requirement for epidural blood patch or maternal hypotension.