Advantages of the combined spinal epidural (CSE) technique: a reply

Thank you for giving us the opportunity to reply to Drs Olufolabi and Booth, and Drs Norman and Plaat. Undoubtedly, an intrathecal dose of a mixture will have a more rapid and complete onset than an equivalent epidural dose. However, data from a study by Dr Plaat and others at the same institution indicate that an epidural will provide good analgesia by 20 min [1, 2], and by 5 min is starting to take effect. Our patients were all in early established labour and we felt that this was a reasonable time-scale. Obviously, in later labour and for situations such as those indicated by Drs Olufolabi and Booth rapidity of onset may be useful. Meningitis with the CSE has been the subject of a further case report since we wrote our paper [3]. Both correspondents are justified in saying that we are unable to quantify the risk. However, any new technique requires evaluation. Meningitis must be a concern when the dura is breached and a catheter is left in situ in the adjacent epidural space. Although the risk appears to be small, meningitis is the cause of major morbidity. Few institutions currently permit midwives to give top-ups containing fentanyl at all [4], not withstanding a first epidural dose. Drs Norman and Plaat are fortunate in that respect. We used patient-controlled analgesia partly for that reason. The advantages of the technique must be weighed against the risks. On present evidence, we do not believe that the advantage of rapidity of onset outweighs the potential risks and increased workload of the combined technique in early labour.