SummaryThe combined spinal-epidural technique has been used increasingly over the last decade. Combined spinal-epidural may achieve rapid onset, profound regional blockade with the facility to modify or prolong the block. A variety of techniques and devices have been proposed. The technique cannot be considered simply as an isolated spinal block followed by an isolated epidural block as combining the techniques may alter each block. This review concentrates on technical and procedural aspects of combined spinal-epidural. Needle-through-needle, separate-needle and combined-needle techniques are described and modifications discussed. Failure rates and causes are reviewed. The problems of performing a spinal block before epidural blockade (potential for unrecognised placement of an epidural catheter, inability to detect paraesthesia during epidural placement, difficulty in testing the epidural, delay in positioning the patient) are described and evaluated. Problems of performing spinal block after epidural blockade (risk of catheter or spinal needle damage) are considered. Mechanisms of modification of spinal blockade by subsequent epidural drug administration are discussed. The combined spinal-epidural technique (CSE) involves intentional subarachnoid blockade and epidural catheter placement during the same procedure. CSE allows a rapid onset of neuraxial blockade, which can subsequently be prolonged or modified. Ideally it combines the best features of spinal blockade (rapid onset, profound blockade, low drug dosage) and epidural blockade (titratable levels, ability to prolong indefinitely) and avoids their respective disadvantages (spinal: single-shot nature, unpredictable level of blockade; epidural: missed segments, incomplete motor block, poor sacral spread, local anaesthetic toxicity). However, it is a more complicated technique than either block alone and produces a multicompartment block. This introduces the potential for new complications and the modification of existing complications. CSE cannot be considered as simply a spinal block followed by an epidural block. A variety of techniques, equipment and regimens have been described. New complications and reasons for technical failure are encountered. Epidural injection may modify the spinal block and epidural drugs may not behave as they would without prior dural puncture.
Review aims and methodThis review examines the current literature on technical aspects of the CSE technique and factors that distinguish it from either spinal or epidural blockade. The review does not consider different drug regimens or address the role of the technique as analgesia during labour. Owing to the limited number of randomised controlled trials and other high-quality research, the review is descriptive. Articles were found by Medline search through the years 1975-1999 using the search words 'spinal' or 'subarachnoid' and 'epidural' or 'extradural'. Reference lists in these publications were searched. The major anaesthetic journals were hand searched. This search identified 5...
