Brownridge, in 1979, described the double-segment technique for Caesarean section. This involved the introduction of an epidural catheter and test dose, followed by a standard subarachnoid puncture one or two segments distally using a 26-gauge spinal needle (2).
Carrie and O'Sullivan (1984) reported a single-space technique for Caesarean section, where epidural puncture was performed with a 16-gauge Tuohy needle, through which a spinal needle was inserted and subarachnoid block initiated (Figure 54.2). Following removal of the spinal needle an epidural catheter for later use was inserted (3). This forms the basis of the currently popular techniques.
Equipment:
Packaged sets for CSE are now available from several manufacturers. These kits include various gauges of spinal needles which are usually 10-13mm longer than the Tuohy needle (Figure 51.1).
The main advantages claimed for these sets are:
1. improved fit of the spinal needle within the Tuohy needle,
2. reduced friction between the needles,
3. diminished likelihood of damage to the tip of the spinal needle, and
4. reduced potential for the generation of injectable metal fragments.
Innovative designs have been described. One includes a "back eye" in the Tuohy needle (Figure 54.1) for easier spinal needle insertion (Chapter 54), and another incorporates a second lumen alongside the shaft of the Tuohy needle (1).
References:
1. FELSBY S, JUELSGAARD P. Combined spinal and epidural anesthesia. Anesth Analg 1995 80:821-826.
2. BROWNRIDGE P. Central neural blockade and caesarean section. Part I: review and case series. Anaesth Intensive Care 1979 7:33-41
3. CARRIE LES, O'SULLIVAN GM. Subarachnoid bupivacaine 0.5% for Caesarean section. Eur J Anaesthesiol 1984 1:275-283.