Comparison of incremental spinal anesthesia using a 32-gauge catheter with extradural anaesthesia for elective...

Forty-three mothers who had requested regional anaesthesia for elective Caesarean section were allocated randomly to receive either extradural anaesthesia with pH-adjusted 2% lignocaine with 1/200,000 adrenaline, or incremental spinal anaesthesia using a 32-gauge catheter with 0.5% plain bupivacaine. Increments of lignocaine or bupivacaine were given with the aim of achieving a block from T4 to S5. The spinal catheter was quicker to place (median 3 min, range 1-45 min, compared with median 10 min, range 1.5-50 min) and spinal anaesthesia was quicker to establish (median 20 min, range 10-46 min compared with median 48 min, range 15-59 min) compared with the extradural technique. The maximum height of the spinal block was significantly higher (median T3-4, range T5-T3) than the extradural group (median T5, range T6-T3). The total dose of intrathecal 0.5% bupivacaine was unpredictable, with a mean dose of 2.7 ml and a range between 1.5 ml and 7.4 ml. Haemodynamic stability and the quality of the block were similar between the groups. There were two mild spinal-headaches in the spinal group. All the spinal catheters were removed intact.