Comparison of continuous spinal and epidural analgesia for pain relief in labour

We have compared continuous spinal analgesia with continuous epidural analgesia for pain relief in labour. Twenty-six women were randomly allocated to receive either epidural 0.25% bupivacaine 5-10 ml via a 20 gauge catheter inserted through a 16 gauge Tuohy needle or intrathecal 0.25% bupivacaine 0.5-1.0 ml via a 32 gauge catheter inserted through a 24 gauge Sprotte needle. This was supplemented with fentanyl 5-10 mcg (spinal) or 1 mcg per kg (epidural) if analgesia was unsatisfactory. Outcome was measured by the success and timing of the procedure, time to analgesia, amount of drug given, visual analogue scoring of pain relief by the patient and an observer and degree of motor block. Onset time and dosage were significantly reduced in the continuous spinal group. Two catheters failed to feed in the spinal group. One catheter became displaced in each group. Pain relief was satisfactory in all patients and none had post-dural puncture headache. Continuous spinal analgesia may offer significant advantages over epidural analgesia but technical difficulties remain with the present equipment. The reasons for the withdrawal of the spinal catheters in the United States of America are discussed.