CONTINUOUS SUBARACHNOID INFUSION OF 0.125% BUPIVACAINE FOR ANALGESIA DURING LABOUR

We have studied 20 primiparous women requesting pain relieffor labour, to determine the feasibility of subarachnoid infusionsof bupivacaine for analgesia. A 28-gauge catheter was insertedinto the subarachnoid space through a modified 22-gauge Sprotteneedle. After a bolus dose of up to 7.5 ml of 0.25% bupivacaine,a continuous infusion of 0.725 % bupivacaine was commenced.If analgesia became inadequate, additional 0.5-ml boluses of0.25% bupivacaine were given (mean number of top-ups 2.8; range0–6). Persistent perineal pain occurred in four womenand this was relieved by 0.5% hyperbaric bupivacaine. Analgesiawas good or excellent in 75 of 20 mothers within 70 min andin 79 of 20 within 30 min, and it remained good or excellentthroughout labour and delivery. Motor block was complete inthree of the women who needed hyperbaric 0.5% bupivacaine. Therewere no difficulties with insertion of the catheter, no episodesof significant hypotension (systolic arterial pressure lessthan 700 mm Hg) or postdural puncture headache. Seven mothersdelivered their babies vaginally, eight required assistancewith forceps and five needed a Caesarean section.