EXTRADURAL CLONIDINE COMBINED WITH SUFENTANIL AND 0.0625-PERCENT BUPIVACAINE FOR ANALGESIA IN LABOR

We have studied the use of clonidine combined with low doses of sufent anil and bupivacaine in 45 parturients requiring extradural analgesia for the first stage of labour, in a double-blind, randomized study. We gave 0.0625% bupivacaine 10 ml containing 1:200 000 adrenaline and su fentanil 10 mu g (1 ml) to which was added 0.9% saline, or clonidine 1 00 or 150 mu g (1 ml). We compared the quality (VAS scores) and durati on of analgesia, motor block, maternal haemodynamic state (mean arteri al pressure and heart rate) and fetal and maternal side effects. Mean duration of anaesthesia was prolonged slightly: 105 (SD 21) min withou t clonidine, 130 (28) min with clonidine 100 mu g (P<0.05 vs control) and 144 (40) min with clonidine 150 mu g (P<0.01 vs control, ns vs 100 mu g). There were no differences in VAS scores, onset times, heart ra te, ventilatory frequency, motor block, sedation, pruritus or bradycar dia between the groups. Analgesia was associated with a reduction in m ean arterial pressure with clonidine. However, these adverse side effe cts were of minor clinical importance regardless of the extradural clo nidine dose, except for a high incidence of fetal heart tracing abnorm alities when clonidine 150 mu g was used. These effects associated wit h a limited effect on analgesia may curtail the widespread use of clon idine as an adjunct to extradural 0.0625% bupivacaine with sufentanil 10 mu g during labour.