Is opioid loading necessary before opioid/local anaesthetic epidural infusion? A randomized double-blind study in...

The effects of two different epidural loading doses administered before starting an opioid/low dose local anaesthetic infusion were examined in a randomized double-blind study during labour. Forty mothers were given either 10 ml 0.25% plain bupivacaine or 10 ml 0.125% plain bupivacaine containing 5 mcg of sufentanil followed in all cases by epidural infusion of 0.08% plain bupivacaine containing 0.2 mcg/ml of sufentanil, which was continued into the second stage. The quality of analgesia did not differ significantly between the groups in either the first or the second stage of labour: in each group 75% of women required 0 or 1 top-up during labour and verbal numerical pain scores were similar. Over 80% of women in each group reported a pain free second stage of labour. There were no differences in the mode of delivery between the groups with 60% of women in each group having a spontaneous vaginal delivery. The proportion of women with motor block increased with the duration of the epidural infusion, with no difference between the groups. There was no difference in the degree of maternal satisfaction assessed 24 hours after delivery, with 80% of women in each group awarding the maximum verbal numerical score for their satisfaction with epidural analgesia. The incidence of maternal side effects (nausea, vomiting, drowsiness and pruritus) was similar in the 2 groups as was neonatal outcome, assessed by Apgar and neurological and adaptive capacity scores and umbilical artery and vein pH. We conclude that opioid loading before opioid/low-dose bupivacaine epidural infusions is unnecessary.