Epidural infusions of bupivacaine and diamorphine in labour

Three different concentrations of bupivacaine, 0.125%, 0.062% and 0.031%, all with diamorphine 0.0025%, were given as an epidural infusion at 10 ml.h‐1 to 63 mothers in labour. When the three infusions were compared, significant differences were found in maternal requirements for top‐ups and the degree of motor block, but there were no differences in the pain scores. The reduced motor block was not associated with a reduction in the instrumental delivery rate.