The effect of the addition of ropivacaine or bupivacaine upon pruritus induced by intrathecal fentanyl in labour

Sixty patients in early labour were randomly allocated to one of three groups. The control group received intrathecal fentanyl 25 microg, the ropivacaine group received intrathecal fentanyl 25 microg and ropivacaine 2.5 mg while the bupivacaine group received intrathecal fentanyl 25 microg and bupivacaine 2.5 mg. The incidence of pruritus was 100% in controls, compared with 85% in the ropivacaine group (not significant) and 75% in the bupivacaine group (p = 0.003). The severity of pruritus was significantly less in the ropivacaine (p = 0.006) and bupivacaine (p = 0.001) groups. Most patients developed pruritus by 30 min. Pruritus above the abdomen was not reduced in patients receiving local anaesthetics. There were no significant differences in the mean pain visual analogue score, systolic blood pressure, maternal heart rate and upper level of reduced pin-prick sensation in the first 30 min. Intrathecal ropivacaine and, more so, intrathecal bupivacaine reduce the incidence and severity of pruritus from intrathecal fentanyl for labour analgesia.