Patient-controlled analgesia for labour using remifentanil: a feasibility study.

We have investigated the efficacy and safety of remifentanil in a patient-controlled analgesia device for labour in 21 women. Remifentanil was available in increasing doses (bolus doses 0.25-1.0 microg x kg(-1)) with and without a background infusion (0.025-0.05 microg x kg(-1) x min(-1)). A lockout time of 2 min was used. Thirteen out of 21 (62%) women chose to continue using remifentanil up to and during delivery. Nineteen out of 21 (90%) achieved a reduction in pain score from baseline. Using a VAS of 0-10 cm the median maximum reduction in pain score was 3 cm (range 0-8 cm). There was a significant reduction (P<0.05) from baseline pain scores (median= 8 cm) to scores at bolus doses in the range 0.25-0.5 microg x kg(-1) (median=5 cm). There were no significant reductions in the fetal heart rate. Apgar scores and cord blood gas analyses remained within normal limits. We conclude that a remifentanil patient-controlled analgesia system (bolus doses 0.25-0.5 microg x kg(-1), without a background infusion) may safely provide worthwhile, although incomplete, analgesia for labour.