Uterine activity in dysfunctional labour and target uterine activity to be aimed with oxytocin titration

Analgesic efficacy using loss of resistance to air vs. saline in combined spinal epidural technique for labour analgesia

Identification of the epidural space is often performed using the loss of resistance technique to either air or saline. We sought to investigate if the medium used affected the quality of analgesia obtained by parturients who received labour epidurals. We conducted a retrospective audit of labour epidurals performed on nulliparous parturients in our institution from May 2003 to March 2005. All epidural catheters were inserted by senior obstetric anaesthetists using a combined spinal epidural technique. The following information was recorded: parturients' demographic data, loss of resistance technique used, type and amount of local anaesthetic solution administered, complications encountered during procedure, pre-block and post-block pain scores, incidence of breakthrough pain requiring supplemental medication and post-block side-effects. Data from 2848 patients were collected and analysed; 56% of patients made up the saline group and 44% the air group. Patients in both groups had similar demographic profiles and similar incidences of complications and post-block side-effects. However patients in the air group had a higher incidence of recurrent breakthrough pain P = 0.023). We also identified three other factors that were associated with an increased incidence of recurrent breakthrough pain; administration of pre-block oxytocin, sitting position of the parturient during the procedure and the use of intrathecal bupivacaine for induction of analgesia. Our findings suggest that a loss of resistance to air is associated with a higher incidence of recurrent breakthrough pain among parturients who received combined spinal epidural analgesia for labour than a loss of resistance to saline.

Outcomes of labours augmented with oxytocin

OBJECTIVE

To highlight the differences in mode of delivery between women augmented with intravenous oxytocin because of failure to progress in labour with those who labour without the need for augmentation.

STUDY DESIGN

An incidence study over a 5-year-period in a tertiary referral hospital comparing 1097 nulliparous women who were augmented in labour with 2745 nulliparous women who did not need augmentation. Only labours of spontaneous onset in the pregnancies of women at term were studied. The incidence of pregnancy outcomes were assessed by presenting estimates of relative risk (RR) and their 95% confidence intervals (CI).

RESULTS

Only 51.1% of women who received augmentation achieved a normal vaginal delivery compared with 76.5% of women who did not need augmentation (RR 0.67; CI 0.63-0.71). Contributory factors to this disparity included a greater number of Caesarean sections (14.4% versus 6.6%; RR 2.18 CI 1.74-2.67), forcep deliveries (12.8% versus 5.3%; RR 2.41 CI 1.93-3.01) and ventouse deliveries (21.7% versus 11.5%; RR 1.89 CI 1.62-2.21) being performed among augmented labours as compared to normal progressive labours.

CONCLUSION

Significant improvements in the management of labours which fail to progress are needed if normal vaginal delivery rates are to approach those seen in labours which progress without the need for augmentation.