Intravenous fentanyl PCA during labour

To evaluate the usefulness of intravenous patient-controlled analgesia (PCA) fentanyl for labour analgesia, its effectiveness for maternal pain and safety for the fetus and newborn.

Twenty primigravidas were randomised to receive intravenous PCA fentanyl or epidural analgesia for labour pain. Maternal pain, heart rate and arterial oxyhaemoglobin saturation (SpO2) were monitored. Fetal and neonatal monitoring included cardiotocogram (CTG), APGAR, neurological scoring and static-charge-sensitive bed (SCSB) recording for 12 hr postnatally with ECG and SpO2. Fentanyl concentrations and pH of umbilical artery and vein were analysed.

Initially, epidural analgesia was more effective (P = 0.01), and three patients in the fentanyl group were given epidural due to unsatisfactory pain relief. Overall satisfaction for analgesia did not differ between the groups. Maternal side-effects were more frequent in the fentanyl group (dizziness and tiredness most often, P = 0.0001). Severe side-effects were not reported. In CTG there were no differences between groups. All the newborns were healthy, APGAR and pH were normal. Naloxone was not used. Neurological scoring was similar in both groups. In 12 hr monitoring heart rate, breathing frequency and movement time were similar in both groups, but SpO2 was lower in the fentanyl group (P < 0.001). Umbilical cord fentanyl concentrations were low or beyond the detection limit.

Intravenous fentanyl can be used for labour analgesia with the doses reported here as an alternative to epidural analgesia. However, the fetus and neonate must be appropriately monitored. Naloxone and oxygen should be available if neonatal distress occurs.