Epidural Vs Combined Spinal-Epidural Labour Analgesia: Is it Associated with Adverse Uterine and Umbilical Flow Indices?

Objective: To assess and compare the consequences of different approaches of epidural and combined spinal, epidural analgesia on the umbilical and uterine artery flow velocity waveform indices, maternal haemodynamics and neonatal outcome in normal term labour. Design: A prospective, observational, randomised study. Settings: El-Hussien Hospital and Kuwait Maternity Hospital. Subjects and Methods: Sixty normal, term, singleton nulliparous parturients during active labour were randomly assigned to one of four regional blockade regimens: group-l (15-women) received epidural blockade with a 10ml -0.25% bupivacaine solution, group-II (15-women) received epidural blockade with a 10ml -0.25% bupivacaine solution plus 0.5ug/kg fentanyl, group-Ill (15 women) received combined spinal and epidural blockade with 0.25% bupivacaine solution and group-1V (15 women) received combined spinal and epidural blockade with 0.25% bupivacaine solution plus 0.5ug/kg fentanly. Each Doppler velocimetric study, conducted over 90 minutes after intravenous volume preload with 7-10 ml/kg of lactated Ringer's solution, was divided into three. Phases: 30 minutes of preanaesthetic, 30 minutes during epidural catheter placement "and dosing, and 30 minutes after establishing effective regional blockade. During each phase, maternal blood pressure and pulse were monitored every 10 minutes and Doppler recordings of the umbilical and uterine arteries were made at three separate intervals. Fetal heart rate and uterine activity monitoring were continued after each Doppler study session. Main Outcome Measures: Maternal haemodynamics (mean systolic and diastolic blood pressures and pulse rate), Doppler indices of the umbilical and uterine arteries (S/D ratio and PI), fetal heart rate, visual analogue scale (VAS) for pain assessment, and neonatal outcome (1and 5-minute Apgar Correspondence to: Dr. Hossam M. Al-Kady, The Dept. of Obst. & Gyn., Faculty of Medicine, Al-Azhar University, Cairo. scores, mean umbilical artery pH, mean birth weight and admissions to neonatal intensive care unit). Results: The mean systolic and diastolic blood pressures as well as pulse rate declined significantly with the dosing and establishment of regional blockades in the study groups (p*<0.05), but no women experienced hypotension. The difference among the study groups was not significant ( p+> 0.05). The mean fetal heart rate did not change significantly throughout the study periods (p*>0.05). The difference was not significant between the study groups ( p+0.05). In addition, mean systolic/diastolic (S/D) ratios and pulsatility indices (PI) of the umbilical and uterine arteries did not change significantly during the study ( p*>0.05). The neonatal outcome among the groups was similar (p+>0.05) with no adverse effects as the mean 1and 5-minute Apgar scores were >7, mean umbilical artery pH was >7.25 and no admissions to neonatal nursery for ventilation. It was found that the visual analogue scale (VAS) for labour pain assessment decreased significantly in all parturients during intra-and post-anaesthetic periods (p*<0.05). Conclusion: Effective epidural and combined epidural subarachnoid analgesia do not have a significant impact on the Doppler blood flow characteristics of utero-and fetoplacental circulation despite lowered maternal blood pressure and pulse rate. Adding fentanyl to bupivacaine for regional blockade during normal labour is an effective technique for pain relief as well as safe for mother and fetus. Larger longterm studies are needed to confirm the clinical impact of our findings particularly in long-term assessment of perinatal outcome.