Single-dose intrathecal analgesia to control labour pain: Is it a useful alternative to epidural analgesia?

OBJECTIVE To examine the safety and efficacy of single-dose spinal analgesia (intrathecal narcotics [ITN]) during labour. QUALITY OF EVIDENCE MEDLINE was searched and the references of 2 systematic reviews and a meta-analysis were reviewed to find articles on obstetric analgesia and pain measurement. The 33 articles selected included 14 studies, 1 meta-analysis, and 2 systematic reviews, all providing level I evidence. MAIN MESSAGE The literature supports use of ITN as a safe and effective alternative to epidural anesthesia. The recent decrease in rates of episiotomies and use of forceps during deliveries means patients require less dense perineal anesthesia. The advantageof single-dose ITN is that fewer physicians and nurses are needed to administer it even though its safety and effectiveness are comparable with other analgesics. Use of ITN is associated with a shorter first stage of labour and more rapid cervical dilation. A combination of 2.5 mg of bupivacaine, 25 μg of fentanyl, and 250 μg of morphine intrathecally usually provides a 4-hour window of acceptable analgesia for patients without complications not anticipating protracted labour. The evolution in dosing of ITN warrants a re-examination of its usefulness in modern obstetric practice. CONCLUSION Physicians practising modern obstetrics in rural and small urban centres might find single-dose ITN a useful alternative to parenteral or epidural analgesia for appropriately selected patients.