[Epidural anesthesia for labor]. / L'anesthésie péridurale pour le travail.

Since the last decade, lumbar epidural analgesia has gained widespread use in obstetrics. Approximately 80% of parturients receive epidural analgesia for labour and vaginal delivery as well as caesarean section in most centres. There is little doubt that the most successful application of epidural analgesia during labour, considered by more than 75% of primiparas as extremely painful. The quality of analgesia is far superior to that which can be achieved by either parenteral or inhalation approaches and, unlike these methods, the mother remains alert. Epidural analgesia also prevents, or greatly diminishes, most of the physiological and chemical responses to labour pain that can be considered as stress responses, similar to those that have been described during surgery. There are considerable benefits, therefore, to both mother and child. Thus, epidural analgesia usually can be extended to relieve both uterine pain and pain related to distension of the lower birth canal, as well as providing analgesia for forceps delivery or caesarean section. Epidural analgesia allows the mother to be awake, minimizes or completely avoids the problems of maternal aspiration and avoids neonatal drug depression from general anaesthetics. If the most popular indication for epidural analgesia is the provision of pain relief, there are certain complications of pregnancy in which epidural analgesia appears to be indicated on therapeutic grounds such as pregnancy-induced hypertension, breech delivery, multiple pregnancy, incoordinate uterine action and fetal and/or maternal medical complications.

[Opiates for epidural analgesia: for or against?]. / Opiacés pour l'analgésie péridurale: pour ou contre?

Epidural opiate administration is routinely used by many anaesthesiologists involved in obstetric anaesthesia. Epidural injection of a local anaesthetic combined with an opioid generates a more rapid onset of more profound analgesia with little motor blockade. Thus pain relief lasts longer than after either drug alone. A combination of dilute concentrations of bupivacaine and opioids lowers the risk of systemic local anaesthetic toxicity significantly. Fentanyl was the first opioid widely used as an adjunct to local anaesthetics for labour analgesia. An initial dose of fentanyl 50 micrograms combined with 0.25% or 0.125% bupivacaine can produce good initial analgesia for most laboring parturients. A continuous infusion of 0.125% or 0.0625% bupivacaine with 1 microgram.ml-1 fentanyl at 10-12 ml.h-1 will maintain good pain relief throughout parturition. No adverse effects on either the mother or the neonate have been attributed to this technique. Recently, sufentanil was introduced in obstetric analgesia. Sufentanil appears to induce a faster onset of more profound, long lasting analgesia with extremely low concentrations of bupivacaine than that with fentanyl. The reduction of the total amount of bupivacaine is correlated with a significant decrease in motor blockade and instrumental deliveries. There were no adverse maternal or fetal effects and umbilical cord levels were too low to be detected.