Epidural analgesia is the gold standard for the provision of pain relief during labor. Conventional epidural analgesia is often associated with a profound motor block, the need for continuous fetal heart rate monitoring, intravenous infusions, the need for bladder catheterization and in general with a parturient unable to mobilize. This can occasionally lead to unfavorable obstetric outcomes, such as a prolonged duration of the first and second stage of labor, an increased incidence of instrumental delivery and an increased need for augmentation of labor with oxytocin infusions.

The option for the parturient of being mobile during labor is increasingly being offered in many obstetric units with the advent of new epidural adjuvant drugs and novel epidural delivery systems. This way, very low concentration local anaesthetic solutions can be used, which reduces the total dose of local anaesthetic solution administered. This allows the preservation of lower limb motor function in the parturient, facilitating maternal ambulation during labor. the earliest version of a ‘walking epidural’ was first described in the 1990s and consisted of a combined spinal epidural (CSE) technique with an initial intrathecal administration of opioid only (with or without a small amount of local anaesthetic), followed by a continuous epidural infusion. However, nowadays, ‘mobile’ epidural techniques can be achieved without an intrathecal opioid injection (with the associated drawbacks, such as the complexity of the CSE technique, the risks of postdural puncture headache, infection, fetal bradycardia and maternal pruritus), with an epidural-only technique.

Ambulatory epidural techniques allow parturients to safely stand and walk during labor. This creates a high degree of maternal satisfaction and increases the parturient’s sense of autonomy. It is thought that the ability to ambulate, even if ambulation is not eventually accomplished, improves the labor and birth experience. Moreover, parturients usually dislike the dense sensory and motor block associated with conventional epidural analgesia. Additionally, even though it was considered initially that the possibility of postural hypotension with a standing parturient would complicate attempts at ambulation, it has in fact been shown that maternal blood pressure is more stable in the ambulant parturient due to a reduced incidence of aortocaval compression in the standing parturient as compared to the parturient confined in bed. The lower incidence of aortocaval compression can also result in a reduction of untoward fetal heart rate changes, improved APGAR scores and an improved umbilical cord gas profile in the neonate.

Additional advantages of ambulatory techniques include a reduction in the possibility of deep venous thrombosis with ambulation and a reduction in the need for urinary catheterization as compared to conventional epidural techniques, since the retention of normal bladder function and sensation of voiding with low concentration solutions make urinary instrumentation unnecessary.

Regarding the effect of maternal ambulation on the course of labor, it is believed that an upright position during the course of labor might potentially decrease the incidence of dystocia by improving fetal descent through the effect of gravity and can also lead to an enhancement of pelvic diameter and increased coordination of uterine contraction frequency and intensity. Studies have shown that there may be a significant reduction in instrumental or caesarean delivery rate with low dose CSE followed by low concentration epidural infusion or by low concentration epidural infusion only, possibly as a result of ambulation. the possibility though that this can also be due to the lower concentration of solutions used cannot be completely ruled out.

In conclusion, ambulatory techniques in the labor ward are a reasonable option with a variety of distinct benefits and can be used without jeopardising the safety of the mother and the fetus.

References

1. Preston R. Walking epidurals for labor analgesia: Do they benefit anyone?Can J Anaesth 2010;57:103–106.

2. Stewart S, Fernando R. Maternal ambulation during labor. Curr Opin Anaesthesiol 2011;24:268–273.

3. Wilson MJ, MacArthur C, Cooper GM, et al. Ambulation in labour and delivery mode: a randomised controlled trial of high-dose vs mobile epidural analgesia. Anaesthesia 2009;64:266–272.

4. Wilson MJ, Macarthur C, Shennan A; COMET Study Group (UK). Urinary catheterization in labour with high-dose vs mobile epidural analgesia: a randomized controlled trial. Br J Anaesth 2009;102:97–103.

5. de la Chapelle A, Carles M, Gleize V, et al. Impact of walking epidural analgesia on obstetric outcome of nulliparous women in spontaneous labour. Int J Obstet Anesth 2006;15:104–108.