Walking epidurals for labour analgesia: do they benefit anyone?

Abstract

The ‘‘walking epidural’’ first appeared in the early 1990s. In some ways, it tested our widely held beliefs about how to provide effective and safe labour epidural analgesia and responded to women’s requests to have effective labour analgesia without being confined to bed. In the first versions of the walking epidural, the combined spinalepidural (CSE) technique was used. It provided initial analgesia with intrathecal narcotic, which was followed by a more standard continuous epidural infusion. This novel technique challenged our assumptions about the amount of neuraxial medication needed to initiate and maintain labour analgesia. Many labour analgesia studies ensued that resulted in significant changes to both the technique and the dosing strategies, and they led to a deeper understanding of the way in which local anesthetics and opioids work alone and synergistically in the neuraxium. Critical assessment of ambulation in labour with an epidural in situ has provided enormous benefit to women in labour, has changed how anesthesiologists provide labour epidural analgesia, and has added to the body of literature to convince our skeptical colleagues in obstetrics that epidurals don’t necessarily mean an operative delivery. The end result of this scientific activity is patient-controlled labour epidural analgesia with low-dose solutions—there are so many benefits in that simple phrase. So, why has the enthusiasm for walking epidurals faded? While it is true that ambulation per se has not been shown to alter labour outcome, maintaining mobility appeals to women although they may be at the point of requiring neuraxial analgesia. The fact that they may not take full advantage of this opportunity does not negate its other benefit of minimizing motor block. It is also true that the ‘‘mobile mom’’ can create more work for staff; however, once anesthesiologists establish management and safety protocols for ambulation, the added work belongs to the nurse and/or the midwife, many of whom support maintaining mobility. Safety of the perambulating parturient with an epidural has been established—her balance is just as good as any pregnant woman’s is at term, blood pressure is possibly more stable than in the woman who remains lying in bed and the fetus probably benefits from complete absence of aortocaval compression. So, why has the movement to mobility stalled? Have anesthesiologists lost their taste for the CSE because of fetal bradycardia and maternal pruritus? While CSEs opened the door to mobility, it has been clearly proven that low-dose epidurals with no intrathecal component work incredibly well and allow for safe ambulation. Perhaps we should reflect on the reason this ‘‘fad’’ started. Standard (aka dense) epidural analgesia did not always lead to maternal satisfaction with the analgesia because of the sense of loss of body control and the increased need for an instrumental vaginal delivery, especially if the mother was primiparous. So, intrepid obstetrical anesthesiologists began to challenge the status quo and experiment with the techniques of using intrathecal lipid soluble narcotics for initial analgesia, progressively more dilute solutions in the epidural space for subsequent analgesia, and then applying patient-controlled analgesia technology. Many studies used the ability to ambulate as one of the required outcomes, as it R. Preston, MD (&) Department of Anesthesia, BC Women’s Hospital and Health Centre, Rm 1Q72, 4500 Oak Street, Vancouver, BC V6H 3N1, Canada e-mail: rpreston@cw.bc.ca