The WE Pilot Study: Walking Epidurals

Historically, women have labored in the upright position and it is only in the twentieth century that hospitalization and bedrest have become the standard of care during labor in most developed countries. This practice has been especially encouraged in patients laboring under neuraxial analgesia (epidural or combined spinal-epidural) because of the possibility of lower limb weakness associated with the use of local anesthetic agent.

Walking during labor has been associated with positive outcomes such as a reduction in the duration of labor, reduced incidence of assisted vaginal delivery and reduction of the rate of caesarean section in women in upright position compared to those bedridden, without being associated with negative effects on mothers' and babies' well-being. Proposed hypothesis to explain the reduction in duration of labor are an improved uterine contractility and an enhancement of pelvic diameter.

Impacts of ambulation during labor have also been studied in women with neuraxial analgesia but unfortunately, in these studies, a significant proportion of patients allowed to walk did not and, if they did, the time spent ambulating was extremely variable.

The reluctance to allow women to walk during neuraxial analgesia is mainly because of concerns of a possible motor block and of orthostatic hypotension. The combination of a low dose of local anesthetic agent and of an opioid for CSE has been shown to provide good analgesia while minimizing impairment of lower limbs' strength. Since a certain degree of leg weakness can occur even with low concentrations of local anesthetic agent, it is recommended to evaluate the presence of a motor block before allowing ambulation with neuraxial analgesia. For safe ambulation, meeting the following conditions is generally recommended: no lower limb weakness, ability to perform straight leg raise and complete hip flexion, performance of a partial knee bend, ability to step up on a stool with both legs, trial of walking witnessed by a member of the staff.

The other major concern related to ambulatory neuraxial analgesia is the risk of fall secondary to hypotension. Hypotension mainly occurs at initiation of neuraxial analgesia and is usually easily treated with small doses of phenylephrine and ephedrine, giving additional intravenous fluids and by placing the patient in the full lateral position. Interestingly, blood pressure seems to be more stable in the ambulant parturient than in the supine one probably due to the reduced incidence of aortocaval compression when standing. Since hypotension is mainly seen after initiation of neuraxial analgesia, most studies will allow at least 30 minutes after the bolus injection of the local anesthetic agent and blood pressure is verified in the erect position before ambulation is allowed.