Postural stability following ambulatory regional analgesia for labor

The safety of mobilization following low-dose regional analgesia in parturients remains controversial. Previous studies have demonstrated preserved balance function despite clinically elicited sensory deficits. The aim of this study was to use the Balance Master 6.1, a device capable of real-time analysis of ambulation, to score the performance of basic maneuvers following initiation of low-dose combined spinal-epidural analgesia in laboring women compared with pregnant and nonpregnant controls.

Using the Balance Master, balance function during the performance of several simple tasks, including walking and standing up from a sitting position, was evaluated in a prospective, controlled, observational study with 50 laboring women after combined spinal-epidural analgesia compared with 50 pregnant and 50 nonpregnant controls.

Nonpregnant women scored significantly better results in 6 of the 13 measured balance function parameters compared with both the combined spinal-epidural and pregnant control groups. Compared with the nonpregnant subjects, the pregnant groups generated less force standing up from the sitting position (P < 0.0001), walked more slowly (P = 0.0067), and took shorter steps (P < 0.0001). They also took longer to step up onto and over a 20-cm-high obstacle (P < 0.0001), and they generated less force while stepping up. Initial spinal analgesia in laboring women did not significantly affect performance in comparison to the pregnant controls. Thirty-four percent of women in the combined spinal-epidural group required supplemental epidural analgesia following the initial spinal injection (n = 17) before testing; they had significantly impaired balance function in four tests compared with those receiving a spinal injection only (n = 33).

Being pregnant at term significantly affects balance function, although initial low-dose spinal-epidural analgesia does not impair function further. Subsequent supplemental epidural analgesia may have a detrimental effect on balance, but properly designed studies are awaited to confirm this. This study supports the practice of allowing laboring women with initial low-dose spinal-epidural analgesia to ambulate, but indicates that further studies need to be conducted on the effects of subsequent epidural supplementation.