Background: Lidocaine is used as a ‘test dose’ to detect misplacement of epidural catheters. When administered immediately after the initiation of a combined spinal epidural for labor analgesia, it was found to interfere with motor function. The authors hypothesized that an epidural test dose of 3 ml of 1.5% lidocaine injected immediately after the initiation of combined spinal epidural analgesia and followed by a continuous epidural infusion would prolong the duration of analgesia and decrease the incidence of breakthrough pain.
Material/Methods: Sixty nulliparous parturients were recruited for this randomized controlled trial. Combined spinal epidural analgesia was performed with intrathecal levobupivacaine 2.5 mg and fentanyl 25 μg. The
patients were randomized into three groups: group L receiving 3 ml of 1.5% epidural lidocaine, group S 3 ml of normal saline, and group C the control group receiving no test solution. An epidural infusion of 0.1% levobupivacaine and 2 μg of fentanyl/ml at 10 ml/hr was initiated immediately.
Their need for supplementary analgesia, duration of analgesia, sensory block, motor block, side-effects, and overall satisfaction were recorded.
Results: The breakthrough pain rate in all groups were similar. Their mean duration of analgesia (mean survival times) were not signifi cantly different. Group C had the lowest incidence of lower limb motor block. The satisfaction scores were signifi cantly highest in group L.
Conclusions: The administration of epidural lidocaine and saline immediately after intrathecal levobupivacaine 2.5 mg and fentanyl 25 μg did not reduce the incidence of breakthrough pain in combined spinal epidural labor.

Keywords: Analgesia, Obstetrical, Analgesia, Epidural, Anesthetics, Local - pharmacology, Injections, Spinal, Labor, Obstetric - drug effects, Lidocaine - pharmacology, Pain Measurement, Pregnancy