Publications of Faculty of Medicine:Selective Bilateral Lumbar Sympathetic Blocks Speed the Second Stage of Induced Labor in Nulliparous Women: A Comparison with Conventional Epidural Block : Abstract

Rapid cervical dilatation reportedly accompanies lumbar sympathetic blockade, whereas epidural analgesia is associated with slow labor. We compared the effects of initial bilateral selective lumbar sympathetic block with those of epidural analgesia on labor speed and delivery mode. Methods: The study included 50 full-term nulliparous patients whose labors were induced randomly received initial bilateral lumbar sympathetic block (n = 25) or epidural analgesia (n= 25). The latter patients received 10 ml ropivacaine, 0.2%; 50 ttg fentanyl; and 100 mg epinephrine epidurally. Patients to have lumbar sympathetic blocks received 10 ml ropivacaine, 0.2%; 25 mg fentanyl; and 50 ttg epinephrine bilaterally and epidural catheters were inserted. Subsequently, labour pain were managed with continuous epidural block in all patients. Results: Cervical dilatation occurred more quickly (49 vs. 105 min/cm cervical dilatation) during the first 2 h of analgesia in patients having lumbar sympathetic blocks than in patients having epidurals. The second stage of labor was briefer in patients having lumbar sympathetic blocks than in those having epidurals (95 vs. 216 min; P < 0.05). Sixteen patients having lumbar sympathetic block and twelve having epidurals delivered spontaneously, whereas seven patients in each group had instrument-assisted vaginal deliveries. Cesarean delivery for fetal bradycardia occurred in one patient having lumbar sympathetic block. Cesarean delivery for dystocia occurred in six patients having epidurals compared with one patient having lumbar sympathetic block. Visual analog pain scores differed only at 60 min after block. Conclusions: Nulliparous parturients having incInced labor and receiving initial lumbar sympathetic blocks had faster cervical dilatation during the first 2 h of analgesia, shorter second-stage labors, and a trend toward a lower dystocia cesarean delivery rate than did patients having epidural analgesia. The effects of lumbar sympathetic block on labor need to be determined in other patient groups. These results may help define the tocodynamic effects of regional labor analgesia.