An optimal epidural catheter placement site for post-cesarean section analgesia with double-space technique combined spinal–epidural anesthesia: a retrospective study

BACKGROUND: Epidural anesthesia affects lower extremities, which often prevents early mobilization postoperatively. The incidence of numbness and motor weakness in the lower extremities with respect to epidural catheter placement site in cesarean section (CS) is uncertain. We aimed to investigate the effect of catheter placement site on postoperative lower extremities numbness and motor weakness in patients who received combined spinal–epidural anesthesia (CSEA) for CS including analgesic effects and optimal epidural placement site in CS. METHODS: We retrospectively included 205 patients who underwent CS with CSEA at the University of Tsukuba Hospital between April 2018 and March 2020, and assessed numbness and motor weakness in the lower extremities. We also examined whether differences in the intervertebral space of epidural catheter placement and epidural effect on the lower extremities are related to analgesic effects. ANOVA and Mann–Whitney U test were used for statistical analysis. RESULTS: The incidence of numbness and motor weakness were 67 (33%) and 28 (14%), respectively. All patients with motor weakness had numbness. A more caudal placement was associated with increased incidence of affected lower extremities. There was no significant difference in the analgesic effect depending on the catheter placement site. When the lower extremities were affected, the number of additional analgesics increased (p < 0.001). Patient-controlled epidural analgesia was used for fewer days in patients with motor weakness (p = 0.046). CONCLUSION: In CS, epidural catheter placement at T10–11 or T11–12 interspace is expected to reduce effect on the lower extremities and improve quality of postoperative analgesia.